2492 lines
83 KiB
C
2492 lines
83 KiB
C
/*************************************************************************\
|
|
* Module Name: Lines.c
|
|
*
|
|
* Contains most of the required GDI line support. Supports drawing
|
|
* lines in short 'strips' when clipping is complex or coordinates
|
|
* are too large to be drawn by the line hardware.
|
|
*
|
|
* Copyright (c) 1990-1996 Microsoft Corporation
|
|
* Copyright (c) 1993-1996 Matrox Electronic Systems, Ltd.
|
|
\**************************************************************************/
|
|
|
|
#include "precomp.h"
|
|
|
|
// The MGA's hardware coordinates are limited to 16-bit signed values:
|
|
|
|
#define MIN_INTEGER_BOUND (-32767)
|
|
#define MAX_INTEGER_BOUND (32767)
|
|
|
|
///////////////////////////////////////////////////////////////////////
|
|
|
|
// We have to be careful of arithmetic overflow in a number of places.
|
|
// Fortunately, the compiler is guaranteed to natively support 64-bit
|
|
// signed LONGLONGs and 64-bit unsigned DWORDLONGs.
|
|
//
|
|
// UUInt32x32To64(a, b) is a macro defined in 'winnt.h' that multiplies
|
|
// two 32-bit ULONGs to produce a 64-bit DWORDLONG result.
|
|
//
|
|
// UInt64By32To32 is our own macro to divide a 64-bit DWORDLONG by
|
|
// a 32-bit ULONG to produce a 32-bit ULONG result.
|
|
//
|
|
// UInt64Mod32To32 is our own macro to modulus a 64-bit DWORDLONG by
|
|
// a 32-bit ULONG to produce a 32-bit ULONG result.
|
|
//
|
|
// 64 bit divides are usually very expensive. Since it's very rare
|
|
// that we'll get lines where the upper 32 bits of the 64 bit result
|
|
// are used, we can almost always use 32-bit ULONG divides. We still
|
|
// must correctly handle the larger cases:
|
|
|
|
#define UInt64Div32To32(a, b) \
|
|
((((DWORDLONG)(a)) > ULONG_MAX) ? \
|
|
(ULONG)((DWORDLONG)(a) / (ULONG)(b)) : \
|
|
(ULONG)((ULONG)(a) / (ULONG)(b)))
|
|
|
|
#define UInt64Mod32To32(a, b) \
|
|
((((DWORDLONG)(a)) > ULONG_MAX) ? \
|
|
(ULONG)((DWORDLONG)(a) % (ULONG)(b)) : \
|
|
(ULONG)((ULONG)(a) % (ULONG)(b)))
|
|
|
|
#define SWAPL(x,y,t) {t = x; x = y; y = t;}
|
|
|
|
FLONG gaflRound[] = {
|
|
FL_H_ROUND_DOWN | FL_V_ROUND_DOWN, // no flips
|
|
FL_H_ROUND_DOWN | FL_V_ROUND_DOWN, // FL_FLIP_D
|
|
FL_H_ROUND_DOWN, // FL_FLIP_V
|
|
FL_V_ROUND_DOWN, // FL_FLIP_V | FL_FLIP_D
|
|
FL_V_ROUND_DOWN, // FL_FLIP_SLOPE_ONE
|
|
0xbaadf00d, // FL_FLIP_SLOPE_ONE | FL_FLIP_D
|
|
FL_H_ROUND_DOWN, // FL_FLIP_SLOPE_ONE | FL_FLIP_V
|
|
0xbaadf00d // FL_FLIP_SLOPE_ONE | FL_FLIP_V | FL_FLIP_D
|
|
};
|
|
|
|
//////////////////////////////////////////////////////////////////////////
|
|
// General defines for bHardwareLine
|
|
|
|
BOOL bHardwareLine(PDEV*, POINTFIX*, POINTFIX*);
|
|
|
|
#define HW_FLIP_D 0x0001L // Diagonal flip
|
|
#define HW_FLIP_V 0x0002L // Vertical flip
|
|
#define HW_FLIP_H 0x0004L // Horizontal flip
|
|
#define HW_FLIP_SLOPE_ONE 0x0008L // Normalized line has exactly slope one
|
|
#define HW_FLIP_MASK (HW_FLIP_D | HW_FLIP_V | HW_FLIP_H)
|
|
|
|
#define HW_X_ROUND_DOWN 0x0100L // x = 1/2 rounds down in value
|
|
#define HW_Y_ROUND_DOWN 0x0200L // y = 1/2 rounds down in value
|
|
|
|
LONG gaiDir[] = { 0, 1, 7, 6, 3, 2, 4, 5 };
|
|
|
|
FLONG gaflHardwareRound[] = {
|
|
HW_X_ROUND_DOWN | HW_Y_ROUND_DOWN, // | | |
|
|
HW_X_ROUND_DOWN | HW_Y_ROUND_DOWN, // | | | FLIP_D
|
|
HW_X_ROUND_DOWN, // | | FLIP_V |
|
|
HW_Y_ROUND_DOWN, // | | FLIP_V | FLIP_D
|
|
HW_Y_ROUND_DOWN, // | FLIP_H | |
|
|
HW_X_ROUND_DOWN, // | FLIP_H | | FLIP_D
|
|
0, // | FLIP_H | FLIP_V |
|
|
0, // | FLIP_H | FLIP_V | FLIP_D
|
|
HW_Y_ROUND_DOWN, // SLOPE_ONE | | |
|
|
0xffffffff, // SLOPE_ONE | | | FLIP_D
|
|
HW_X_ROUND_DOWN, // SLOPE_ONE | | FLIP_V |
|
|
0xffffffff, // SLOPE_ONE | | FLIP_V | FLIP_D
|
|
HW_Y_ROUND_DOWN, // SLOPE_ONE | FLIP_H | |
|
|
0xffffffff, // SLOPE_ONE | FLIP_H | | FLIP_D
|
|
HW_X_ROUND_DOWN, // SLOPE_ONE | FLIP_H | FLIP_V |
|
|
0xffffffff // SLOPE_ONE | FLIP_H | FLIP_V | FLIP_D
|
|
};
|
|
|
|
//////////////////////////////////////////////////////////////////////////
|
|
// MGA specific defines
|
|
|
|
// The MGA's hardware can have 16 bits of significance for the error and
|
|
// step terms:
|
|
|
|
#define NUM_DDA_BITS 16
|
|
|
|
ULONG gaiSign[] = {
|
|
sdydxl_MAJOR_X | sdy_ADD | sdxl_ADD, // | | |
|
|
sdydxl_MAJOR_Y | sdy_ADD | sdxl_ADD, // | | |FLIP_D
|
|
sdydxl_MAJOR_X | sdy_SUB | sdxl_ADD, // | |FLIP_V|
|
|
sdydxl_MAJOR_Y | sdy_SUB | sdxl_ADD, // | |FLIP_V|FLIP_D
|
|
sdydxl_MAJOR_X | sdy_ADD | sdxl_SUB, // |FLIP_H| |
|
|
sdydxl_MAJOR_Y | sdy_ADD | sdxl_SUB, // |FLIP_H| |FLIP_D
|
|
sdydxl_MAJOR_X | sdy_SUB | sdxl_SUB, // |FLIP_H|FLIP_V|
|
|
sdydxl_MAJOR_Y | sdy_SUB | sdxl_SUB, // |FLIP_H|FLIP_V|FLIP_D
|
|
sdydxl_MAJOR_X | sdy_ADD | sdxl_ADD, // SLOPE_ONE| | |
|
|
0xffffffff, // SLOPE_ONE| | |FLIP_D
|
|
sdydxl_MAJOR_X | sdy_SUB | sdxl_ADD, // SLOPE_ONE| |FLIP_V|
|
|
0xffffffff, // SLOPE_ONE| |FLIP_V|FLIP_D
|
|
sdydxl_MAJOR_X | sdy_ADD | sdxl_SUB, // SLOPE_ONE|FLIP_H| |
|
|
0xffffffff, // SLOPE_ONE|FLIP_H| |FLIP_D
|
|
sdydxl_MAJOR_X | sdy_SUB | sdxl_SUB, // SLOPE_ONE|FLIP_H|FLIP_V|
|
|
0xffffffff // SLOPE_ONE|FLIP_H|FLIP_V|FLIP_D
|
|
};
|
|
|
|
/******************************Public*Routine******************************\
|
|
* BOOL bLinesComplex(ppdev, pptfxFirst, pptfxBuf, prun, cptfx, pls,
|
|
* prclClip, apfn[], flStart)
|
|
*
|
|
* Computes the DDA for the line and gets ready to draw it. Puts the
|
|
* pixel data into an array of strips, and calls a strip routine to
|
|
* do the actual drawing.
|
|
*
|
|
* Doing NT Lines Right
|
|
* --------------------
|
|
*
|
|
* In NT, all lines are given to the device driver in fractional
|
|
* coordinates, in a 28.4 fixed point format. The lower 4 bits are
|
|
* fractional for sub-pixel positioning.
|
|
*
|
|
* Note that you CANNOT! just round the coordinates to integers
|
|
* and pass the results to your favorite integer Bresenham routine!!
|
|
* (Unless, of course, you have such a high resolution device that
|
|
* nobody will notice -- not likely for a display device.) The
|
|
* fractions give a more accurate rendering of the line -- this is
|
|
* important for things like our Bezier curves, which would have 'kinks'
|
|
* if the points in its polyline approximation were rounded to integers.
|
|
*
|
|
* Unfortunately, for fractional lines there is more setup work to do
|
|
* a DDA than for integer lines. However, the main loop is exactly
|
|
* the same (and can be done entirely with 32 bit math).
|
|
*
|
|
* If You've Got Hardware That Does Bresenham
|
|
* ------------------------------------------
|
|
*
|
|
* A lot of hardware limits DDA error terms to 'n' bits. With fractional
|
|
* coordinates, 4 bits are given to the fractional part, letting
|
|
* you draw in hardware only those lines that lie entirely in a 2^(n-4)
|
|
* by 2^(n-4) pixel space.
|
|
*
|
|
* And you still have to correctly draw those lines with coordinates
|
|
* outside that space! Remember that the screen is only a viewport
|
|
* onto a 28.4 by 28.4 space -- if any part of the line is visible
|
|
* you MUST render it precisely, regardless of where the end points lie.
|
|
* So even if you do it in software, somewhere you'll have to have a
|
|
* 32 bit DDA routine.
|
|
*
|
|
* Our Implementation
|
|
* ------------------
|
|
*
|
|
* We employ a run length slice algorithm: our DDA calculates the
|
|
* number of pixels that are in each row (or 'strip') of pixels.
|
|
*
|
|
* We've separated the running of the DDA and the drawing of pixels:
|
|
* we run the DDA for several iterations and store the results in
|
|
* a 'strip' buffer (which are the lengths of consecutive pixel rows of
|
|
* the line), then we crank up a 'strip drawer' that will draw all the
|
|
* strips in the buffer.
|
|
*
|
|
* We also employ a 'half-flip' to reduce the number of strip
|
|
* iterations we need to do in the DDA and strip drawing loops: when a
|
|
* (normalized) line's slope is more than 1/2, we do a final flip
|
|
* about the line y = (1/2)x. So now, instead of each strip being
|
|
* consecutive horizontal or vertical pixel rows, each strip is composed
|
|
* of those pixels aligned in 45 degree rows. So a line like (0, 0) to
|
|
* (128, 128) would generate only one strip.
|
|
*
|
|
* We also always draw only left-to-right.
|
|
*
|
|
* Styled lines may have arbitrary style patterns. We specially
|
|
* optimize the default patterns (and call them 'masked' styles).
|
|
*
|
|
* The DDA Derivation
|
|
* ------------------
|
|
*
|
|
* Here is how I like to think of the DDA calculation.
|
|
*
|
|
* We employ Knuth's "diamond rule": rendering a one-pixel-wide line
|
|
* can be thought of as dragging a one-pixel-wide by one-pixel-high
|
|
* diamond along the true line. Pixel centers lie on the integer
|
|
* coordinates, and so we light any pixel whose center gets covered
|
|
* by the "drag" region (John D. Hobby, Journal of the Association
|
|
* for Computing Machinery, Vol. 36, No. 2, April 1989, pp. 209-229).
|
|
*
|
|
* We must define which pixel gets lit when the true line falls
|
|
* exactly half-way between two pixels. In this case, we follow
|
|
* the rule: when two pels are equidistant, the upper or left pel
|
|
* is illuminated, unless the slope is exactly one, in which case
|
|
* the upper or right pel is illuminated. (So we make the edges
|
|
* of the diamond exclusive, except for the top and left vertices,
|
|
* which are inclusive, unless we have slope one.)
|
|
*
|
|
* This metric decides what pixels should be on any line BEFORE it is
|
|
* flipped around for our calculation. Having a consistent metric
|
|
* this way will let our lines blend nicely with our curves. The
|
|
* metric also dictates that we will never have one pixel turned on
|
|
* directly above another that's turned on. We will also never have
|
|
* a gap; i.e., there will be exactly one pixel turned on for each
|
|
* column between the start and end points. All that remains to be
|
|
* done is to decide how many pixels should be turned on for each row.
|
|
*
|
|
* So lines we draw will consist of varying numbers of pixels on
|
|
* successive rows, for example:
|
|
*
|
|
* ******
|
|
* *****
|
|
* ******
|
|
* *****
|
|
*
|
|
* We'll call each set of pixels on a row a "strip".
|
|
*
|
|
* (Please remember that our coordinate space has the origin as the
|
|
* upper left pixel on the screen; postive y is down and positive x
|
|
* is right.)
|
|
*
|
|
* Device coordinates are specified as fixed point 28.4 numbers,
|
|
* where the first 28 bits are the integer coordinate, and the last
|
|
* 4 bits are the fraction. So coordinates may be thought of as
|
|
* having the form (x, y) = (M/F, N/F) where F is the constant scaling
|
|
* factor F = 2^4 = 16, and M and N are 32 bit integers.
|
|
*
|
|
* Consider the line from (M0/F, N0/F) to (M1/F, N1/F) which runs
|
|
* left-to-right and whose slope is in the first octant, and let
|
|
* dM = M1 - M0 and dN = N1 - N0. Then dM >= 0, dN >= 0 and dM >= dN.
|
|
*
|
|
* Since the slope of the line is less than 1, the edges of the
|
|
* drag region are created by the top and bottom vertices of the
|
|
* diamond. At any given pixel row y of the line, we light those
|
|
* pixels whose centers are between the left and right edges.
|
|
*
|
|
* Let mL(n) denote the line representing the left edge of the drag
|
|
* region. On pixel row j, the column of the first pixel to be
|
|
* lit is
|
|
*
|
|
* iL(j) = ceiling( mL(j * F) / F)
|
|
*
|
|
* Since the line's slope is less than one:
|
|
*
|
|
* iL(j) = ceiling( mL([j + 1/2] F) / F )
|
|
*
|
|
* Recall the formula for our line:
|
|
*
|
|
* n(m) = (dN / dM) (m - M0) + N0
|
|
*
|
|
* m(n) = (dM / dN) (n - N0) + M0
|
|
*
|
|
* Since the line's slope is less than one, the line representing
|
|
* the left edge of the drag region is the original line offset
|
|
* by 1/2 pixel in the y direction:
|
|
*
|
|
* mL(n) = (dM / dN) (n - F/2 - N0) + M0
|
|
*
|
|
* From this we can figure out the column of the first pixel that
|
|
* will be lit on row j, being careful of rounding (if the left
|
|
* edge lands exactly on an integer point, the pixel at that
|
|
* point is not lit because of our rounding convention):
|
|
*
|
|
* iL(j) = floor( mL(j F) / F ) + 1
|
|
*
|
|
* = floor( ((dM / dN) (j F - F/2 - N0) + M0) / F ) + 1
|
|
*
|
|
* = floor( F dM j - F/2 dM - N0 dM + dN M0) / F dN ) + 1
|
|
*
|
|
* F dM j - [ dM (N0 + F/2) - dN M0 ]
|
|
* = floor( ---------------------------------- ) + 1
|
|
* F dN
|
|
*
|
|
* dM j - [ dM (N0 + F/2) - dN M0 ] / F
|
|
* = floor( ------------------------------------ ) + 1 (1)
|
|
* dN
|
|
*
|
|
* = floor( (dM j + alpha) / dN ) + 1
|
|
*
|
|
* where
|
|
*
|
|
* alpha = - [ dM (N0 + F/2) - dN M0 ] / F
|
|
*
|
|
* We use equation (1) to calculate the DDA: there are iL(j+1) - iL(j)
|
|
* pixels in row j. Because we are always calculating iL(j) for
|
|
* integer quantities of j, we note that the only fractional term
|
|
* is constant, and so we can 'throw away' the fractional bits of
|
|
* alpha:
|
|
*
|
|
* beta = floor( - [ dM (N0 + F/2) - dN M0 ] / F ) (2)
|
|
*
|
|
* so
|
|
*
|
|
* iL(j) = floor( (dM j + beta) / dN ) + 1 (3)
|
|
*
|
|
* for integers j.
|
|
*
|
|
* Note if iR(j) is the line's rightmost pixel on row j, that
|
|
* iR(j) = iL(j + 1) - 1.
|
|
*
|
|
* Similarly, rewriting equation (1) as a function of column i,
|
|
* we can determine, given column i, on which pixel row j is the line
|
|
* lit:
|
|
*
|
|
* dN i + [ dM (N0 + F/2) - dN M0 ] / F
|
|
* j(i) = ceiling( ------------------------------------ ) - 1
|
|
* dM
|
|
*
|
|
* Floors are easier to compute, so we can rewrite this:
|
|
*
|
|
* dN i + [ dM (N0 + F/2) - dN M0 ] / F + dM - 1/F
|
|
* j(i) = floor( ----------------------------------------------- ) - 1
|
|
* dM
|
|
*
|
|
* dN i + [ dM (N0 + F/2) - dN M0 ] / F + dM - 1/F - dM
|
|
* = floor( ---------------------------------------------------- )
|
|
* dM
|
|
*
|
|
* dN i + [ dM (N0 + F/2) - dN M0 - 1 ] / F
|
|
* = floor( ---------------------------------------- )
|
|
* dM
|
|
*
|
|
* We can once again wave our hands and throw away the fractional bits
|
|
* of the remainder term:
|
|
*
|
|
* j(i) = floor( (dN i + gamma) / dM ) (4)
|
|
*
|
|
* where
|
|
*
|
|
* gamma = floor( [ dM (N0 + F/2) - dN M0 - 1 ] / F ) (5)
|
|
*
|
|
* We now note that
|
|
*
|
|
* beta = -gamma - 1 = ~gamma (6)
|
|
*
|
|
* To draw the pixels of the line, we could evaluate (3) on every scan
|
|
* line to determine where the strip starts. Of course, we don't want
|
|
* to do that because that would involve a multiply and divide for every
|
|
* scan. So we do everything incrementally.
|
|
*
|
|
* We would like to easily compute c , the number of pixels on scan j:
|
|
* j
|
|
*
|
|
* c = iL(j + 1) - iL(j)
|
|
* j
|
|
*
|
|
* = floor((dM (j + 1) + beta) / dN) - floor((dM j + beta) / dN) (7)
|
|
*
|
|
* This may be rewritten as
|
|
*
|
|
* c = floor(i + r / dN) - floor(i + r / dN) (8)
|
|
* j j+1 j+1 j j
|
|
*
|
|
* where i , i are integers and r < dN, r < dN.
|
|
* j j+1 j j+1
|
|
*
|
|
* Rewriting (7) again:
|
|
*
|
|
* c = floor(i + r / dN + dM / dN) - floor(i + r / dN)
|
|
* j j j j j
|
|
*
|
|
*
|
|
* = floor((r + dM) / dN) - floor(r / dN)
|
|
* j j
|
|
*
|
|
* This may be rewritten as
|
|
*
|
|
* c = dI + floor((r + dR) / dN) - floor(r / dN)
|
|
* j j j
|
|
*
|
|
* where dI + dR / dN = dM / dN, dI is an integer and dR < dN.
|
|
*
|
|
* r is the remainder (or "error") term in the DDA loop: r / dN
|
|
* j j
|
|
* is the exact fraction of a pixel at which the strip ends. To go
|
|
* on to the next scan and compute c we need to know r .
|
|
* j+1 j+1
|
|
*
|
|
* So in the main loop of the DDA:
|
|
*
|
|
* c = dI + floor((r + dR) / dN) and r = (r + dR) % dN
|
|
* j j j+1 j
|
|
*
|
|
* and we know r < dN, r < dN, and dR < dN.
|
|
* j j+1
|
|
*
|
|
* We have derived the DDA only for lines in the first octant; to
|
|
* handle other octants we do the common trick of flipping the line
|
|
* to the first octant by first making the line left-to-right by
|
|
* exchanging the end-points, then flipping about the lines y = 0 and
|
|
* y = x, as necessary. We must record the transformation so we can
|
|
* undo them later.
|
|
*
|
|
* We must also be careful of how the flips affect our rounding. If
|
|
* to get the line to the first octant we flipped about x = 0, we now
|
|
* have to be careful to round a y value of 1/2 up instead of down as
|
|
* we would for a line originally in the first octant (recall that
|
|
* "In the case where two pels are equidistant, the upper or left
|
|
* pel is illuminated...").
|
|
*
|
|
* To account for this rounding when running the DDA, we shift the line
|
|
* (or not) in the y direction by the smallest amount possible. That
|
|
* takes care of rounding for the DDA, but we still have to be careful
|
|
* about the rounding when determining the first and last pixels to be
|
|
* lit in the line.
|
|
*
|
|
* Determining The First And Last Pixels In The Line
|
|
* -------------------------------------------------
|
|
*
|
|
* Fractional coordinates also make it harder to determine which pixels
|
|
* will be the first and last ones in the line. We've already taken
|
|
* the fractional coordinates into account in calculating the DDA, but
|
|
* the DDA cannot tell us which are the end pixels because it is quite
|
|
* happy to calculate pixels on the line from minus infinity to positive
|
|
* infinity.
|
|
*
|
|
* The diamond rule determines the start and end pixels. (Recall that
|
|
* the sides are exclusive except for the left and top vertices.)
|
|
* This convention can be thought of in another way: there are diamonds
|
|
* around the pixels, and wherever the true line crosses a diamond,
|
|
* that pel is illuminated.
|
|
*
|
|
* Consider a line where we've done the flips to the first octant, and the
|
|
* floor of the start coordinates is the origin:
|
|
*
|
|
* +-----------------------> +x
|
|
* |
|
|
* | 0 1
|
|
* | 0123456789abcdef
|
|
* |
|
|
* | 0 00000000?1111111
|
|
* | 1 00000000 1111111
|
|
* | 2 0000000 111111
|
|
* | 3 000000 11111
|
|
* | 4 00000 ** 1111
|
|
* | 5 0000 ****1
|
|
* | 6 000 1***
|
|
* | 7 00 1 ****
|
|
* | 8 ? ***
|
|
* | 9 22 3 ****
|
|
* | a 222 33 ***
|
|
* | b 2222 333 ****
|
|
* | c 22222 3333 **
|
|
* | d 222222 33333
|
|
* | e 2222222 333333
|
|
* | f 22222222 3333333
|
|
* |
|
|
* | 2 3
|
|
* v
|
|
* +y
|
|
*
|
|
* If the start of the line lands on the diamond around pixel 0 (shown by
|
|
* the '0' region here), pixel 0 is the first pel in the line. The same
|
|
* is true for the other pels.
|
|
*
|
|
* A little more work has to be done if the line starts in the
|
|
* 'nether-land' between the diamonds (as illustrated by the '*' line):
|
|
* the first pel lit is the first diamond crossed by the line (pixel 1 in
|
|
* our example). This calculation is determined by the DDA or slope of
|
|
* the line.
|
|
*
|
|
* If the line starts exactly half way between two adjacent pixels
|
|
* (denoted here by the '?' spots), the first pixel is determined by our
|
|
* round-down convention (and is dependent on the flips done to
|
|
* normalize the line).
|
|
*
|
|
* Last Pel Exclusive
|
|
* ------------------
|
|
*
|
|
* To eliminate repeatedly lit pels between continuous connected lines,
|
|
* we employ a last-pel exclusive convention: if the line ends exactly on
|
|
* the diamond around a pel, that pel is not lit. (This eliminates the
|
|
* checks we had in the old code to see if we were re-lighting pels.)
|
|
*
|
|
* The Half Flip
|
|
* -------------
|
|
*
|
|
* To make our run length algorithm more efficient, we employ a "half
|
|
* flip". If after normalizing to the first octant, the slope is more
|
|
* than 1/2, we subtract the y coordinate from the x coordinate. This
|
|
* has the effect of reflecting the coordinates through the line of slope
|
|
* 1/2. Note that the diagonal gets mapped into the x-axis after a half
|
|
* flip.
|
|
*
|
|
* How Many Bits Do We Need, Anyway?
|
|
* ---------------------------------
|
|
*
|
|
* Note that if the line is visible on your screen, you must light up
|
|
* exactly the correct pixels, no matter where in the 28.4 x 28.4 device
|
|
* space the end points of the line lie (meaning you must handle 32 bit
|
|
* DDAs, you can certainly have optimized cases for lesser DDAs).
|
|
*
|
|
* We move the origin to (floor(M0 / F), floor(N0 / F)), so when we
|
|
* calculate gamma from (5), we know that 0 <= M0, N0 < F. And we
|
|
* are in the first octant, so dM >= dN. Then we know that gamma can
|
|
* be in the range [(-1/2)dM, (3/2)dM]. The DDI guarantees us that
|
|
* valid lines will have dM and dN values at most 31 bits (unsigned)
|
|
* of significance. So gamma requires 33 bits of significance (we store
|
|
* this as a 64 bit number for convenience).
|
|
*
|
|
* When running through the DDA loop, r + dR can have a value in the
|
|
* j
|
|
* range 0 <= r < 2 dN; thus the result must be a 32 bit unsigned value.
|
|
* j
|
|
*
|
|
* Testing Lines
|
|
* -------------
|
|
*
|
|
* To be NT compliant, a display driver must exactly adhere to GIQ,
|
|
* which means that for any given line, the driver must light exactly
|
|
* the same pels as does GDI. This can be tested using the Guiman tool
|
|
* provided elsewhere in the DDK, and 'ZTest', which draws random lines
|
|
* on the screen and to a bitmap, and compares the results.
|
|
*
|
|
* If You've Got Line Hardware
|
|
* ---------------------------
|
|
*
|
|
* If your hardware already adheres to GIQ, you're all set. Otherwise
|
|
* you'll want to look at the sample code and read the following:
|
|
*
|
|
* 1) You'll want to special case integer-only lines, since they require
|
|
* less processing time and are more common (CAD programs will probably
|
|
* only ever give integer lines). GDI does not provide a flag saying
|
|
* that all lines in a path are integer lines; consequently, you will
|
|
* have to explicitly check every line.
|
|
*
|
|
* 2) You are required to correctly draw any line in the 28.4 device
|
|
* space that intersects the viewport. If you have less than 32 bits
|
|
* of significance in the hardware for the Bresenham terms, extremely
|
|
* long lines would overflow the hardware. For such (rare) cases, you
|
|
* can fall back to strip-drawing code (or if your display is a frame
|
|
* buffer, fall back to the engine).
|
|
*
|
|
* 3) If you can explicitly set the Bresenham terms in your hardware, you
|
|
* can draw non-integer lines using the hardware. If your hardware has
|
|
* 'n' bits of precision, you can draw GIQ lines that are up to 2^(n-5)
|
|
* pels long (4 bits are required for the fractional part, and one bit is
|
|
* used as a sign bit). Note that integer lines don't require the 4
|
|
* fractional bits, so if you special case them as in 1), you can do
|
|
* integer lines that are up to 2^(n - 1) pels long. See the
|
|
* 'bHardwareLine' routine for an example.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
BOOL bLinesComplex(
|
|
PDEV* ppdev,
|
|
POINTFIX* pptfxFirst, // Start of first line
|
|
POINTFIX* pptfxBuf, // Pointer to buffer of all remaining lines
|
|
RUN* prun, // Pointer to runs if doing complex clipping
|
|
ULONG cptfx, // Number of points in pptfxBuf or number of runs
|
|
// in prun
|
|
LINESTATE* pls, // Colour and style info
|
|
RECTL* prclClip, // Pointer to clip rectangle if doing simple clipping
|
|
PFNSTRIP apfn[], // Array of strip functions
|
|
FLONG flStart) // Flags for each line, which is a combination of:
|
|
// FL_SIMPLE_CLIP
|
|
// FL_COMPLEX_CLIP
|
|
// FL_STYLED
|
|
// FL_LAST_PEL_INCLUSIVE
|
|
// - Should be set only for all integer lines,
|
|
// and can't be used with FL_COMPLEX_CLIP
|
|
{
|
|
ULONG M0;
|
|
ULONG dM;
|
|
ULONG N0;
|
|
ULONG dN;
|
|
ULONG dN_Original;
|
|
FLONG fl;
|
|
LONG x;
|
|
LONG y;
|
|
|
|
LONGLONG llBeta;
|
|
LONGLONG llGamma;
|
|
LONGLONG dl;
|
|
LONGLONG ll;
|
|
|
|
ULONG ulDelta;
|
|
|
|
ULONG x0;
|
|
ULONG y0;
|
|
ULONG x1;
|
|
ULONG cStylePels; // Major length of line in pixels for styling
|
|
ULONG xStart;
|
|
POINTL ptlStart;
|
|
STRIP strip;
|
|
PFNSTRIP pfn;
|
|
LONG cPels;
|
|
LONG* plStrip;
|
|
LONG* plStripEnd;
|
|
LONG cStripsInNextRun;
|
|
|
|
POINTFIX* pptfxBufEnd = pptfxBuf + cptfx; // Last point in path record
|
|
STYLEPOS spThis; // Style pos for this line
|
|
BYTE* pjBase;
|
|
|
|
pjBase = ppdev->pjBase;
|
|
|
|
do {
|
|
|
|
/***********************************************************************\
|
|
* Start the DDA calculations. *
|
|
\***********************************************************************/
|
|
|
|
M0 = (LONG) pptfxFirst->x;
|
|
dM = (LONG) pptfxBuf->x;
|
|
|
|
N0 = (LONG) pptfxFirst->y;
|
|
dN = (LONG) pptfxBuf->y;
|
|
|
|
fl = flStart;
|
|
|
|
// Check for non-clipped, non-styled integer endpoint lines
|
|
|
|
if ((fl & (FL_CLIP | FL_STYLED)) == 0)
|
|
{
|
|
// Integer end-point lines will probably account for 90% of
|
|
// all lines drawn (curves rendered by GDI will be an
|
|
// exception, and will have fractional GIQ coordinates).
|
|
//
|
|
// As such, we try to special-case integer lines as soon as
|
|
// possible.
|
|
//
|
|
// Unfortunately, the MGA's point-to-point line capability has
|
|
// a rounding convention for rendering tie-breaker pixels that
|
|
// doesn't match that of GDI's, so we can't use it for
|
|
// arbitrary integer lines, otherwise we would fail HCTs. But
|
|
// since horizontal and vertical lines have no tie-breakers,
|
|
// and probably account for 60% of all lines drawn, we special
|
|
// case them here. (The 'bHardwareLine' special case a little
|
|
// lower down will handle arbitrary direction lines.)
|
|
//
|
|
// Note: If your hardware can't handle GIQ lines ala
|
|
// 'bHardwareLine,' but can handle the correct rounding
|
|
// convention, I strongly recommend special-casing
|
|
// integer lines of arbitrary slope here, too.
|
|
//
|
|
// How can you tell if you have the correct rounding convention?
|
|
// Implement integer lines (they're easy), run Guiman and draw a
|
|
// bunch of Polyline lines in random directions, and then press
|
|
// the 'X' xor button -- if you see random pixels lit up, you've
|
|
// got the wrong convention...
|
|
|
|
if (((M0 | dM | N0 | dN) & (F - 1)) == 0)
|
|
{
|
|
// MGA specific code follows:
|
|
|
|
LONG x0;
|
|
LONG y0;
|
|
LONG x1;
|
|
LONG y1;
|
|
|
|
if (N0 == dN)
|
|
{
|
|
// Horizontal integer line:
|
|
|
|
y0 = (N0 >> FLOG2) + ppdev->yOffset;
|
|
x0 = (M0 >> FLOG2) + ppdev->xOffset;
|
|
x1 = (dM >> FLOG2) + ppdev->xOffset;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, 2);
|
|
CP_WRITE(pjBase, DWG_XYSTRT, PACKXY(x0, y0));
|
|
CP_START(pjBase, DWG_XYEND, PACKXY(x1, y0));
|
|
goto Next_Line;
|
|
}
|
|
else if (M0 == dM)
|
|
{
|
|
// Vertical integer line:
|
|
|
|
x0 = (M0 >> FLOG2) + ppdev->xOffset;
|
|
y0 = (N0 >> FLOG2) + ppdev->yOffset;
|
|
y1 = (dN >> FLOG2) + ppdev->yOffset;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, 2);
|
|
CP_WRITE(pjBase, DWG_XYSTRT, PACKXY(x0, y0));
|
|
CP_START(pjBase, DWG_XYEND, PACKXY(x0, y1));
|
|
goto Next_Line;
|
|
}
|
|
}
|
|
|
|
// Check for fractional endpoint lines that are small enough
|
|
// to use the hardware DDA:
|
|
|
|
if (bHardwareLine(ppdev, pptfxFirst, pptfxBuf))
|
|
goto Next_Line;
|
|
}
|
|
|
|
if ((LONG) M0 > (LONG) dM)
|
|
{
|
|
// Ensure that we run left-to-right:
|
|
|
|
register ULONG ulTmp;
|
|
SWAPL(M0, dM, ulTmp);
|
|
SWAPL(N0, dN, ulTmp);
|
|
fl |= FL_FLIP_H;
|
|
}
|
|
|
|
// Compute the delta dx. The DDI says we can never have a valid delta
|
|
// with a magnitued more than 2^31 - 1, but GDI never actually checks
|
|
// its transforms. So we have to check for this case to avoid overflow:
|
|
|
|
dM -= M0;
|
|
if ((LONG) dM < 0)
|
|
{
|
|
goto Next_Line;
|
|
}
|
|
|
|
if ((LONG) dN < (LONG) N0)
|
|
{
|
|
// Line runs from bottom to top, so flip across y = 0:
|
|
|
|
N0 = -(LONG) N0;
|
|
dN = -(LONG) dN;
|
|
fl |= FL_FLIP_V;
|
|
}
|
|
|
|
dN -= N0;
|
|
|
|
if ((LONG) dN < 0)
|
|
{
|
|
goto Next_Line;
|
|
}
|
|
|
|
// We now have a line running left-to-right, top-to-bottom from (M0, N0)
|
|
// to (M0 + dM, N0 + dN):
|
|
|
|
if (dN >= dM)
|
|
{
|
|
if (dN == dM)
|
|
{
|
|
// Have to special case slopes of one:
|
|
|
|
fl |= FL_FLIP_SLOPE_ONE;
|
|
}
|
|
else
|
|
{
|
|
// Since line has slope greater than 1, flip across x = y:
|
|
|
|
register ULONG ulTmp;
|
|
SWAPL(dM, dN, ulTmp);
|
|
SWAPL(M0, N0, ulTmp);
|
|
fl |= FL_FLIP_D;
|
|
}
|
|
}
|
|
|
|
fl |= gaflRound[(fl & FL_ROUND_MASK) >> FL_ROUND_SHIFT];
|
|
|
|
x = LFLOOR((LONG) M0);
|
|
y = LFLOOR((LONG) N0);
|
|
|
|
M0 = FXFRAC(M0);
|
|
N0 = FXFRAC(N0);
|
|
|
|
// Calculate the remainder term [ dM * (N0 + F/2) - M0 * dN ]:
|
|
|
|
llGamma = UInt32x32To64(dM, N0 + F/2) - UInt32x32To64(M0, dN);
|
|
if (fl & FL_V_ROUND_DOWN) // Adjust so y = 1/2 rounds down
|
|
{
|
|
llGamma--;
|
|
}
|
|
|
|
llGamma >>= FLOG2;
|
|
llBeta = ~llGamma;
|
|
|
|
/***********************************************************************\
|
|
* Figure out which pixels are at the ends of the line. *
|
|
\***********************************************************************/
|
|
|
|
// The toughest part of GIQ is determining the start and end pels.
|
|
//
|
|
// Our approach here is to calculate x0 and x1 (the inclusive start
|
|
// and end columns of the line respectively, relative to our normalized
|
|
// origin). Then x1 - x0 + 1 is the number of pels in the line. The
|
|
// start point is easily calculated by plugging x0 into our line equation
|
|
// (which takes care of whether y = 1/2 rounds up or down in value)
|
|
// getting y0, and then undoing the normalizing flips to get back
|
|
// into device space.
|
|
//
|
|
// We look at the fractional parts of the coordinates of the start and
|
|
// end points, and call them (M0, N0) and (M1, N1) respectively, where
|
|
// 0 <= M0, N0, M1, N1 < 16. We plot (M0, N0) on the following grid
|
|
// to determine x0:
|
|
//
|
|
// +-----------------------> +x
|
|
// |
|
|
// | 0 1
|
|
// | 0123456789abcdef
|
|
// |
|
|
// | 0 ........?xxxxxxx
|
|
// | 1 ..........xxxxxx
|
|
// | 2 ...........xxxxx
|
|
// | 3 ............xxxx
|
|
// | 4 .............xxx
|
|
// | 5 ..............xx
|
|
// | 6 ...............x
|
|
// | 7 ................
|
|
// | 8 ................
|
|
// | 9 ......**........
|
|
// | a ........****...x
|
|
// | b ............****
|
|
// | c .............xxx****
|
|
// | d ............xxxx ****
|
|
// | e ...........xxxxx ****
|
|
// | f ..........xxxxxx
|
|
// |
|
|
// | 2 3
|
|
// v
|
|
//
|
|
// +y
|
|
//
|
|
// This grid accounts for the appropriate rounding of GIQ and last-pel
|
|
// exclusion. If (M0, N0) lands on an 'x', x0 = 2. If (M0, N0) lands
|
|
// on a '.', x0 = 1. If (M0, N0) lands on a '?', x0 rounds up or down,
|
|
// depending on what flips have been done to normalize the line.
|
|
//
|
|
// For the end point, if (M1, N1) lands on an 'x', x1 =
|
|
// floor((M0 + dM) / 16) + 1. If (M1, N1) lands on a '.', x1 =
|
|
// floor((M0 + dM)). If (M1, N1) lands on a '?', x1 rounds up or down,
|
|
// depending on what flips have been done to normalize the line.
|
|
//
|
|
// Lines of exactly slope one require a special case for both the start
|
|
// and end. For example, if the line ends such that (M1, N1) is (9, 1),
|
|
// the line has gone exactly through (8, 0) -- which may be considered
|
|
// to be part of 'x' because of rounding! So slopes of exactly slope
|
|
// one going through (8, 0) must also be considered as belonging in 'x'.
|
|
//
|
|
// For lines that go left-to-right, we have the following grid:
|
|
//
|
|
// +-----------------------> +x
|
|
// |
|
|
// | 0 1
|
|
// | 0123456789abcdef
|
|
// |
|
|
// | 0 xxxxxxxx?.......
|
|
// | 1 xxxxxxx.........
|
|
// | 2 xxxxxx..........
|
|
// | 3 xxxxx...........
|
|
// | 4 xxxx............
|
|
// | 5 xxx.............
|
|
// | 6 xx..............
|
|
// | 7 x...............
|
|
// | 8 x...............
|
|
// | 9 x.....**........
|
|
// | a xx......****....
|
|
// | b xxx.........****
|
|
// | c xxxx............****
|
|
// | d xxxxx........... ****
|
|
// | e xxxxxx.......... ****
|
|
// | f xxxxxxx.........
|
|
// |
|
|
// | 2 3
|
|
// v
|
|
//
|
|
// +y
|
|
//
|
|
// This grid accounts for the appropriate rounding of GIQ and last-pel
|
|
// exclusion. If (M0, N0) lands on an 'x', x0 = 0. If (M0, N0) lands
|
|
// on a '.', x0 = 1. If (M0, N0) lands on a '?', x0 rounds up or down,
|
|
// depending on what flips have been done to normalize the line.
|
|
//
|
|
// For the end point, if (M1, N1) lands on an 'x', x1 =
|
|
// floor((M0 + dM) / 16) - 1. If (M1, N1) lands on a '.', x1 =
|
|
// floor((M0 + dM)). If (M1, N1) lands on a '?', x1 rounds up or down,
|
|
// depending on what flips have been done to normalize the line.
|
|
//
|
|
// Lines of exactly slope one must be handled similarly to the right-to-
|
|
// left case.
|
|
|
|
{
|
|
|
|
// Calculate x0, x1
|
|
|
|
ULONG N1 = FXFRAC(N0 + dN);
|
|
ULONG M1 = FXFRAC(M0 + dM);
|
|
|
|
x1 = LFLOOR(M0 + dM);
|
|
|
|
if (fl & FL_LAST_PEL_INCLUSIVE)
|
|
{
|
|
// It sure is easy to compute the first pel when lines have only
|
|
// integer coordinates and are last-pel inclusive:
|
|
|
|
x0 = 0;
|
|
y0 = 0;
|
|
|
|
// Last-pel inclusive lines that are exactly one pixel long
|
|
// have a 'delta-x' and 'delta-y' equal to zero. The problem is
|
|
// that our clip code assumes that 'delta-x' is always non-zero
|
|
// (since it never happens with last-pel exclusive lines). As
|
|
// an inelegant solution, we simply modify 'delta-x' in this
|
|
// case -- because the line is exactly one pixel long, changing
|
|
// the slope will obviously have no effect on rasterization.
|
|
|
|
if (x1 == 0)
|
|
{
|
|
dM = 1;
|
|
llGamma = 0;
|
|
llBeta = ~llGamma;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (fl & FL_FLIP_H)
|
|
{
|
|
// ---------------------------------------------------------------
|
|
// Line runs right-to-left: <----
|
|
|
|
// Compute x1:
|
|
|
|
if (N1 == 0)
|
|
{
|
|
if (LROUND(M1, fl & FL_H_ROUND_DOWN))
|
|
{
|
|
x1++;
|
|
}
|
|
}
|
|
else if (abs((LONG) (N1 - F/2)) + M1 > F)
|
|
{
|
|
x1++;
|
|
}
|
|
|
|
if ((fl & (FL_FLIP_SLOPE_ONE | FL_H_ROUND_DOWN))
|
|
== (FL_FLIP_SLOPE_ONE))
|
|
{
|
|
// Have to special-case diagonal lines going through our
|
|
// the point exactly equidistant between two horizontal
|
|
// pixels, if we're supposed to round x=1/2 down:
|
|
|
|
if ((N1 > 0) && (M1 == N1 + 8))
|
|
x1++;
|
|
|
|
// Don't you love special cases? Is this a rhetorical question?
|
|
|
|
if ((N0 > 0) && (M0 == N0 + 8))
|
|
{
|
|
x0 = 2;
|
|
ulDelta = dN;
|
|
goto right_to_left_compute_y0;
|
|
}
|
|
}
|
|
|
|
// Compute x0:
|
|
|
|
x0 = 1;
|
|
ulDelta = 0;
|
|
if (N0 == 0)
|
|
{
|
|
if (LROUND(M0, fl & FL_H_ROUND_DOWN))
|
|
{
|
|
x0 = 2;
|
|
ulDelta = dN;
|
|
}
|
|
}
|
|
else if (abs((LONG) (N0 - F/2)) + M0 > F)
|
|
{
|
|
x0 = 2;
|
|
ulDelta = dN;
|
|
}
|
|
|
|
|
|
// Compute y0:
|
|
|
|
right_to_left_compute_y0:
|
|
|
|
y0 = 0;
|
|
ll = llGamma + (LONGLONG) ulDelta;
|
|
|
|
if (ll >= (LONGLONG) (2 * dM - dN))
|
|
y0 = 2;
|
|
else if (ll >= (LONGLONG) (dM - dN))
|
|
y0 = 1;
|
|
}
|
|
else
|
|
{
|
|
// ---------------------------------------------------------------
|
|
// Line runs left-to-right: ---->
|
|
|
|
// Compute x1:
|
|
|
|
if (!(fl & FL_LAST_PEL_INCLUSIVE))
|
|
x1--;
|
|
|
|
if (M1 > 0)
|
|
{
|
|
if (N1 == 0)
|
|
{
|
|
if (LROUND(M1, fl & FL_H_ROUND_DOWN))
|
|
x1++;
|
|
}
|
|
else if (abs((LONG) (N1 - F/2)) <= (LONG) M1)
|
|
{
|
|
x1++;
|
|
}
|
|
}
|
|
|
|
if ((fl & (FL_FLIP_SLOPE_ONE | FL_H_ROUND_DOWN))
|
|
== (FL_FLIP_SLOPE_ONE | FL_H_ROUND_DOWN))
|
|
{
|
|
// Have to special-case diagonal lines going through our
|
|
// the point exactly equidistant between two horizontal
|
|
// pixels, if we're supposed to round x=1/2 down:
|
|
|
|
if ((M1 > 0) && (N1 == M1 + 8))
|
|
x1--;
|
|
|
|
if ((M0 > 0) && (N0 == M0 + 8))
|
|
{
|
|
x0 = 0;
|
|
goto left_to_right_compute_y0;
|
|
}
|
|
}
|
|
|
|
// Compute x0:
|
|
|
|
x0 = 0;
|
|
if (M0 > 0)
|
|
{
|
|
if (N0 == 0)
|
|
{
|
|
if (LROUND(M0, fl & FL_H_ROUND_DOWN))
|
|
x0 = 1;
|
|
}
|
|
else if (abs((LONG) (N0 - F/2)) <= (LONG) M0)
|
|
{
|
|
x0 = 1;
|
|
}
|
|
}
|
|
|
|
// Compute y0:
|
|
|
|
left_to_right_compute_y0:
|
|
|
|
y0 = 0;
|
|
if (llGamma >= (LONGLONG) (dM - (dN & (-(LONG) x0))))
|
|
{
|
|
y0 = 1;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
cStylePels = x1 - x0 + 1;
|
|
if ((LONG) cStylePels <= 0)
|
|
goto Next_Line;
|
|
|
|
xStart = x0;
|
|
|
|
/***********************************************************************\
|
|
* Complex clipping. *
|
|
\***********************************************************************/
|
|
|
|
if (fl & FL_COMPLEX_CLIP)
|
|
{
|
|
dN_Original = dN;
|
|
|
|
Continue_Complex_Clipping:
|
|
|
|
if (fl & FL_FLIP_H)
|
|
{
|
|
// Line runs right-to-left <-----
|
|
|
|
x0 = xStart + cStylePels - prun->iStop - 1;
|
|
x1 = xStart + cStylePels - prun->iStart - 1;
|
|
}
|
|
else
|
|
{
|
|
// Line runs left-to-right ----->
|
|
|
|
x0 = xStart + prun->iStart;
|
|
x1 = xStart + prun->iStop;
|
|
}
|
|
|
|
prun++;
|
|
|
|
// Reset some variables we'll nuke a little later:
|
|
|
|
dN = dN_Original;
|
|
pls->spNext = pls->spComplex;
|
|
|
|
// No overflow since large integer math is used. Both values
|
|
// will be positive:
|
|
|
|
dl = UInt32x32To64(x0, dN) + llGamma;
|
|
|
|
// y0 = dl / dM:
|
|
|
|
y0 = UInt64Div32To32(dl, dM);
|
|
|
|
ASSERTDD((LONG) y0 >= 0, "y0 weird: Goofed up end pel calc?");
|
|
}
|
|
|
|
/***********************************************************************\
|
|
* Simple rectangular clipping. *
|
|
\***********************************************************************/
|
|
|
|
if (fl & FL_SIMPLE_CLIP)
|
|
{
|
|
ULONG y1;
|
|
LONG xRight;
|
|
LONG xLeft;
|
|
LONG yBottom;
|
|
LONG yTop;
|
|
|
|
// Note that y0 and y1 are actually the lower and upper bounds,
|
|
// respectively, of the y coordinates of the line (the line may
|
|
// have actually shrunk due to first/last pel clipping).
|
|
//
|
|
// Also note that x0, y0 are not necessarily zero.
|
|
|
|
RECTL* prcl = &prclClip[(fl & FL_RECTLCLIP_MASK) >>
|
|
FL_RECTLCLIP_SHIFT];
|
|
|
|
// Normalize to the same point we've normalized for the DDA
|
|
// calculations:
|
|
|
|
xRight = prcl->right - x;
|
|
xLeft = prcl->left - x;
|
|
yBottom = prcl->bottom - y;
|
|
yTop = prcl->top - y;
|
|
|
|
if (yBottom <= (LONG) y0 ||
|
|
xRight <= (LONG) x0 ||
|
|
xLeft > (LONG) x1)
|
|
{
|
|
Totally_Clipped:
|
|
|
|
if (fl & FL_STYLED)
|
|
{
|
|
pls->spNext += cStylePels;
|
|
if (pls->spNext >= pls->spTotal2)
|
|
pls->spNext %= pls->spTotal2;
|
|
}
|
|
|
|
goto Next_Line;
|
|
}
|
|
|
|
if ((LONG) x1 >= xRight)
|
|
x1 = xRight - 1;
|
|
|
|
// We have to know the correct y1, which we haven't bothered to
|
|
// calculate up until now. This multiply and divide is quite
|
|
// expensive; we could replace it with code similar to that which
|
|
// we used for computing y0.
|
|
//
|
|
// The reason why we need the actual value, and not an upper
|
|
// bounds guess like y1 = LFLOOR(dM) + 2 is that we have to be
|
|
// careful when calculating x(y) that y0 <= y <= y1, otherwise
|
|
// we can overflow on the divide (which, needless to say, is very
|
|
// bad).
|
|
|
|
dl = UInt32x32To64(x1, dN) + llGamma;
|
|
|
|
// y1 = dl / dM:
|
|
|
|
y1 = UInt64Div32To32(dl, dM);
|
|
|
|
if (yTop > (LONG) y1)
|
|
goto Totally_Clipped;
|
|
|
|
if (yBottom <= (LONG) y1)
|
|
{
|
|
y1 = yBottom;
|
|
dl = UInt32x32To64(y1, dM) + llBeta;
|
|
|
|
// x1 = dl / dN:
|
|
|
|
x1 = UInt64Div32To32(dl, dN);
|
|
}
|
|
|
|
// At this point, we've taken care of calculating the intercepts
|
|
// with the right and bottom edges. Now we work on the left and
|
|
// top edges:
|
|
|
|
if (xLeft > (LONG) x0)
|
|
{
|
|
x0 = xLeft;
|
|
dl = UInt32x32To64(x0, dN) + llGamma;
|
|
|
|
// y0 = dl / dM;
|
|
|
|
y0 = UInt64Div32To32(dl, dM);
|
|
|
|
if (yBottom <= (LONG) y0)
|
|
goto Totally_Clipped;
|
|
}
|
|
|
|
if (yTop > (LONG) y0)
|
|
{
|
|
y0 = yTop;
|
|
dl = UInt32x32To64(y0, dM) + llBeta;
|
|
|
|
// x0 = dl / dN + 1;
|
|
|
|
x0 = UInt64Div32To32(dl, dN) + 1;
|
|
|
|
if (xRight <= (LONG) x0)
|
|
goto Totally_Clipped;
|
|
}
|
|
|
|
ASSERTDD(x0 <= x1, "Improper rectangle clip");
|
|
}
|
|
|
|
/***********************************************************************\
|
|
* Done clipping. Unflip if necessary. *
|
|
\***********************************************************************/
|
|
|
|
ptlStart.x = x + x0;
|
|
ptlStart.y = y + y0;
|
|
|
|
if (fl & FL_FLIP_D)
|
|
{
|
|
register LONG lTmp;
|
|
SWAPL(ptlStart.x, ptlStart.y, lTmp);
|
|
}
|
|
|
|
|
|
if (fl & FL_FLIP_V)
|
|
{
|
|
ptlStart.y = -ptlStart.y;
|
|
}
|
|
|
|
cPels = x1 - x0 + 1;
|
|
|
|
/***********************************************************************\
|
|
* Style calculations. *
|
|
\***********************************************************************/
|
|
|
|
if (fl & FL_STYLED)
|
|
{
|
|
STYLEPOS sp;
|
|
|
|
spThis = pls->spNext;
|
|
pls->spNext += cStylePels;
|
|
|
|
{
|
|
if (pls->spNext >= pls->spTotal2)
|
|
pls->spNext %= pls->spTotal2;
|
|
|
|
if (fl & FL_FLIP_H)
|
|
sp = pls->spNext - x0 + xStart;
|
|
else
|
|
sp = spThis + x0 - xStart;
|
|
|
|
ASSERTDD(fl & FL_STYLED, "Oops");
|
|
|
|
// Normalize our target style position:
|
|
|
|
if ((sp < 0) || (sp >= pls->spTotal2))
|
|
{
|
|
sp %= pls->spTotal2;
|
|
|
|
// The modulus of a negative number is not well-defined
|
|
// in C -- if it's negative we'll adjust it so that it's
|
|
// back in the range [0, spTotal2):
|
|
|
|
if (sp < 0)
|
|
sp += pls->spTotal2;
|
|
}
|
|
|
|
// Since we always draw the line left-to-right, but styling is
|
|
// always done in the direction of the original line, we have
|
|
// to figure out where we are in the style array for the left
|
|
// edge of this line.
|
|
|
|
if (fl & FL_FLIP_H)
|
|
{
|
|
// Line originally ran right-to-left:
|
|
|
|
sp = -sp;
|
|
if (sp < 0)
|
|
sp += pls->spTotal2;
|
|
|
|
pls->ulStyleMask = ~pls->ulStartMask;
|
|
pls->pspStart = &pls->aspRtoL[0];
|
|
pls->pspEnd = &pls->aspRtoL[pls->cStyle - 1];
|
|
}
|
|
else
|
|
{
|
|
// Line originally ran left-to-right:
|
|
|
|
pls->ulStyleMask = pls->ulStartMask;
|
|
pls->pspStart = &pls->aspLtoR[0];
|
|
pls->pspEnd = &pls->aspLtoR[pls->cStyle - 1];
|
|
}
|
|
|
|
if (sp >= pls->spTotal)
|
|
{
|
|
sp -= pls->spTotal;
|
|
if (pls->cStyle & 1)
|
|
pls->ulStyleMask = ~pls->ulStyleMask;
|
|
}
|
|
|
|
pls->psp = pls->pspStart;
|
|
while (sp >= *pls->psp)
|
|
sp -= *pls->psp++;
|
|
|
|
ASSERTDD(pls->psp <= pls->pspEnd,
|
|
"Flew off into NeverNeverLand");
|
|
|
|
pls->spRemaining = *pls->psp - sp;
|
|
if ((pls->psp - pls->pspStart) & 1)
|
|
pls->ulStyleMask = ~pls->ulStyleMask;
|
|
}
|
|
}
|
|
|
|
plStrip = &strip.alStrips[0];
|
|
plStripEnd = &strip.alStrips[STRIP_MAX]; // Is exclusive
|
|
cStripsInNextRun = 0x7fffffff;
|
|
|
|
strip.ptlStart = ptlStart;
|
|
|
|
if (2 * dN > dM &&
|
|
!(fl & FL_STYLED))
|
|
{
|
|
// Do a half flip! Remember that we may doing this on the
|
|
// same line multiple times for complex clipping (meaning the
|
|
// affected variables should be reset for every clip run):
|
|
|
|
fl |= FL_FLIP_HALF;
|
|
|
|
llBeta = llGamma - (LONGLONG) ((LONG) dM);
|
|
dN = dM - dN;
|
|
y0 = x0 - y0; // Note this may overflow, but that's okay
|
|
}
|
|
|
|
// Now, run the DDA starting at (ptlStart.x, ptlStart.y)!
|
|
|
|
strip.flFlips = fl;
|
|
pfn = apfn[(fl & FL_STRIP_MASK) >> FL_STRIP_SHIFT];
|
|
|
|
// Now calculate the DDA variables needed to figure out how many pixels
|
|
// go in the very first strip:
|
|
|
|
{
|
|
register LONG i;
|
|
register ULONG dI;
|
|
register ULONG dR;
|
|
ULONG r;
|
|
|
|
if (dN == 0)
|
|
i = 0x7fffffff;
|
|
else
|
|
{
|
|
dl = UInt32x32To64(y0 + 1, dM) + llBeta;
|
|
|
|
ASSERTDD(dl >= 0, "Oops!");
|
|
|
|
// i = (dl / dN) - x0 + 1;
|
|
// r = (dl % dN);
|
|
|
|
i = UInt64Div32To32(dl, dN);
|
|
r = UInt64Mod32To32(dl, dN);
|
|
i = i - x0 + 1;
|
|
|
|
dI = dM / dN;
|
|
dR = dM % dN; // 0 <= dR < dN
|
|
|
|
ASSERTDD(dI > 0, "Weird dI");
|
|
}
|
|
|
|
ASSERTDD(i > 0 && i <= 0x7fffffff, "Weird initial strip length");
|
|
ASSERTDD(cPels > 0, "Zero pel line");
|
|
|
|
/***********************************************************************\
|
|
* Run the DDA! *
|
|
\***********************************************************************/
|
|
|
|
while(TRUE)
|
|
{
|
|
cPels -= i;
|
|
if (cPels <= 0)
|
|
break;
|
|
|
|
*plStrip++ = i;
|
|
|
|
if (plStrip == plStripEnd)
|
|
{
|
|
strip.cStrips = (LONG)(plStrip - &strip.alStrips[0]);
|
|
(*pfn)(ppdev, &strip, pls);
|
|
plStrip = &strip.alStrips[0];
|
|
}
|
|
|
|
i = dI;
|
|
r += dR;
|
|
|
|
if (r >= dN)
|
|
{
|
|
r -= dN;
|
|
i++;
|
|
}
|
|
}
|
|
|
|
*plStrip++ = cPels + i;
|
|
|
|
strip.cStrips = (LONG)(plStrip - &strip.alStrips[0]);
|
|
(*pfn)(ppdev, &strip, pls);
|
|
}
|
|
|
|
Next_Line:
|
|
|
|
if (fl & FL_COMPLEX_CLIP)
|
|
{
|
|
cptfx--;
|
|
if (cptfx != 0)
|
|
goto Continue_Complex_Clipping;
|
|
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
pptfxFirst = pptfxBuf;
|
|
pptfxBuf++;
|
|
}
|
|
|
|
} while (pptfxBuf < pptfxBufEnd);
|
|
|
|
return(TRUE);
|
|
}
|
|
|
|
/******************************Public*Routine******************************\
|
|
* VOID vLinesSimple
|
|
*
|
|
* Historically, NT has used funky 'GIQ' coordinates that have 4 bits of
|
|
* fraction, and is very picky about which pixels are lit even for lines
|
|
* whose coordinates are all integers. But as of NT 4.0 Service-Pack 1,
|
|
* NT now informs us when all the coordinates in a path are integers (via
|
|
* the PO_ALL_INTEGERS flag), and what's more it allows us to request that
|
|
* the path coordinates before returned as integers instead of the funky
|
|
* 28.4 (by setting the PO_ENUM_AS_INTEGERS flag).
|
|
*
|
|
* But the best part is that GDI now allows us to choose which pixel we'll
|
|
* light for tie-breaker cases, when the error term is exactly 0.5 (the
|
|
* lines must still be last-pixel exclusive, of course).
|
|
*
|
|
* So we can now use the hardware's auto-Bresenham-setup (point-to-point
|
|
* lines) capability! And that's exactly what we do here...
|
|
*
|
|
* Unfortunately, this code is complicated by the funky format for the MGA's
|
|
* auto-line mechanism -- we have to send down batches composed of a 1 dword
|
|
* flag, followed by 32 vertices. The dword flag indicates which of the
|
|
* following vertices should be considered the disjoint from the rest (i.e.,
|
|
* indicates PD_BEGINSUBPATH to the hardware).
|
|
*
|
|
\**************************************************************************/
|
|
|
|
// !!! These defines should be retrieved from winddi.h
|
|
|
|
#define PO_ALL_INTEGERS 0x00000004
|
|
#define PO_ENUM_AS_INTEGERS 0x00000008
|
|
|
|
#define VECTOR_WRITE_ON(ppdev, pjBase, ulOpmodeOut) \
|
|
{ \
|
|
ulOpmodeOut = CP_READ_REGISTER(pjBase + HST_OPMODE) & OPMODE_OTHER_INFO; \
|
|
CP_WRITE_DIRECT_BYTE(pjBase, HST_OPMODE, ulOpmodeOut | (dmamod_VECTOR_WRITE)); \
|
|
CP_MEMORY_BARRIER(); \
|
|
CP_WRITE_DIRECT_BYTE(pjBase, HST_OPMODE, ulOpmodeOut | (dmamod_VECTOR_WRITE | pseudodma_ON)); \
|
|
CP_EIEIO(); \
|
|
CP_READ_REGISTER(pjBase + HST_OPMODE); \
|
|
}
|
|
|
|
#define VECTOR_WRITE_OFF(ppdev, pjBase, ulOpmodeIn) \
|
|
{ \
|
|
CP_WRITE_DIRECT_BYTE(pjBase, HST_OPMODE, ulOpmodeIn | (pseudodma_OFF)); \
|
|
CP_EIEIO(); \
|
|
}
|
|
|
|
// To use the MGA's pseudo-DMA vector transfer, we have to do everything
|
|
// in batches of one dword 'tag' followed by 32 vertices:
|
|
|
|
#define VECTOR_BATCH_SIZE 32
|
|
|
|
VOID vLinesSimple(
|
|
PDEV* ppdev,
|
|
PATHOBJ* ppo)
|
|
{
|
|
BYTE* pjBase;
|
|
BYTE* pjDma;
|
|
ULONG* pulDma;
|
|
LONG xOffset;
|
|
LONG yOffset;
|
|
BOOL bMore;
|
|
PATHDATA pd;
|
|
LONG cLines;
|
|
POINTFIX* pptfx;
|
|
POINTFIX ptfxStartFigure;
|
|
ULONG axyBuf[VECTOR_BATCH_SIZE];
|
|
ULONG* pxy;
|
|
LONG cxy;
|
|
ULONG ulTag;
|
|
ULONG ulOpmode;
|
|
|
|
// Notify GDI that we want the path enumerated as integers instead of
|
|
// fixed coordinates. Note that we can only do this when GDI has set
|
|
// the PO_ALL_INTEGERS flag:
|
|
|
|
ppo->fl |= PO_ENUM_AS_INTEGERS;
|
|
|
|
pjBase = ppdev->pjBase;
|
|
pjDma = pjBase + DMAWND;
|
|
xOffset = ppdev->xOffset;
|
|
yOffset = ppdev->yOffset;
|
|
|
|
pxy = axyBuf;
|
|
cxy = VECTOR_BATCH_SIZE;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, FIFOSIZE);
|
|
VECTOR_WRITE_ON(ppdev, pjBase, ulOpmode);
|
|
|
|
do {
|
|
bMore = PATHOBJ_bEnum(ppo, &pd);
|
|
cLines = pd.count;
|
|
pptfx = pd.pptfx;
|
|
|
|
if (pd.flags & PD_BEGINSUBPATH)
|
|
{
|
|
cLines--;
|
|
ptfxStartFigure.x = pptfx->x;
|
|
ptfxStartFigure.y = pptfx->y;
|
|
|
|
*pxy = PACKXY(pptfx->x + xOffset, pptfx->y + yOffset);
|
|
pxy++;
|
|
pptfx++;
|
|
|
|
// Set the high bit to zero, and move all the other bits down:
|
|
|
|
ulTag >>= 1;
|
|
|
|
if (--cxy == 0)
|
|
{
|
|
// Flush the buffer!
|
|
|
|
pxy = axyBuf;
|
|
cxy = VECTOR_BATCH_SIZE;
|
|
pulDma = (ULONG*) pjDma;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, 1);
|
|
CP_WRITE_DMA(ppdev, pulDma, ulTag);
|
|
pulDma++;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, FIFOSIZE);
|
|
do {
|
|
CP_WRITE_DMA(ppdev, pulDma, *pxy);
|
|
pulDma++;
|
|
pxy++;
|
|
|
|
} while (--cxy != 0);
|
|
|
|
pxy = axyBuf;
|
|
cxy = VECTOR_BATCH_SIZE;
|
|
}
|
|
}
|
|
|
|
PolylineSegments:
|
|
|
|
while (cLines-- > 0)
|
|
{
|
|
*pxy = PACKXY(pptfx->x + xOffset, pptfx->y + yOffset);
|
|
pxy++;
|
|
pptfx++;
|
|
|
|
// Set the high bit to one, and move all the other bits down:
|
|
|
|
ulTag = 0x80000000 | (ulTag >> 1);
|
|
|
|
if (--cxy == 0)
|
|
{
|
|
// Flush the buffer!
|
|
|
|
pxy = axyBuf;
|
|
cxy = VECTOR_BATCH_SIZE;
|
|
pulDma = (ULONG*) pjDma;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, 1);
|
|
CP_WRITE_DMA(ppdev, pulDma, ulTag);
|
|
pulDma++;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, FIFOSIZE);
|
|
do {
|
|
CP_WRITE_DMA(ppdev, pulDma, *pxy);
|
|
pulDma++;
|
|
pxy++;
|
|
|
|
} while (--cxy != 0);
|
|
|
|
pxy = axyBuf;
|
|
cxy = VECTOR_BATCH_SIZE;
|
|
}
|
|
}
|
|
|
|
if (pd.flags & PD_CLOSEFIGURE)
|
|
{
|
|
pd.flags &= ~PD_CLOSEFIGURE;
|
|
pptfx = &ptfxStartFigure;
|
|
goto PolylineSegments;
|
|
}
|
|
|
|
} while (bMore);
|
|
|
|
// Flush the buffer if there's anything left:
|
|
|
|
if (cxy != VECTOR_BATCH_SIZE)
|
|
{
|
|
ulTag >>= cxy;
|
|
pxy = axyBuf;
|
|
cxy = VECTOR_BATCH_SIZE - cxy;
|
|
pulDma = (ULONG*) pjDma;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, 1);
|
|
CP_WRITE_DMA(ppdev, pulDma, ulTag);
|
|
pulDma++;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, cxy);
|
|
do {
|
|
CP_WRITE_DMA(ppdev, pulDma, *pxy);
|
|
pulDma++;
|
|
pxy++;
|
|
|
|
} while (--cxy != 0);
|
|
}
|
|
|
|
VECTOR_WRITE_OFF(ppdev, pjBase, ulOpmode);
|
|
}
|
|
|
|
/******************************Public*Routine******************************\
|
|
* BOOL bHardwareLine(ppdev, pptfxStart, pptfxEnd)
|
|
*
|
|
* This routine is useful for folks who have line drawing hardware where
|
|
* they can explicitly set the Bresenham terms -- they can use this routine
|
|
* to draw fractional coordinate GIQ lines with the hardware.
|
|
*
|
|
* Fractional coordinate lines require an extra 4 bits of precision in the
|
|
* Bresenham terms. For example, if your hardware has 13 bits of precision
|
|
* for the terms, you can only draw GIQ lines up to 255 pels long using this
|
|
* routine.
|
|
*
|
|
* Input:
|
|
* pptfxStart - Points to GIQ coordinate of start of line
|
|
* pptfxEnd - Points to GIQ coordinate of end of line
|
|
* NUM_DDA_BITS- The number of bits of precision your hardware can support.
|
|
*
|
|
* Output:
|
|
* returns - TRUE if the line was drawn.
|
|
* FALSE if the line is too long, and the strips code must be
|
|
* used.
|
|
*
|
|
* DDALINE:
|
|
* iDir - Direction of the line, as an octant numbered as follows:
|
|
*
|
|
* \ 5 | 6 /
|
|
* \ | /
|
|
* 4 \ | / 7
|
|
* \ /
|
|
* -----+-----
|
|
* /|\
|
|
* 3 / | \ 0
|
|
* / | \
|
|
* / 2 | 1 \
|
|
*
|
|
* ptlStart - Start pixel of line.
|
|
* cPels - # of pels in line. *NOTE* You must check if this is <= 0!
|
|
* dMajor - Major axis delta.
|
|
* dMinor - Minor axis delta.
|
|
* lErrorTerm - Error term.
|
|
*
|
|
* What you do with the last 3 terms may be a little tricky. They are
|
|
* actually the terms for the formula of the normalized line
|
|
*
|
|
* dMinor * x + (lErrorTerm + dMajor)
|
|
* y(x) = floor( ---------------------------------- )
|
|
* dMajor
|
|
*
|
|
* where y(x) is the y coordinate of the pixel to be lit as a function of
|
|
* the x-coordinate.
|
|
*
|
|
* Every time the line advances one in the major direction 'x', dMinor
|
|
* gets added to the current error term. If the resulting value is >= 0,
|
|
* we know we have to move one pixel in the minor direction 'y', and
|
|
* dMajor must be subtracted from the current error term.
|
|
*
|
|
* If you're trying to figure out what this means for your hardware, you can
|
|
* think of the DDALINE terms as having been computed equivalently as
|
|
* follows:
|
|
*
|
|
* dMinor = 2 * (minor axis delta)
|
|
* dMajor = 2 * (major axis delta)
|
|
* lErrorTerm = - (major axis delta) - fixup
|
|
*
|
|
* That is, if your documentation tells you that for integer lines, a
|
|
* register is supposed to be initialized with the value
|
|
* '2 * (minor axis delta)', you'll actually use dMinor.
|
|
*
|
|
* Example: Setting up the 8514
|
|
*
|
|
* AXSTPSIGN is supposed to be the axial step constant register, defined
|
|
* as 2 * (minor axis delta). You set:
|
|
*
|
|
* AXSTPSIGN = dMinor
|
|
*
|
|
* DGSTPSIGN is supposed to be the diagonal step constant register,
|
|
* defined as 2 * (minor axis delta) - 2 * (major axis delta). You set:
|
|
*
|
|
* DGSTPSIGN = dMinor - dMajor
|
|
*
|
|
* ERR_TERM is supposed to be the adjusted error term, defined as
|
|
* 2 * (minor axis delta) - (major axis delta) - fixup. You set:
|
|
*
|
|
* ERR_TERM = lErrorTerm + dMinor
|
|
*
|
|
* Implementation:
|
|
*
|
|
* You'll want to special case integer lines before calling this routine
|
|
* (since they're very common, take less time to the computation of line
|
|
* terms, and can handle longer lines than this routine because 4 bits
|
|
* aren't being given to the fraction).
|
|
*
|
|
* If a GIQ line is too long to be handled by this routine, you can just
|
|
* use the slower strip routines for that line. Note that you cannot
|
|
* just fail the call -- you must be able to accurately draw any line
|
|
* in the 28.4 device space when it intersects the viewport.
|
|
*
|
|
* Testing:
|
|
*
|
|
* Use Guiman, or some other test that draws random fractional coordinate
|
|
* lines and compares them to what GDI itself draws to a bitmap.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
BOOL bHardwareLine(
|
|
PDEV* ppdev,
|
|
POINTFIX* pptfxStart, // Start of line
|
|
POINTFIX* pptfxEnd) // End of line
|
|
{
|
|
FLONG fl; // Various flags
|
|
ULONG M0; // Normalized fractional unit x start coordinate (0 <= M0 < F)
|
|
ULONG N0; // Normalized fractional unit y start coordinate (0 <= N0 < F)
|
|
ULONG M1; // Normalized fractional unit x end coordinate (0 <= M1 < F)
|
|
ULONG N1; // Normalized fractional unit x end coordinate (0 <= N1 < F)
|
|
ULONG dM; // Normalized fractional unit x-delta (0 <= dM)
|
|
ULONG dN; // Normalized fractional unit y-delta (0 <= dN <= dM)
|
|
LONG x; // Normalized x coordinate of origin
|
|
LONG y; // Normalized y coordinate of origin
|
|
LONG x0; // Normalized x offset from origin to start pixel (inclusive)
|
|
LONG y0; // Normalized y offset from origin to start pixel (inclusive)
|
|
LONG x1; // Normalized x offset from origin to end pixel (inclusive)
|
|
LONG lGamma;// Bresenham error term at origin
|
|
LONG cPels; // Number of pixels in line
|
|
BYTE* pjBase;
|
|
|
|
/***********************************************************************\
|
|
* Normalize line to the first octant.
|
|
\***********************************************************************/
|
|
|
|
fl = 0;
|
|
|
|
M0 = pptfxStart->x;
|
|
dM = pptfxEnd->x;
|
|
|
|
if ((LONG) dM < (LONG) M0)
|
|
{
|
|
// Line runs from right to left, so flip across x = 0:
|
|
|
|
M0 = -(LONG) M0;
|
|
dM = -(LONG) dM;
|
|
fl |= HW_FLIP_H;
|
|
}
|
|
|
|
// Compute the delta. The DDI says we can never have a valid delta
|
|
// with a magnitude more than 2^31 - 1, but the engine never actually
|
|
// checks its transforms. To ensure that we'll never puke on our shoes,
|
|
// we check for that case and simply refuse to draw the line:
|
|
|
|
dM -= M0;
|
|
if ((LONG) dM < 0)
|
|
return(FALSE);
|
|
|
|
N0 = pptfxStart->y;
|
|
dN = pptfxEnd->y;
|
|
|
|
if ((LONG) dN < (LONG) N0)
|
|
{
|
|
// Line runs from bottom to top, so flip across y = 0:
|
|
|
|
N0 = -(LONG) N0;
|
|
dN = -(LONG) dN;
|
|
fl |= HW_FLIP_V;
|
|
}
|
|
|
|
// Compute another delta:
|
|
|
|
dN -= N0;
|
|
if ((LONG) dN < 0)
|
|
return(FALSE);
|
|
|
|
if (dN >= dM)
|
|
{
|
|
if (dN == dM)
|
|
{
|
|
// Have to special case slopes of one:
|
|
|
|
fl |= HW_FLIP_SLOPE_ONE;
|
|
}
|
|
else
|
|
{
|
|
// Since line has slope greater than 1, flip across x = y:
|
|
|
|
register ULONG ulTmp;
|
|
ulTmp = dM; dM = dN; dN = ulTmp;
|
|
ulTmp = M0; M0 = N0; N0 = ulTmp;
|
|
fl |= HW_FLIP_D;
|
|
}
|
|
}
|
|
|
|
// Figure out if we can do the line in hardware, given that we have a
|
|
// limited number of bits of precision for the Bresenham terms.
|
|
//
|
|
// Remember that one bit has to be kept as a sign bit:
|
|
|
|
if ((LONG) dM >= (1L << (NUM_DDA_BITS - 1)))
|
|
return(FALSE);
|
|
|
|
fl |= gaflHardwareRound[fl];
|
|
|
|
/***********************************************************************\
|
|
* Calculate the error term at pixel 0.
|
|
\***********************************************************************/
|
|
|
|
x = LFLOOR((LONG) M0);
|
|
y = LFLOOR((LONG) N0);
|
|
|
|
M0 = FXFRAC(M0);
|
|
N0 = FXFRAC(N0);
|
|
|
|
// NOTE NOTE NOTE: If this routine were to handle any line in the 28.4
|
|
// space, it will overflow its math (the following part requires 36 bits
|
|
// of precision)! But we get here for lines that the hardware can handle
|
|
// (see the expression (dM >= (1L << (NUM_DDA_BITS - 1))) above?), so if
|
|
// cBits is less than 28, we're safe.
|
|
//
|
|
// If you're going to use this routine to handle all lines in the 28.4
|
|
// device space, you will HAVE to make sure the math doesn't overflow,
|
|
// otherwise you won't be NT compliant! (See 'bHardwareLine' for an example
|
|
// how to do that. You don't have to worry about this if you simply
|
|
// default to the strips code for long lines, because those routines
|
|
// already do the math correctly.)
|
|
|
|
// Calculate the remainder term [ dM * (N0 + F/2) - M0 * dN ]. Note
|
|
// that M0 and N0 have at most 4 bits of significance (and if the
|
|
// arguments are properly ordered, on a 486 each multiply would be no
|
|
// more than 13 cycles):
|
|
|
|
lGamma = (N0 + F/2) * dM - M0 * dN;
|
|
|
|
if (fl & HW_Y_ROUND_DOWN)
|
|
lGamma--;
|
|
|
|
lGamma >>= FLOG2;
|
|
|
|
/***********************************************************************\
|
|
* Figure out which pixels are at the ends of the line.
|
|
\***********************************************************************/
|
|
|
|
// The toughest part of GIQ is determining the start and end pels.
|
|
//
|
|
// Our approach here is to calculate x0 and x1 (the inclusive start
|
|
// and end columns of the line respectively, relative to our normalized
|
|
// origin). Then x1 - x0 + 1 is the number of pels in the line. The
|
|
// start point is easily calculated by plugging x0 into our line equation
|
|
// (which takes care of whether y = 1/2 rounds up or down in value)
|
|
// getting y0, and then undoing the normalizing flips to get back
|
|
// into device space.
|
|
//
|
|
// We look at the fractional parts of the coordinates of the start and
|
|
// end points, and call them (M0, N0) and (M1, N1) respectively, where
|
|
// 0 <= M0, N0, M1, N1 < 16. We plot (M0, N0) on the following grid
|
|
// to determine x0:
|
|
//
|
|
// +-----------------------> +x
|
|
// |
|
|
// | 0 1
|
|
// | 0123456789abcdef
|
|
// |
|
|
// | 0 ........?xxxxxxx
|
|
// | 1 ..........xxxxxx
|
|
// | 2 ...........xxxxx
|
|
// | 3 ............xxxx
|
|
// | 4 .............xxx
|
|
// | 5 ..............xx
|
|
// | 6 ...............x
|
|
// | 7 ................
|
|
// | 8 ................
|
|
// | 9 ......**........
|
|
// | a ........****...x
|
|
// | b ............****
|
|
// | c .............xxx****
|
|
// | d ............xxxx ****
|
|
// | e ...........xxxxx ****
|
|
// | f ..........xxxxxx
|
|
// |
|
|
// | 2 3
|
|
// v
|
|
//
|
|
// +y
|
|
//
|
|
// This grid accounts for the appropriate rounding of GIQ and last-pel
|
|
// exclusion. If (M0, N0) lands on an 'x', x0 = 2. If (M0, N0) lands
|
|
// on a '.', x0 = 1. If (M0, N0) lands on a '?', x0 rounds up or down,
|
|
// depending on what flips have been done to normalize the line.
|
|
//
|
|
// For the end point, if (M1, N1) lands on an 'x', x1 =
|
|
// floor((M0 + dM) / 16) + 1. If (M1, N1) lands on a '.', x1 =
|
|
// floor((M0 + dM)). If (M1, N1) lands on a '?', x1 rounds up or down,
|
|
// depending on what flips have been done to normalize the line.
|
|
//
|
|
// Lines of exactly slope one require a special case for both the start
|
|
// and end. For example, if the line ends such that (M1, N1) is (9, 1),
|
|
// the line has gone exactly through (8, 0) -- which may be considered
|
|
// to be part of 'x' because of rounding! So slopes of exactly slope
|
|
// one going through (8, 0) must also be considered as belonging in 'x'
|
|
// when an x value of 1/2 is supposed to round up in value.
|
|
|
|
// Calculate x0, x1:
|
|
|
|
N1 = FXFRAC(N0 + dN);
|
|
M1 = FXFRAC(M0 + dM);
|
|
|
|
x1 = LFLOOR(M0 + dM);
|
|
|
|
// Line runs left-to-right:
|
|
|
|
// Compute x1:
|
|
|
|
x1--;
|
|
if (M1 > 0)
|
|
{
|
|
if (N1 == 0)
|
|
{
|
|
if (LROUND(M1, fl & HW_X_ROUND_DOWN))
|
|
x1++;
|
|
}
|
|
else if (abs((LONG) (N1 - F/2)) <= (LONG) M1)
|
|
{
|
|
x1++;
|
|
}
|
|
}
|
|
|
|
if ((fl & (HW_FLIP_SLOPE_ONE | HW_X_ROUND_DOWN))
|
|
== (HW_FLIP_SLOPE_ONE | HW_X_ROUND_DOWN))
|
|
{
|
|
// Have to special-case diagonal lines going through our
|
|
// the point exactly equidistant between two horizontal
|
|
// pixels, if we're supposed to round x=1/2 down:
|
|
|
|
if ((M1 > 0) && (N1 == M1 + 8))
|
|
x1--;
|
|
|
|
if ((M0 > 0) && (N0 == M0 + 8))
|
|
{
|
|
x0 = 0;
|
|
goto left_to_right_compute_y0;
|
|
}
|
|
}
|
|
|
|
// Compute x0:
|
|
|
|
x0 = 0;
|
|
if (M0 > 0)
|
|
{
|
|
if (N0 == 0)
|
|
{
|
|
if (LROUND(M0, fl & HW_X_ROUND_DOWN))
|
|
x0 = 1;
|
|
}
|
|
else if (abs((LONG) (N0 - F/2)) <= (LONG) M0)
|
|
{
|
|
x0 = 1;
|
|
}
|
|
}
|
|
|
|
left_to_right_compute_y0:
|
|
|
|
/***********************************************************************\
|
|
* Calculate the start pixel.
|
|
\***********************************************************************/
|
|
|
|
// We now compute y0 and adjust the error term. We know x0, and we know
|
|
// the current formula for the pixels to be lit on the line:
|
|
//
|
|
// dN * x + lGamma
|
|
// y(x) = floor( --------------- )
|
|
// dM
|
|
//
|
|
// The remainder of this expression is the new error term at (x0, y0).
|
|
// Since x0 is going to be either 0 or 1, we don't actually have to do a
|
|
// multiply or divide to compute y0. Finally, we subtract dM from the
|
|
// new error term so that it is in the range [-dM, 0).
|
|
|
|
y0 = 0;
|
|
lGamma += (dN & (-x0));
|
|
lGamma -= dM;
|
|
if (lGamma >= 0)
|
|
{
|
|
y0 = 1;
|
|
lGamma -= dM;
|
|
}
|
|
|
|
// Undo our flips to get the start coordinate:
|
|
|
|
x += x0;
|
|
y += y0;
|
|
|
|
if (fl & HW_FLIP_D)
|
|
{
|
|
register LONG lTmp;
|
|
lTmp = x; x = y; y = lTmp;
|
|
}
|
|
|
|
if (fl & HW_FLIP_V)
|
|
{
|
|
y = -y;
|
|
}
|
|
|
|
if (fl & HW_FLIP_H)
|
|
{
|
|
x = -x;
|
|
}
|
|
|
|
/***********************************************************************\
|
|
* Return the Bresenham terms:
|
|
\***********************************************************************/
|
|
|
|
// iDir = gaiDir[fl & HW_FLIP_MASK];
|
|
// ptlStart.x = x;
|
|
// ptlStart.y = y;
|
|
// cPels = x1 - x0 + 1; // NOTE: You'll have to check if cPels <= 0!
|
|
// dMajor = dM;
|
|
// dMinor = dN;
|
|
// lErrorTerm = lGamma;
|
|
|
|
/***********************************************************************\
|
|
* Draw the line. MGA specific code follows:
|
|
\***********************************************************************/
|
|
|
|
cPels = x1 - x0 + 1;
|
|
if (cPels > 0)
|
|
{
|
|
pjBase = ppdev->pjBase;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, 9);
|
|
|
|
// Turn off MGA's autolines:
|
|
|
|
CP_WRITE(pjBase, DWG_DWGCTL, ppdev->ulLineControl & ~opcode_AUTO);
|
|
CP_WRITE(pjBase, DWG_LEN, cPels);
|
|
CP_WRITE(pjBase, DWG_SGN, gaiSign[fl & HW_FLIP_MASK]);
|
|
CP_WRITE(pjBase, DWG_AR0, dN);
|
|
CP_WRITE(pjBase, DWG_AR1, dN + lGamma);
|
|
CP_WRITE(pjBase, DWG_AR2, dN - dM);
|
|
CP_WRITE(pjBase, DWG_XDST, x + ppdev->xOffset);
|
|
CP_START(pjBase, DWG_YDST, y + ppdev->yOffset);
|
|
|
|
// Turn MGA's autolines back on, because strip code and horizontal
|
|
// and vertical line special cases expect it to be on:
|
|
|
|
CP_WRITE(pjBase, DWG_DWGCTL, ppdev->ulLineControl);
|
|
}
|
|
|
|
return(TRUE);
|
|
}
|
|
|
|
/*******************************Public*Table*******************************\
|
|
* gapfnStrip
|
|
*
|
|
* Look-up table for DrvStrokePath to find which strip routines to call.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
VOID (*gapfnStrip[])(PDEV*, STRIP*, LINESTATE*) = {
|
|
vStripSolidHorizontal,
|
|
vStripSolidVertical,
|
|
vStripSolidDiagonalHorizontal,
|
|
vStripSolidDiagonalVertical,
|
|
|
|
vStripStyledHorizontal,
|
|
vStripStyledVertical,
|
|
vStripStyledVertical, // Diagonal goes here
|
|
vStripStyledVertical, // Diagonal goes here
|
|
};
|
|
|
|
// Style array for alternate style (alternates one pixel on, one pixel off):
|
|
|
|
STYLEPOS gaspAlternateStyle[] = { 1 };
|
|
|
|
/******************************Public*Routine******************************\
|
|
* BOOL DrvStrokePath(pso, ppo, pco, pxo, pbo, pptlBrush, pla, mix)
|
|
*
|
|
* Strokes the path.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
BOOL DrvStrokePath(
|
|
SURFOBJ* pso,
|
|
PATHOBJ* ppo,
|
|
CLIPOBJ* pco,
|
|
XFORMOBJ* pxo,
|
|
BRUSHOBJ* pbo,
|
|
POINTL* pptlBrush,
|
|
LINEATTRS* pla,
|
|
MIX mix)
|
|
{
|
|
STYLEPOS aspLtoR[STYLE_MAX_COUNT];
|
|
STYLEPOS aspRtoL[STYLE_MAX_COUNT];
|
|
LINESTATE ls;
|
|
PFNSTRIP* apfn;
|
|
FLONG fl;
|
|
PDEV* ppdev;
|
|
DSURF* pdsurf;
|
|
OH* poh;
|
|
RECTL arclClip[4]; // For rectangular clipping
|
|
BYTE* pjBase;
|
|
RECTL* prclClip;
|
|
ULONG ulLinePattern;
|
|
ULONG ulHwMix;
|
|
PATHDATA pd;
|
|
BOOL bMore;
|
|
LONG cptfx;
|
|
POINTFIX ptfxStartFigure;
|
|
POINTFIX ptfxLast;
|
|
POINTFIX* pptfxFirst;
|
|
POINTFIX* pptfxBuf;
|
|
RECTFX rcfxBounds;
|
|
CLIPENUM ce;
|
|
LONG i;
|
|
|
|
ASSERTDD(((mix >> 8) & 0xff) == (mix & 0xff),
|
|
"GDI gave us an improper mix");
|
|
|
|
// Pass the surface off to GDI if it's a device bitmap that we've
|
|
// converted to a DIB:
|
|
|
|
pdsurf = (DSURF*) pso->dhsurf;
|
|
if (pdsurf->dt == DT_DIB)
|
|
{
|
|
return(EngStrokePath(pdsurf->pso, ppo, pco, pxo, pbo, pptlBrush,
|
|
pla, mix));
|
|
}
|
|
|
|
// We'll be drawing to the screen or an off-screen DFB; copy the surface's
|
|
// offset now so that we won't need to refer to the DSURF again:
|
|
|
|
poh = pdsurf->poh;
|
|
ppdev = (PDEV*) pso->dhpdev;
|
|
ppdev->xOffset = poh->x;
|
|
ppdev->yOffset = poh->y;
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
// MGA specific initialization:
|
|
|
|
pjBase = ppdev->pjBase;
|
|
|
|
CHECK_FIFO_SPACE(pjBase, 6);
|
|
|
|
if (mix == 0x0d0d) // R2_COPYPEN
|
|
{
|
|
ppdev->ulLineControl = (blockm_OFF + pattern_OFF + bltmod_BFCOL +
|
|
transc_BG_TRANSP + atype_RPL +
|
|
opcode_AUTOLINE_OPEN + bop_SRCCOPY +
|
|
solid_SOLID);
|
|
}
|
|
else
|
|
{
|
|
ulHwMix = (mix & 0xff) - 1;
|
|
|
|
ppdev->ulLineControl = (blockm_OFF + pattern_OFF + bltmod_BFCOL +
|
|
transc_BG_TRANSP + atype_RSTR +
|
|
opcode_AUTOLINE_OPEN + solid_SOLID +
|
|
(ulHwMix << 16));
|
|
}
|
|
|
|
CP_WRITE(pjBase, DWG_DWGCTL, ppdev->ulLineControl);
|
|
CP_WRITE(pjBase, DWG_FCOL, COLOR_REPLICATE(ppdev, pbo->iSolidColor));
|
|
|
|
if ((ppdev->ulBoardId != MGA_STORM) &&
|
|
!(GET_CACHE_FLAGS(ppdev, PATTERN_CACHE)))
|
|
{
|
|
CP_WRITE(pjBase, DWG_SRC0, 0xFFFFFFFF);
|
|
CP_WRITE(pjBase, DWG_SRC1, 0xFFFFFFFF);
|
|
CP_WRITE(pjBase, DWG_SRC2, 0xFFFFFFFF);
|
|
CP_WRITE(pjBase, DWG_SRC3, 0xFFFFFFFF);
|
|
}
|
|
|
|
ppdev->HopeFlags = PATTERN_CACHE;
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
// Special case solid integer lines:
|
|
|
|
if ((ppo->fl & PO_ALL_INTEGERS) &&
|
|
!(pla->fl & LA_STYLED))
|
|
{
|
|
// As of NT 4.0 SP2, the rasterization convention has been loosened
|
|
// for paths that have the PO_ALL_INTEGERS flag set. For those paths,
|
|
// you may do the 'tie-breaker' pixels anyway you like, which usually
|
|
// means that you can use the point-to-point line drawing capabilities
|
|
// of the hardware.
|
|
//
|
|
// HOWEVER: Your implementation must be invariant, regardless of clipping!
|
|
// This means that if you choose to deviate from the standard NT
|
|
// line convention, you MUST draw the same thing for DC_TRIVIAL,
|
|
// DC_RECT, *and* DC_COMPLEX clipping.
|
|
|
|
if (pco->iDComplexity == DC_TRIVIAL)
|
|
{
|
|
vLinesSimple(ppdev, ppo);
|
|
return(TRUE);
|
|
}
|
|
else
|
|
{
|
|
// We have to make sure that the path coordinates would not
|
|
// overflow our hardware precision! Note that the path's
|
|
// bounds are still expressed as 28.4 coordinates even if
|
|
// PO_ALL_INTEGERS or PO_ENUM_AS_INTEGERS is set:
|
|
|
|
PATHOBJ_vGetBounds(ppo, &rcfxBounds);
|
|
if ((rcfxBounds.xLeft >= 16 * MIN_INTEGER_BOUND) &&
|
|
(rcfxBounds.yTop >= 16 * MIN_INTEGER_BOUND) &&
|
|
(rcfxBounds.xRight <= 16 * MAX_INTEGER_BOUND) &&
|
|
(rcfxBounds.yBottom <= 16 * MAX_INTEGER_BOUND))
|
|
{
|
|
// NOTE that if you deviate from the standard NT line
|
|
// convention for PO_ALL_INTEGERS flags, you must support
|
|
// all clipping types!
|
|
|
|
if (pco->iDComplexity == DC_RECT)
|
|
{
|
|
vSetClipping(ppdev, &pco->rclBounds);
|
|
vLinesSimple(ppdev, ppo);
|
|
}
|
|
else
|
|
{
|
|
CLIPOBJ_cEnumStart(pco, FALSE, CT_RECTANGLES, CD_RIGHTDOWN,
|
|
0);
|
|
|
|
do {
|
|
// Get a batch of region rectangles:
|
|
|
|
bMore = CLIPOBJ_bEnum(pco, sizeof(ce), (VOID*) &ce);
|
|
for (i = 0; i < ce.c; i++)
|
|
{
|
|
vSetClipping(ppdev, &ce.arcl[i]);
|
|
vLinesSimple(ppdev, ppo);
|
|
}
|
|
} while (bMore);
|
|
}
|
|
|
|
vResetClipping(ppdev);
|
|
return(TRUE);
|
|
}
|
|
}
|
|
}
|
|
|
|
prclClip = NULL;
|
|
fl = 0;
|
|
ulLinePattern = (ULONG) -1;
|
|
|
|
// Look after styling initialization:
|
|
|
|
if (pla->fl & LA_ALTERNATE)
|
|
{
|
|
ls.cStyle = 1;
|
|
ls.spTotal = 1;
|
|
ls.spTotal2 = 2;
|
|
ls.spRemaining = 1;
|
|
ls.aspRtoL = &gaspAlternateStyle[0];
|
|
ls.aspLtoR = &gaspAlternateStyle[0];
|
|
ls.spNext = HIWORD(pla->elStyleState.l);
|
|
ls.xyDensity = 1;
|
|
fl |= FL_STYLED;
|
|
ls.ulStartMask = 0L;
|
|
}
|
|
else if (pla->pstyle != (FLOAT_LONG*) NULL)
|
|
{
|
|
PFLOAT_LONG pstyle;
|
|
STYLEPOS* pspDown;
|
|
STYLEPOS* pspUp;
|
|
|
|
pstyle = &pla->pstyle[pla->cstyle];
|
|
|
|
ls.xyDensity = STYLE_DENSITY;
|
|
ls.spTotal = 0;
|
|
while (pstyle-- > pla->pstyle)
|
|
{
|
|
ls.spTotal += pstyle->l;
|
|
}
|
|
ls.spTotal *= STYLE_DENSITY;
|
|
ls.spTotal2 = 2 * ls.spTotal;
|
|
|
|
// Compute starting style position (this is guaranteed not to overflow):
|
|
|
|
ls.spNext = HIWORD(pla->elStyleState.l) * STYLE_DENSITY +
|
|
LOWORD(pla->elStyleState.l);
|
|
|
|
fl |= FL_STYLED;
|
|
ls.cStyle = pla->cstyle;
|
|
ls.aspRtoL = aspRtoL;
|
|
ls.aspLtoR = aspLtoR;
|
|
|
|
if (pla->fl & LA_STARTGAP)
|
|
ls.ulStartMask = 0xffffffffL;
|
|
else
|
|
ls.ulStartMask = 0L;
|
|
|
|
pstyle = pla->pstyle;
|
|
pspDown = &ls.aspRtoL[ls.cStyle - 1];
|
|
pspUp = &ls.aspLtoR[0];
|
|
|
|
while (pspDown >= &ls.aspRtoL[0])
|
|
{
|
|
*pspDown = pstyle->l * STYLE_DENSITY;
|
|
*pspUp = *pspDown;
|
|
|
|
pspUp++;
|
|
pspDown--;
|
|
pstyle++;
|
|
}
|
|
}
|
|
|
|
if (pco->iDComplexity == DC_RECT)
|
|
{
|
|
fl |= FL_SIMPLE_CLIP;
|
|
|
|
arclClip[0] = pco->rclBounds;
|
|
|
|
// FL_FLIP_D:
|
|
|
|
arclClip[1].top = pco->rclBounds.left;
|
|
arclClip[1].left = pco->rclBounds.top;
|
|
arclClip[1].bottom = pco->rclBounds.right;
|
|
arclClip[1].right = pco->rclBounds.bottom;
|
|
|
|
// FL_FLIP_V:
|
|
|
|
arclClip[2].top = -pco->rclBounds.bottom + 1;
|
|
arclClip[2].left = pco->rclBounds.left;
|
|
arclClip[2].bottom = -pco->rclBounds.top + 1;
|
|
arclClip[2].right = pco->rclBounds.right;
|
|
|
|
// FL_FLIP_V | FL_FLIP_D:
|
|
|
|
arclClip[3].top = pco->rclBounds.left;
|
|
arclClip[3].left = -pco->rclBounds.bottom + 1;
|
|
arclClip[3].bottom = pco->rclBounds.right;
|
|
arclClip[3].right = -pco->rclBounds.top + 1;
|
|
|
|
prclClip = arclClip;
|
|
}
|
|
|
|
apfn = &gapfnStrip[4 * ((fl & FL_STYLE_MASK) >> FL_STYLE_SHIFT)];
|
|
|
|
|
|
//////////////////////////////////////////////////////////////////////
|
|
// Set up to enumerate the path:
|
|
|
|
if (pco->iDComplexity != DC_COMPLEX)
|
|
{
|
|
pd.flags = 0;
|
|
|
|
do {
|
|
bMore = PATHOBJ_bEnum(ppo, &pd);
|
|
|
|
cptfx = pd.count;
|
|
if (cptfx == 0)
|
|
break;
|
|
|
|
if (pd.flags & PD_BEGINSUBPATH)
|
|
{
|
|
ptfxStartFigure = *pd.pptfx;
|
|
pptfxFirst = pd.pptfx;
|
|
pptfxBuf = pd.pptfx + 1;
|
|
cptfx--;
|
|
}
|
|
else
|
|
{
|
|
pptfxFirst = &ptfxLast;
|
|
pptfxBuf = pd.pptfx;
|
|
}
|
|
|
|
if (pd.flags & PD_RESETSTYLE)
|
|
ls.spNext = 0;
|
|
|
|
if (cptfx > 0)
|
|
{
|
|
if (!bLinesComplex(ppdev,
|
|
pptfxFirst,
|
|
pptfxBuf,
|
|
(RUN*) NULL,
|
|
cptfx,
|
|
&ls,
|
|
prclClip,
|
|
apfn,
|
|
fl))
|
|
return(FALSE);
|
|
}
|
|
|
|
ptfxLast = pd.pptfx[pd.count - 1];
|
|
|
|
if (pd.flags & PD_CLOSEFIGURE)
|
|
{
|
|
if (!bLinesComplex(ppdev,
|
|
&ptfxLast,
|
|
&ptfxStartFigure,
|
|
(RUN*) NULL,
|
|
1,
|
|
&ls,
|
|
prclClip,
|
|
apfn,
|
|
fl))
|
|
return(FALSE);
|
|
}
|
|
} while (bMore);
|
|
|
|
if (fl & FL_STYLED)
|
|
{
|
|
// Save the style state:
|
|
|
|
ULONG ulHigh;
|
|
ULONG ulLow;
|
|
|
|
// Masked styles don't normalize the style state. It's a good
|
|
// thing to do, so let's do it now:
|
|
|
|
if ((ULONG) ls.spNext >= (ULONG) ls.spTotal2)
|
|
ls.spNext = (ULONG) ls.spNext % (ULONG) ls.spTotal2;
|
|
|
|
ulHigh = ls.spNext / ls.xyDensity;
|
|
ulLow = ls.spNext % ls.xyDensity;
|
|
|
|
pla->elStyleState.l = MAKELONG(ulLow, ulHigh);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
// Local state for path enumeration:
|
|
|
|
BOOL bMore;
|
|
union {
|
|
BYTE aj[offsetof(CLIPLINE, arun) + RUN_MAX * sizeof(RUN)];
|
|
CLIPLINE cl;
|
|
} cl;
|
|
|
|
fl |= FL_COMPLEX_CLIP;
|
|
|
|
// We use the clip object when non-simple clipping is involved:
|
|
|
|
PATHOBJ_vEnumStartClipLines(ppo, pco, pso, pla);
|
|
|
|
do {
|
|
bMore = PATHOBJ_bEnumClipLines(ppo, sizeof(cl), &cl.cl);
|
|
if (cl.cl.c != 0)
|
|
{
|
|
if (fl & FL_STYLED)
|
|
{
|
|
ls.spComplex = HIWORD(cl.cl.lStyleState) * ls.xyDensity
|
|
+ LOWORD(cl.cl.lStyleState);
|
|
}
|
|
if (!bLinesComplex(ppdev,
|
|
&cl.cl.ptfxA,
|
|
&cl.cl.ptfxB,
|
|
&cl.cl.arun[0],
|
|
cl.cl.c,
|
|
&ls,
|
|
(RECTL*) NULL,
|
|
apfn,
|
|
fl))
|
|
return(FALSE);
|
|
}
|
|
} while (bMore);
|
|
}
|
|
|
|
return(TRUE);
|
|
}
|
|
|