windows-nt/Source/XPSP1/NT/multimedia/opengl/scrsave/common/clear.cxx
2020-09-26 16:20:57 +08:00

411 lines
10 KiB
C++

/******************************Module*Header*******************************\
* Module Name: clear.cxx
*
* Window clearing functions
*
* Copyright (c) 1996 Microsoft Corporation
*
\**************************************************************************/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <windows.h>
#include <sys/timeb.h>
#include <GL/gl.h>
#include <sys/types.h>
#include <sys/timeb.h>
#include <time.h>
#include <math.h>
#include "ssintrnl.hxx"
#include "util.hxx"
#include "clear.hxx"
#define SS_CLEAR_BASE_DIV 32
#define SS_CLEAR_BASE_SIZE 16
/******************************Public*Routine******************************\
* ss_RectWipeClear
*
* Clears by drawing top, bottom, left, right rectangles that shrink in size
* towards the center.
*
* Calibration is used to try to maintain an ideal clear time.
*
\**************************************************************************/
int
ss_RectWipeClear( int width, int height, int repCount )
{
int i, j, xinc, yinc, numDivs;
int xmin, xmax, ymin, ymax;
int w, h;
BOOL bCalibrate = FALSE;
double elapsed;
static double idealTime = 0.7;
SS_TIMER timer;
xinc = 1;
yinc = 1;
numDivs = height; // assumes height <= width
xmin = ymin = 0;
xmax = width-1;
ymax = height-1;
glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
glEnable( GL_SCISSOR_TEST );
if( repCount == 0 ) {
bCalibrate = TRUE;
repCount = 1;
timer.Start();
}
for( i = 0; i < (numDivs/2); i ++ ) {
w = xmax - xmin + 1;
h = ymax - ymin + 1;
for( j = 0; j < repCount; j ++ ) {
// bottom
glScissor( xmin, ymin, w, 1 );
glClear( GL_COLOR_BUFFER_BIT );
// left
glScissor( xmin, ymin, 1, h );
glClear( GL_COLOR_BUFFER_BIT );
// right
glScissor( xmax, ymin, 1, h );
glClear( GL_COLOR_BUFFER_BIT );
// top
glScissor( xmin, ymax, w, 1 );
glClear( GL_COLOR_BUFFER_BIT );
glFlush(); // to eliminate 'bursts'
}
xmin += xinc;
xmax -= xinc;
ymin += yinc;
ymax -= yinc;
}
if( bCalibrate ) {
elapsed = timer.Stop();
// try to maintain ideal clear time
if( elapsed < idealTime ) {
// increase repCount to slow down the clear
if( elapsed == 0.0 )
repCount = 10; // just in case
else
repCount = (int) ((idealTime / elapsed) + 0.5);
}
}
glDisable( GL_SCISSOR_TEST );
return repCount;
}
#define SS_CLEAR_BASE_DIV 32
/******************************Public*Routine******************************\
*
* SS_DIGITAL_DISSOLVE_CLEAR constructor
*
\**************************************************************************/
SS_DIGITAL_DISSOLVE_CLEAR::
SS_DIGITAL_DISSOLVE_CLEAR()
{
rectBuf = NULL;
rectBufSize = 0;
rectSize = SS_CLEAR_BASE_SIZE;
}
/******************************Public*Routine******************************\
*
* SS_DIGITAL_DISSOLVE_CLEAR destructor
*
\**************************************************************************/
SS_DIGITAL_DISSOLVE_CLEAR::
~SS_DIGITAL_DISSOLVE_CLEAR()
{
if( rectBuf )
LocalFree( rectBuf );
}
/******************************Public*Routine******************************\
* CalibrateClear
*
* Try to calibrate the clear so it takes the specified time
\**************************************************************************/
//#define AUTO_CALIBRATE 1
int SS_DIGITAL_DISSOLVE_CLEAR::
CalibrateClear( int width, int height, float fClearTime )
{
float factor;
int idealNRects;
int nRects;
int baseSize;
SS_TIMER timer;
float elapsed;
baseSize = (width < height ? width : height) / SS_CLEAR_BASE_DIV;
if( baseSize == 0 )
baseSize = 1;
timer.Start();
#ifdef AUTO_CALIBRATE
// Clear a small region (quarter-screen) and extrapolate
Clear( width >> 1, height >> 1, baseSize );
#else
Clear( width, height, baseSize );
#endif
elapsed = timer.Stop();
#ifdef AUTO_CALIBRATE
// extrapolate to full screen time
// mf: this approximation resulted in clears being somewhat less than ideal
// I guess this means more time than I thought was spent in scanning up
// or down for uncleared rects
elapsed *= 4.0f;
#endif
// Adjust size of rects for ideal clear time
if( elapsed <= 0.0f ) {
rectSize = 1;
return rectSize;
}
nRects = RectangleCount( width, height, baseSize );
factor = fClearTime / elapsed;
idealNRects = (int) (factor * (float)nRects);
rectSize = (int) (sqrt( (double)(width*height) / (double)idealNRects ) + 0.5);
if( rectSize == 0 )
rectSize = 1;
return rectSize;
}
/******************************Public*Routine******************************\
*
* SS_DIGITAL_DISSOLVE_CLEAR::Clear
*
* Clears by drawing random rectangles
*
\**************************************************************************/
BOOL SS_DIGITAL_DISSOLVE_CLEAR::
Clear( int width, int height )
{
return Clear( width, height, rectSize );
}
BOOL SS_DIGITAL_DISSOLVE_CLEAR::
Clear( int width, int height, int size )
{
BOOL *pRect;
BOOL bCalibrate = FALSE;
int count, nRects;
int i, xdim, ydim;
static float idealTime = 2.0f;
if( (size <= 0) || !width || !height )
return FALSE;
// determine xdim, ydim from size
xdim = SS_ROUND_UP( (float)width / (float)size );
ydim = SS_ROUND_UP( (float)height / (float) size );
// figure out how many rects needed
count = nRects = xdim * ydim;
// make sure enough room
if( !ValidateBufSize( nRects ) )
return FALSE;
// reset the rect array to uncleared
pRect = rectBuf;
for( i = 0; i < count; i ++, pRect++ )
*pRect = FALSE;
// Clear random rectangles
glEnable( GL_SCISSOR_TEST );
while( count ) {
// pick a random rect
i = ss_iRand( nRects );
if( rectBuf[i] ) {
// This rect has already been cleared - find an empty one
// Scan up and down from x,y, looking at the array linearly
int up, down;
BOOL searchUp = FALSE;
up = down = i;
pRect = rectBuf;
while( *(pRect + i) ) {
if( searchUp ) {
// search up side
if( up < (nRects-1) ) {
up++;
}
i = up;
} else {
// search down side
if( down > 0 ) {
down--;
}
i = down;
}
searchUp = !searchUp;
}
}
// clear the x,y rect
glScissor( (i % xdim)*size, (i / xdim)*size, size, size );
glClear( GL_COLOR_BUFFER_BIT );
glFlush();
rectBuf[i] = TRUE; // mark as taken
count--;
}
glDisable( GL_SCISSOR_TEST );
return TRUE;
}
/******************************Public*Routine******************************\
* RectangleCount
*
\**************************************************************************/
int SS_DIGITAL_DISSOLVE_CLEAR::
RectangleCount( int width, int height, int size )
{
return SS_ROUND_UP( (float)width / (float)size ) *
SS_ROUND_UP( (float)height / (float) size );
}
/******************************Public*Routine******************************\
* ValidateBufSize
*
\**************************************************************************/
BOOL SS_DIGITAL_DISSOLVE_CLEAR::
ValidateBufSize( int nRects )
{
if( nRects > rectBufSize ) {
// need a bigger rect buf
BOOL *r = (BOOL *) LocalAlloc( LMEM_FIXED, sizeof(BOOL) * nRects );
if( !r )
return FALSE;
if( rectBuf )
LocalFree( rectBuf );
rectBuf = r;
rectBufSize = nRects;
}
return TRUE;
}
/******************************Public*Routine******************************\
* DrawGdiRect
*
* Clears the rect with the brush
\**************************************************************************/
void
DrawGdiRect( HDC hdc, HBRUSH hbr, RECT *pRect )
{
if( pRect == NULL )
return;
FillRect( hdc, pRect, hbr );
GdiFlush();
}
#ifdef SS_INITIAL_CLEAR
/*-----------------------------------------------------------------------
|
| RectWipeClear(width, height):
| - Does a rectangular wipe (or clear) by drawing in a sequence
| of rectangles using Gdi
| MOD: add calibrator capability to adjust speed for different
| architectures
| MOD: this can be further optimized by caching the brush
|
-----------------------------------------------------------------------*/
void
ss_GdiRectWipeClear( HWND hwnd, int width, int height )
{
HDC hdc;
HBRUSH hbr;
RECT rect;
int i, j, xinc, yinc, numDivs = 500;
int xmin, xmax, ymin, ymax;
int repCount = 10;
xinc = 1;
yinc = 1;
numDivs = height;
xmin = ymin = 0;
xmax = width;
ymax = height;
hdc = GetDC( hwnd );
hbr = CreateSolidBrush( RGB( 0, 0, 0 ) );
for( i = 0; i < (numDivs/2 - 1); i ++ ) {
for( j = 0; j < repCount; j ++ ) {
rect.left = xmin; rect.top = ymin;
rect.right = xmax; rect.bottom = ymin + yinc;
FillRect( hdc, &rect, hbr );
rect.top = ymax - yinc;
rect.bottom = ymax;
FillRect( hdc, &rect, hbr );
rect.top = ymin + yinc;
rect.right = xmin + xinc; rect.bottom = ymax - yinc;
FillRect( hdc, &rect, hbr );
rect.left = xmax - xinc; rect.top = ymin + yinc;
rect.right = xmax; rect.bottom = ymax - yinc;
FillRect( hdc, &rect, hbr );
}
xmin += xinc;
xmax -= xinc;
ymin += yinc;
ymax -= yinc;
}
// clear last square in middle
rect.left = xmin; rect.top = ymin;
rect.right = xmax; rect.bottom = ymax;
FillRect( hdc, &rect, hbr );
DeleteObject( hbr );
ReleaseDC( hwnd, hdc );
GdiFlush();
}
#endif // SS_INITIAL_CLEAR