1
0
Fork 0
forked from AbleOS/ableos
ableos_time/sysdata/programs/fb_driver/src/draw.hb
2024-08-20 13:03:39 +01:00

113 lines
2.7 KiB
Plaintext

.{draw_pixel, screenidx, Transform, Point, Rect, Buffer, FB_WIDTH} := @use("rel:lib.hb")
ColorBGRA := @use("rel:color.hb").ColorBGRA
math := @use("../../../libraries/stn/src/lib.hb").math
/* draws a filled rectangle to the screen
will be optimised later */
rect_fill := fn(buffer: Buffer, pos: Point, tr: Transform, color: ColorBGRA): void {
n := 0
loop if n == tr.height * tr.width break else {
*(buffer.write + screenidx(.(n % tr.width + pos.x, n / tr.width + pos.y))) = color
n += 1
}
return
}
/* draws a wireframe rectangle to the screen
will also be optimised later */
rect_line := fn(buffer: Buffer, pos: Point, tr: Transform, color: ColorBGRA, thickness: int): void {
t := 0
y := 0
x := 0
loop if t == thickness break else {
y = pos.y
x = pos.x
loop if y == pos.y + tr.height break else {
*(buffer.write + pos.x + t + FB_WIDTH * y) = color;
*(buffer.write + pos.x + tr.width - t + FB_WIDTH * y) = color
y += 1
}
loop if x == pos.x + tr.width break else {
*(buffer.write + x + (pos.y + t) * FB_WIDTH) = color;
*(buffer.write + x + (pos.y + tr.height - t) * FB_WIDTH) = color
x += 1
}
t += 1
}
return
}
// do not use, use line() instead
line_low := fn(buffer: Buffer, p0: Point, p1: Point, color: ColorBGRA): void {
dx := p1.x - p0.x
dy := p1.y - p0.y
yi := 1
if dy < 0 {
yi = 0 - 1
dy = 0 - dy
}
D := 2 * dy - dx
y := p0.y
x := p0.x
loop if x == p1.x break else {
*(buffer.write + x + y * FB_WIDTH) = color
if D > 0 {
y += yi
D += 2 * (dy - dx)
} else {
D += 2 * dy
}
x += 1
}
return
}
// do not use, use line() instead
line_high := fn(buffer: Buffer, p0: Point, p1: Point, color: ColorBGRA): void {
dx := p1.x - p0.x
dy := p1.y - p0.y
xi := 1
if dy < 0 {
xi = 0 - 1
dx = 0 - dx
}
D := 2 * dx - dy
x := p0.x
y := p0.y
loop if y == p1.y break else {
*(buffer.write + x + y * FB_WIDTH) = color
if D > 0 {
x += xi
D += 2 * (dx - dy)
} else {
D += 2 * dx
}
y += 1
}
return
}
/* implementation of Bresenham's line algorithm
TODO: thickness, might need better math library */
line := fn(buffer: Buffer, p0: Point, p1: Point, color: ColorBGRA, thickness: int): void {
if math.abs(p1.y - p0.y) < math.abs(p1.x - p0.x) {
if p0.x > p1.x {
line_low(buffer, p1, p0, color)
} else {
line_low(buffer, p0, p1, color)
}
} else {
if p0.y > p1.y {
line_high(buffer, p1, p0, color)
} else {
line_high(buffer, p0, p1, color)
}
}
return
}
// theoretically draws a wireframe polygon to the screen. untested.
tri_line := fn(buffer: Buffer, p0: Point, p1: Point, p2: Point, color: ColorBGRA, thickness: int): void {
line(buffer, p0, p1, color, thickness)
line(buffer, p1, p2, color, thickness)
line(buffer, p2, p0, color, thickness)
return
}