RosettaCodeData/Task/Bitmap-Bresenhams-line-algo.../D/bitmap-bresenhams-line-algo...

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1.3 KiB
D

module bitmap_bresenhams_line_algorithm;
import std.algorithm, std.math, bitmap;
void drawLine(Color)(Image!Color img,
size_t x1, size_t y1,
in size_t x2, in size_t y2,
in Color color)
pure nothrow @nogc {
immutable int dx = x2 - x1;
immutable int ix = (dx > 0) - (dx < 0);
immutable size_t dx2 = abs(dx) * 2;
int dy = y2 - y1;
immutable int iy = (dy > 0) - (dy < 0);
immutable size_t dy2 = abs(dy) * 2;
img[x1, y1] = color;
if (dx2 >= dy2) {
int error = dy2 - (dx2 / 2);
while (x1 != x2) {
if (error >= 0 && (error || (ix > 0))) {
error -= dx2;
y1 += iy;
}
error += dy2;
x1 += ix;
img[x1, y1] = color;
}
} else {
int error = dx2 - (dy2 / 2);
while (y1 != y2) {
if (error >= 0 && (error || (iy > 0))) {
error -= dy2;
x1 += ix;
}
error += dx2;
y1 += iy;
img[x1, y1] = color;
}
}
}
version (bitmap_bresenhams_line_algorithm_main) {
void main() {
auto img = new Image!RGB(25, 22);
img.drawLine(5, 5, 15, 20, RGB.white);
img.drawLine(3, 20, 10, 12, RGB.white);
img.textualShow();
}
}