Bresenham’s line drawing algorithm implemetations in Go and C.
Couple of Bresenham’s line drawing implementations in C and Go. They will need hacking to suit your application.
void display_draw_line(int start_x,int start_y,int end_x,int end_y,uint16_t color) {
// Bresenham's
int cx = start_x;
int cy = start_y;
int dx = end_x - cx;
int dy = end_y - cy;
if(dx<0) dx = 0-dx;
if(dy<0) dy = 0-dy;
int sx=0; int sy=0;
if(cx < end_x) sx = 1; else sx = -1;
if(cy < end_y) sy = 1; else sy = -1;
int err = dx-dy;
for(int n=0;n<1000;n++) {
display_draw_point(cx,cy,color);
if((cx==end_x) && (cy==end_y)) return;
int e2 = 2*err;
if(e2 > (0-dy)) { err = err - dy; cx = cx + sx; }
if(e2 < dx ) { err = err + dx; cy = cy + sy; }
}
}
And golang:
func draw_line(start_x int32,start_y int32,end_x int32,end_y int32,color uint32,screen* sdl.Surface) {
// Bresenham's
var cx int32 = start_x;
var cy int32 = start_y;
var dx int32 = end_x - cx;
var dy int32 = end_y - cy;
if dx<0 { dx = 0-dx; }
if dy<0 { dy = 0-dy; }
var sx int32;
var sy int32;
if cx < end_x { sx = 1; } else { sx = -1; }
if cy < end_y { sy = 1; } else { sy = -1; }
var err int32 = dx-dy;
var n int32;
for n=0;n<1000;n++ {
draw_point(cx,cy,color,screen);
if((cx==end_x) && (cy==end_y)) {return;}
var e2 int32 = 2*err;
if e2 > (0-dy) { err = err - dy; cx = cx + sx; }
if e2 < dx { err = err + dx; cy = cy + sy; }
}
}
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