diff options
Diffstat (limited to 'drawing.ha')
| -rw-r--r-- | drawing.ha | 41 |
1 files changed, 30 insertions, 11 deletions
@@ -1,14 +1,13 @@ use sdl2; - // 2d position, x and y -type pos = (int, int); +type pos = (i32, i32); type drawing_state = struct { // is the mouse button held down? drawing: bool, pos: pos, - picture: picture, + picture: *picture, }; type picture = struct { @@ -16,6 +15,7 @@ type picture = struct { w: size, h: size, }; + // Returns array index of the pixel at position pos. // Bounds check happens in here instead of using a slice type, so // that it's easier to remove later. @@ -29,22 +29,42 @@ fn pidx(pic: *picture, pos: pos) size = { return xs + pic.w*ys; }; -fn pic_set(pic: *picture, pos: pos, val: u32) void = pic.d[pidx(pic,pos)] = val; + +fn pic_set(pic: *picture, pos: pos, val: u32) void = + pic.d[pidx(pic,pos)] = val; + fn picture_from_surface(surf: *sdl2::SDL_Surface) picture = picture { w = surf.w: size, h = surf.h: size, d = (surf.pixels as *opaque: *[*]u32), }; -fn min(a: int, b: int) int = if (a<b) a else b; -fn max(a: int, b: int) int = if (a<b) b else a; +fn clear_picture(pic: *picture, color: u32) void = { + for (let i = 0z; i < pic.w*pic.h; i+=1) pic.d[i] = color; +}; -fn circle(dstate: *drawing_state, c: pos, r: int, color: u32) void = { +fn outline_picture(pic: *picture) void = { + for (let x = 0; x:size < pic.w; x+=1) { + pic_set(pic, (x, 0), 0); + pic_set(pic, (x, pic.h:int-1), 0); + }; + for (let y = 0; y:size < pic.h; y+=1) { + pic_set(pic, (0, y), 0); + pic_set(pic, (pic.w:int-1, y), 0); + }; +}; + +fn min(a: i32, b: i32) i32 = if (a<b) a else b; +fn max(a: i32, b: i32) i32 = if (a<b) b else a; + +// Draws a circle onto the dstate's picture, at given position radius color +// Clips at the boundaries of the picture to avoid overflow. +fn circle(dstate: *drawing_state, c: pos, r: i32, color: u32) void = { const (cx,cy) = c; const ymin = max(0, cy-r); - const ymax = min(dstate.picture.h:int-1, cy+r); + const ymax = min(dstate.picture.h:i32-1, cy+r); const xmin = max(0, cx-r); - const xmax = min(dstate.picture.w:int-1, cx+r); + const xmax = min(dstate.picture.w:i32-1, cx+r); const r2 = r*r + r; @@ -53,11 +73,10 @@ fn circle(dstate: *drawing_state, c: pos, r: int, color: u32) void = { for (let x = xmin; x<=xmax; x+=1) { const xd = x-cx; if (yd*yd + xd*xd <= r2) { - pic_set(&dstate.picture, (x,y), color); + pic_set(dstate.picture, (x,y), color); }; }; }; - }; fn do_drawing(dstate: *drawing_state) void = { |