diff options
| -rw-r--r-- | examples/triangle.c | 10 | ||||
| -rw-r--r-- | examples/triangles.c | 10 | ||||
| -rw-r--r-- | sponge.h | 165 |
3 files changed, 92 insertions, 93 deletions
diff --git a/examples/triangle.c b/examples/triangle.c index a39ee1b..a3559e9 100644 --- a/examples/triangle.c +++ b/examples/triangle.c @@ -6,7 +6,7 @@ static int32_t offset = 0; void init() {} void draw_frame(sponge_Texture c) { - sponge_clear(c, 0xFF000000); + sponge_clear(c, sponge_color32_make(0xFF000000)); offset += SPEED; if (offset > 100) @@ -14,8 +14,8 @@ void draw_frame(sponge_Texture c) { sponge_draw_triangle_col3( c, - 30, 30 + offset, - c.width - 30, 50 + offset, - 30, c.height - 30 + offset, - 0xFFFF0000, 0xFF00FF00, 0xFF0000FF); + sponge_vec2i_make(30, 30 + offset), + sponge_vec2i_make(c.width - 30, 50 + offset), + sponge_vec2i_make(30, c.height - 30 + offset), + sponge_colorf_make(0xFFFF0000), sponge_colorf_make(0xFF00FF00), sponge_colorf_make(0xFF0000FF)); } diff --git a/examples/triangles.c b/examples/triangles.c index 8515a28..271de5f 100644 --- a/examples/triangles.c +++ b/examples/triangles.c @@ -10,7 +10,7 @@ static int32_t speed = SPEED_ABS; void init() {} void draw_frame(sponge_Texture c) { - sponge_clear(c, 0xFF000000); + sponge_clear(c, sponge_color32_make(0xFF000000)); offset += speed; if (offset > 30) { @@ -29,10 +29,10 @@ void draw_frame(sponge_Texture c) { sponge_draw_triangle_col3( c, - x, y + offset_y, - x + offset_x, y, - x + (offset_x * 3 / 4), y + (offset_y * 3 / 4), - 0xFFFF0000, 0xFF00FF00, 0xFF0000FF); + sponge_vec2i_make(x, y + offset_y), + sponge_vec2i_make(x + offset_x, y), + sponge_vec2i_make(x + (offset_x * 3 / 4), y + (offset_y * 3 / 4)), + sponge_colorf_make(0xFFFF0000), sponge_colorf_make(0xFF00FF00), sponge_colorf_make(0xFF0000FF)); } } } @@ -50,6 +50,7 @@ sponge_Vec4 sponge_vec4_make(float x, float y, float z, float w); // in sponge apis components expected to be between 0.0 and 255.0 #define sponge_ColorF sponge_Vec4 +sponge_ColorF sponge_colorf_make(uint32_t value); typedef struct { int32_t x; @@ -69,7 +70,7 @@ sponge_Color32 sponge_colorf_to_color32(sponge_ColorF col); // checks if tex.width or tex.height is equal to 0 // calling sponge functions with invalid textures is not supported -int sponge_texture_valid(sponge_Texture tex); +int32_t sponge_texture_valid(sponge_Texture tex); // first argument is always rendering target (canvas) void sponge_clear (sponge_Texture c, sponge_Color32 col); @@ -78,18 +79,33 @@ void sponge_draw_rect (sponge_Texture c, sponge_Vec2I v0, sponge_Vec2I v1, spo void sponge_draw_line (sponge_Texture c, sponge_Vec2I v0, sponge_Vec2I v1, sponge_Color32 col); void sponge_draw_texture(sponge_Texture c, sponge_Vec2I offset, sponge_Texture tex); -//void sponge_draw_triangle_col (sponge_Texture c, sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2, sponge_Color32 col); -//void sponge_draw_triangle_col3(sponge_Texture c, -// sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2, -// sponge_ColorF col0, sponge_ColorF col1, sponge_ColorF col2); +// tests on which side of the line p is (negative on the left, positive on the right) +int32_t sponge_edge_function(sponge_Vec2I p, sponge_Vec2I v0, sponge_Vec2I v1); + +// out_area2 is optional +void sponge_draw_triangle_init( + sponge_Texture c, sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2, + sponge_Vec2I *out_min, sponge_Vec2I *out_max, float *out_area2); + +// non-zero if p inside triangle, outputs only valid if inside +int32_t sponge_draw_triangle_iter( + sponge_Vec2I p, sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2, float area2, + float *w0, float *w1, float *w2); + +void sponge_draw_triangle_col3( + sponge_Texture c, + sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2, + sponge_ColorF col0, sponge_ColorF col1, sponge_ColorF col2); #define SPONGE_CLAMP(val, min, max) ((val) < (min) ? (min) : ((val) > (max) ? (max) : (val))) #define SPONGE_MIN(x, y) ((x) < (y) ? (x) : (y)) #define SPONGE_MAX(x, y) ((x) > (y) ? (x) : (y)) #define SPONGE_ABS(x) ((x) >= 0 ? (x) : -(x)) + // TODO(kard): prefix stripping + #ifdef SPONGE_IMPLEMENTATION // can be defined as nop in release builds @@ -107,6 +123,15 @@ sponge_Color32 sponge_color32_make(uint32_t value) { result.b = (value & 0x000000FF); return result; } +sponge_ColorF sponge_colorf_make(uint32_t value) { + sponge_ColorF result; + sponge_Color32 c32 = sponge_color32_make(value); + result.a = (float)c32.a; + result.r = (float)c32.r; + result.g = (float)c32.g; + result.b = (float)c32.b; + return result; +} sponge_Vec2 sponge_vec2_make(float x, float y) { sponge_Vec2 result; result.x = x; @@ -167,37 +192,8 @@ sponge_Vec4 sponge_vec4_mul(sponge_Vec4 v0, float f) { return v0; } -// sponge__BarycentricContext sponge__barycentric_init(sponge_Vec2 t0, sponge_Vec2 t1, sponge_Vec2 t2) { - // sponge__BarycentricContext result; - // result.v0 = sponge_sub2(t1, t0); - // result.v1 = sponge_sub2(t2, t0); - // result.d00 = sponge_dot2(result.v0, result.v0); - // result.d01 = sponge_dot2(result.v0, result.v1); - // result.d11 = sponge_dot2(result.v1, result.v1); - // result.denom = (result.d00 * result.d11) - (result.d01 * result.d01); - // return result; -// } -// -// void sponge__barycentric( - // sponge__BarycentricContext ctx, sponge_Vec2 p, - // sponge_Vec2 t0, - // sponge_Vec2 t1, - // sponge_Vec2 t2, - // float *u, float *v, float *w -// ) { - // sponge_Vec2 v2 = sponge_sub2(p, t0); - // float d20 = sponge_dot2(v2, ctx.v0); - // float d21 = sponge_dot2(v2, ctx.v1); - // float vr = (ctx.d11 * d20 - ctx.d01 * d21) / ctx.denom; - // float wr = (ctx.d00 * d21 - ctx.d01 * d20) / ctx.denom; - // float ur = 1.0f - vr - wr; - // *u = ur; - // *v = vr; - // *w = wr; -// } - -int sponge_texture_valid(sponge_Texture tex) { +int32_t sponge_texture_valid(sponge_Texture tex) { return tex.width != 0 && tex.height != 0 && tex.stride_pixels != 0; } @@ -278,62 +274,65 @@ void sponge_draw_texture(sponge_Texture c, sponge_Vec2I offset, sponge_Texture t } } -/* -void sponge_draw_triangle_col(sponge_Texture c, int32_t x0, int32_t y0, int32_t x1, int32_t y1, int32_t x2, int32_t y2, uint32_t color) { - sponge_draw_triangle_col3(c, x0, y0, x1, y1, x2, y2, color, color, color); +int32_t sponge_edge_function(sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I p) { + return ((p.x - v0.x) * (v1.y - v0.y)) - ((p.y - v0.y) * (v1.x - v0.x)); } -// NOTE(kard): -// this does not accept floats on purpose. -void sponge_draw_triangle_col3( - sponge_Texture c, int32_t x0, int32_t y0, int32_t x1, int32_t y1, int32_t x2, int32_t y2, - uint32_t color0, uint32_t color1, uint32_t color2) { - SPONGE_ASSERT(sponge_canvas_valid(c)); - - sponge_Vec2 t0 = { .x = (float)x0, .y = (float)y0 }; - sponge_Vec2 t1 = { .x = (float)x1, .y = (float)y1 }; - sponge_Vec2 t2 = { .x = (float)x2, .y = (float)y2 }; - - int32_t smin_x = SPONGE__MIN(x0, SPONGE__MIN(x1, x2)); - int32_t smax_x = SPONGE__MAX(x0, SPONGE__MAX(x1, x2)); - int32_t smin_y = SPONGE__MIN(y0, SPONGE__MIN(y1, y2)); - int32_t smax_y = SPONGE__MAX(y0, SPONGE__MAX(y1, y2)); - - uint32_t min_x = (uint32_t)SPONGE__CLAMP(smin_x, 0, (int32_t)(c.width - 1)); - uint32_t max_x = (uint32_t)SPONGE__CLAMP(smax_x, 0, (int32_t)(c.width - 1)); - uint32_t min_y = (uint32_t)SPONGE__CLAMP(smin_y, 0, (int32_t)(c.height - 1)); - uint32_t max_y = (uint32_t)SPONGE__CLAMP(smax_y, 0, (int32_t)(c.height - 1)); - +void sponge_draw_triangle_init( + sponge_Texture c, sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2, + sponge_Vec2I *out_min, sponge_Vec2I *out_max, float *out_area2 +) { + *out_min = sponge_vec2i_make( + SPONGE_MAX(0, SPONGE_MIN(SPONGE_MIN(v0.x, v1.x), v2.x)), + SPONGE_MAX(0, SPONGE_MIN(SPONGE_MIN(v0.y, v1.y), v2.y))); + *out_max = sponge_vec2i_make( + SPONGE_MIN((int32_t)c.width - 1, SPONGE_MAX(SPONGE_MAX(v0.x, v1.x), v2.x)), + SPONGE_MIN((int32_t)c.height - 1, SPONGE_MAX(SPONGE_MAX(v0.y, v1.y), v2.y))); + if (out_area2) { + *out_area2 = (float)sponge_edge_function(v0, v1, v2); + } +} - uint32_t *row = c.pixels + (min_y * c.stride); +// non-zero if p inside triangle, outputs only valid if inside +int32_t sponge_draw_triangle_iter( + sponge_Vec2I p, sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2, float area2, + float *out_w0, float *out_w1, float *out_w2 +) { + int32_t w0 = sponge_edge_function(v1, v2, p); + int32_t w1 = sponge_edge_function(v2, v0, p); + int32_t w2 = sponge_edge_function(v0, v1, p); + // NOTE(kard): this is <= not >= because our y goes down not up, and we want clockwise winding + if (w0 <= 0 && w1 <= 0 && w2 <= 0) { + *out_w0 = (float)w0 / area2; + *out_w1 = (float)w1 / area2; + *out_w2 = (float)w2 / area2; + return 1; + } + return 0; +} - sponge__ColorF color0f = sponge__colf_unpack(color0); - sponge__ColorF color1f = sponge__colf_unpack(color1); - sponge__ColorF color2f = sponge__colf_unpack(color2); +void sponge_draw_triangle_col3( + sponge_Texture c, + sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2, + sponge_ColorF col0, sponge_ColorF col1, sponge_ColorF col2 +) { + sponge_Vec2I min, max; + float area2; + sponge_draw_triangle_init(c, v0, v1, v2, &min, &max, &area2); + sponge_Color32 *row = c.pixels + (min.y * c.stride_pixels); - for (uint32_t y = min_y; y <= max_y; y++, row += c.stride) { - for (uint32_t x = x0; x <= max_x; x++) { - float u, v, w; - sponge_Vec2 p = { .x = (float)x, .y = (float)y }; - sponge__BarycentricContext ctx = sponge__barycentric_init(t0, t1, t2); - sponge__barycentric(ctx, p, t0, t1, t2, &u, &v, &w); - if (u > 0.0f && v > 0.0f && w > 0.0f) - { - sponge__ColorF c0 = sponge__colf_mul(color0f, u); - sponge__ColorF c1 = sponge__colf_mul(color1f, v); - sponge__ColorF c2 = sponge__colf_mul(color2f, w); - sponge__ColorF result = sponge__colf_add(c0, sponge__colf_add(c1, c2)); - row[x] = sponge__colf_pack(result); + for (int32_t y = min.y; y <= max.y; y++, row += c.stride_pixels) { + for (int32_t x = min.x; x <= max.x; x++) { + float w0, w1, w2; + if (sponge_draw_triangle_iter(sponge_vec2i_make(x, y), v0, v1, v2, area2, &w0, &w1, &w2)) { + sponge_ColorF result = sponge_vec4_make(0.0f, 0.0f, 0.0f, 0.0f); + result = sponge_vec4_add(result, sponge_vec4_mul(col0, w0)); + result = sponge_vec4_add(result, sponge_vec4_mul(col1, w1)); + result = sponge_vec4_add(result, sponge_vec4_mul(col2, w2)); + row[x] = sponge_colorf_to_color32(result); } } } } -void sponge_draw_triangle_uv( - sponge_Texture c, int32_t x0, int32_t y0, int32_t x1, int32_t y1, int32_t x2, int32_t y2, - uint32_t color0, uint32_t color1, uint32_t color2, - sponge_Vec2 uv0, sponge_Vec2 uv1, sponge_Vec2 uv2, sponge_Texture tex) { -} -*/ - #endif // SPONGE_IMPLEMENTATION |