From 8af35e5ed10f1b4cbef908948355a2832ea36fbe Mon Sep 17 00:00:00 2001 From: kkard2 Date: Sun, 14 Sep 2025 13:04:56 +0200 Subject: uv --- sponge.h | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) (limited to 'sponge.h') diff --git a/sponge.h b/sponge.h index d1a6b66..5484711 100644 --- a/sponge.h +++ b/sponge.h @@ -60,6 +60,7 @@ sponge_Vec2I sponge_vec2i_make(int32_t x, int32_t y); sponge_Vec2 sponge_vec2_add(sponge_Vec2 v0, sponge_Vec2 v1); sponge_Vec2 sponge_vec2_sub(sponge_Vec2 v0, sponge_Vec2 v1); +sponge_Vec2 sponge_vec2_mul(sponge_Vec2 v0, float f); float sponge_vec2_dot(sponge_Vec2 v0, sponge_Vec2 v1); sponge_Vec4 sponge_vec4_add(sponge_Vec4 v0, sponge_Vec4 v1); @@ -79,6 +80,8 @@ 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); +sponge_Color32 sponge_sample_texture(sponge_Vec2 uv, sponge_Texture tex); + // 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); @@ -96,6 +99,10 @@ 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); +void sponge_draw_triangle_uv( + sponge_Texture c, + sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2, + sponge_Vec2 uv0, sponge_Vec2 uv1, sponge_Vec2 uv2, sponge_Texture tex); #define SPONGE_CLAMP(val, min, max) ((val) < (min) ? (min) : ((val) > (max) ? (max) : (val))) #define SPONGE_MIN(x, y) ((x) < (y) ? (x) : (y)) @@ -166,6 +173,9 @@ sponge_Vec2 sponge_vec2_add(sponge_Vec2 v0, sponge_Vec2 v1) { sponge_Vec2 sponge_vec2_sub(sponge_Vec2 v0, sponge_Vec2 v1) { return (sponge_Vec2){ .x = v0.x - v1.x, .y = v0.y - v1.y }; } +sponge_Vec2 sponge_vec2_mul(sponge_Vec2 v0, float f) { + return (sponge_Vec2){ .x = v0.x * f, .y = v0.y * f }; +} float sponge_vec2_dot(sponge_Vec2 v0, sponge_Vec2 v1) { return (v0.x * v1.x) + (v0.y * v1.y); } @@ -274,6 +284,13 @@ void sponge_draw_texture(sponge_Texture c, sponge_Vec2I offset, sponge_Texture t } } +sponge_Color32 sponge_sample_texture(sponge_Vec2 uv, sponge_Texture tex) { + SPONGE_ASSERT(sponge_texture_valid(tex)); + uint32_t x = SPONGE_CLAMP((uint32_t)((float)tex.width * uv.x), 0, tex.width - 1); + uint32_t y = SPONGE_CLAMP((uint32_t)((float)tex.height * uv.y), 0, tex.height - 1); + return tex.pixels[(y * tex.stride_pixels) + x]; +} + 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)); } @@ -282,6 +299,7 @@ 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 ) { + SPONGE_ASSERT(sponge_texture_valid(c)); *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))); @@ -335,4 +353,28 @@ void sponge_draw_triangle_col3( } } +void sponge_draw_triangle_uv( + sponge_Texture c, + sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2, + sponge_Vec2 uv0, sponge_Vec2 uv1, sponge_Vec2 uv2, sponge_Texture tex +) { + 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 (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_Vec2 uv = sponge_vec2_make(0.0f, 0.0f); + uv = sponge_vec2_add(uv, sponge_vec2_mul(uv0, w0)); + uv = sponge_vec2_add(uv, sponge_vec2_mul(uv1, w1)); + uv = sponge_vec2_add(uv, sponge_vec2_mul(uv2, w2)); + row[x] = sponge_sample_texture(uv, tex); + } + } + } +} + #endif // SPONGE_IMPLEMENTATION -- cgit v1.3.1