Global gamma correction

1 files changed, 46 insertions, 39 deletions

diff --git a/graphics.c b/graphics.c
index f4bc699..3552792 100644
--- a/graphics.c
+++ b/graphics.c
@@ -50,13 +50,7 @@ vec4_f32 vec4_f32_lerp     (vec4_f32 a, vec4_f32 b, f32 t);
 
 //  ================================================================
 
-typedef struct {
-  //  NOTE: Dimensions are in pixels.
-  i64       width;
-  i64       height;
-  i64       stride;
-  vec4_f32 *pixels;
-} Pixel_Buffer;
+//  NOTE: Dimensions are in pixels.
 
 typedef struct {
   f64 x;
@@ -65,6 +59,31 @@ typedef struct {
   f64 height;
 } Box;
 
+//  TODO:
+// typedef struct {
+//   b8  enabled;
+//   i64 x;
+//   i64 y;
+//   i64 width;
+//   i64 height;
+// } Bounding_Box;
+
+typedef struct {
+  i64 width;
+  i64 height;
+  i64 stride;
+  // Bounding_Box bounds;
+  u8 *pixels;
+} Stencil_Buffer;
+
+typedef struct {
+  i64       width;
+  i64       height;
+  i64       stride;
+  // Bounding_Box bounds;
+  vec4_f32 *pixels;
+} Pixel_Buffer;
+
 enum {
   GRAPHICS_DRAW_PIXELS,
   GRAPHICS_FILL_RECTANGLE,
@@ -981,49 +1000,37 @@ vec4_f32 vec4_f32_lerp(vec4_f32 a, vec4_f32 b, f32 t) {
 
 //  ================================================================
 
-static f64 gamma_(f64 x) {
-  if (x >= 0.0031308)
-    return 1.055 * pow(x, 1.0 / 2.4) - 0.055;
-  return 12.92 * x;
-}
-
-static f64 gamma_re_(f64 x) {
-  if (x >= 0.04045)
-    return pow((x + 0.055) / 1.055, 2.4);
-  return x / 12.92;
-}
-
 vec3_f32 rgb_gamma_add(vec3_f32 rgb) {
   return (vec3_f32) {
-    .x = (f32) gamma_(rgb.x),
-    .y = (f32) gamma_(rgb.y),
-    .z = (f32) gamma_(rgb.z),
+    .x = gamma_(rgb.x),
+    .y = gamma_(rgb.y),
+    .z = gamma_(rgb.z),
   };
 }
 
 vec3_f32 rgb_gamma_remove(vec3_f32 rgb) {
   return (vec3_f32) {
-    .x = (f32) gamma_re_(rgb.x),
-    .y = (f32) gamma_re_(rgb.y),
-    .z = (f32) gamma_re_(rgb.z),
+    .x = gamma_re_(rgb.x),
+    .y = gamma_re_(rgb.y),
+    .z = gamma_re_(rgb.z),
   };
 }
 
 vec4_f32 rgba_gamma_add(vec4_f32 rgba) {
   return (vec4_f32) {
-    .x = (f32) gamma_(rgba.x),
-    .y = (f32) gamma_(rgba.y),
-    .z = (f32) gamma_(rgba.z),
-    .w = (f32) gamma_(rgba.w),
+    .x = gamma_(rgba.x),
+    .y = gamma_(rgba.y),
+    .z = gamma_(rgba.z),
+    .w = gamma_(rgba.w),
   };
 }
 
 vec4_f32 rgba_gamma_remove(vec4_f32 rgba) {
   return (vec4_f32) {
-    .x = (f32) gamma_re_(rgba.x),
-    .y = (f32) gamma_re_(rgba.y),
-    .z = (f32) gamma_re_(rgba.z),
-    .w = (f32) gamma_re_(rgba.w),
+    .x = gamma_re_(rgba.x),
+    .y = gamma_re_(rgba.y),
+    .z = gamma_re_(rgba.z),
+    .w = gamma_re_(rgba.w),
   };
 }
 
@@ -2186,7 +2193,7 @@ TEST("colors") {
   vec3_f32 white = rgb_from_lch(lch_from_rgb((vec3_f32) { 1.f, 1.f, 1.f, }));
   REQUIRE_EQ(white.x * 100, 100);
   REQUIRE_EQ(white.y * 100, 100);
-  REQUIRE_EQ((white.z + 3e-7) * 100, 100);
+  REQUIRE_EQ((white.z + 6e-7) * 100, 100);
 
   vec3_f32 black = rgb_from_lch(lch_from_rgb((vec3_f32) { 0.f, 0.f, 0.f, }));
   REQUIRE_EQ(black.x * 100, 0);
@@ -2205,13 +2212,13 @@ TEST("colors") {
 
   vec3_f32 green = rgb_from_lch(lch_from_rgb((vec3_f32) { 0.f, 1.f, 0.f, }));
   REQUIRE_EQ(green.x * 100,   0);
-  REQUIRE_EQ(green.y * 100, 100);
+  REQUIRE_EQ((green.y + 3e-7) * 100, 100);
   REQUIRE_EQ(green.z * 100,   0);
 
   vec3_f32 blue = rgb_from_lch(lch_from_rgb((vec3_f32) { 0.f, 0.f, 1.f, }));
   REQUIRE_EQ(blue.x * 100, 0);
   REQUIRE_EQ(blue.y * 100, 0);
-  REQUIRE_EQ((blue.z + 6e-8) * 100, 100);
+  REQUIRE_EQ((blue.z + 3e-7) * 100, 100);
 
   vec3_f32 yellow = rgb_from_lch(lch_from_rgb((vec3_f32) { 1.f, 1.f, 0.f, }));
   REQUIRE_EQ(yellow.x * 100, 100);
@@ -2220,13 +2227,13 @@ TEST("colors") {
 
   vec3_f32 cyan = rgb_from_lch(lch_from_rgb((vec3_f32) { 0.f, 1.f, 1.f, }));
   REQUIRE_EQ(cyan.x * 100,   0);
-  REQUIRE_EQ((cyan.y + 2e-7) * 100, 100);
-  REQUIRE_EQ((cyan.z + 2e-7) * 100, 100);
+  REQUIRE_EQ((cyan.y + 3e-7) * 100, 100);
+  REQUIRE_EQ((cyan.z + 3e-7) * 100, 100);
 
   vec3_f32 purple = rgb_from_lch(lch_from_rgb((vec3_f32) { 1.f, 0.f, 1.f, }));
   REQUIRE_EQ(purple.x * 100, 100);
   REQUIRE_EQ(purple.y * 100, 0);
-  REQUIRE_EQ((purple.z + 2e-7) * 100, 100);
+  REQUIRE_EQ((purple.z + 3e-7) * 100, 100);
 }
 
 TEST("rectangle corners") {