Mercurial > hg > ascension / changeset

--- a/src/ascension/datatypes.h	Thu Jun 26 21:43:22 2025 +0200
+++ b/src/ascension/datatypes.h	Fri Jun 27 22:30:17 2025 +0200
@@ -164,13 +164,13 @@
 
 static inline asc_col4f asc_col_itof(asc_col4i c) {
     // dividing by 256 is much more performant
-    // TODO: this loses optimized rendering for zero-color / alpha
-    return (asc_col4f) {
-        (c.red+1.f) / 256.f,
-        (c.green+1.f) / 256.f,
-        (c.blue+1.f) / 256.f,
-        (c.alpha+1.f) / 256.f,
-    };
+    // because it compiles to multiplication instead of division
+    const float f = 256.f / 255.f;
+    const float red = c.red * f / 256.f;
+    const float green = c.green * f / 256.f;
+    const float blue = c.blue * f / 256.f;
+    const float alpha = c.alpha * f / 256.f;
+    return (asc_col4f) {red, green, blue, alpha};
 }
 
 static inline SDL_Color asc_col_sdl(asc_col4i col) {