From 1abb1f39f5512b50046f8932d2b0156af94a8885 Mon Sep 17 00:00:00 2001
From: UnknownShadow200 <unknownshadow200@gmail.com>
Date: Tue, 1 Apr 2025 21:29:00 +1100
Subject: [PATCH] OpenGL2: Avoid a division/reciprocal for linear fog
 calculation

---
 src/Graphics_GL2.c       | 4 ++--
 src/MapRenderer.c        | 3 +--
 src/Platform_Dreamcast.c | 3 ++-
 3 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/Graphics_GL2.c b/src/Graphics_GL2.c
index 359bfdd37..a9aa8087f 100644
--- a/src/Graphics_GL2.c
+++ b/src/Graphics_GL2.c
@@ -266,7 +266,7 @@ static void GenFragmentShader(const struct GLShader* shader, cc_string* dst) {
 	else    String_AppendConst(dst, "  vec4 col = out_col;\n");
 	if (al) String_AppendConst(dst, "  if (col.a < 0.5) discard;\n");
 	if (fm) String_AppendConst(dst, "  float depth = 1.0 / gl_FragCoord.w;\n");
-	if (fl) String_AppendConst(dst, "  float f = clamp((fogEnd - depth) / fogEnd, 0.0, 1.0);\n");
+	if (fl) String_AppendConst(dst, "  float f = clamp(1.0 - depth * fogEnd, 0.0, 1.0);\n");
 	if (fd) String_AppendConst(dst, "  float f = clamp(exp(fogDensity * depth), 0.0, 1.0);\n");
 	if (fm) String_AppendConst(dst, "  col.rgb = mix(fogCol, col.rgb, f);\n");
 	
@@ -402,7 +402,7 @@ static void ReloadUniforms(void) {
 		s->uniforms &= ~UNI_FOG_COL;
 	}
 	if ((s->uniforms & UNI_FOG_END) && (s->features & FTR_LINEAR_FOG)) {
-		glUniform1f(s->locations[3], gfx_fogEnd);
+		glUniform1f(s->locations[3], 1.0f / gfx_fogEnd);
 		s->uniforms &= ~UNI_FOG_END;
 	}
 	if ((s->uniforms & UNI_FOG_DENS) && (s->features & FTR_DENSIT_FOG)) {
diff --git a/src/MapRenderer.c b/src/MapRenderer.c
index 6c88d6a50..992563bbd 100644
--- a/src/MapRenderer.c
+++ b/src/MapRenderer.c
@@ -490,7 +490,6 @@ void MapRenderer_Refresh(void) {
 
 	if (mapChunks && World.Blocks) {
 		DeleteChunks();
-		RefreshChunks();
 
 		oldCount = MapRenderer_1DUsedCount;
 		MapRenderer_1DUsedCount = MapRenderer_UsedAtlases();
@@ -750,7 +749,7 @@ static void OnTerrainAtlasChanged(void* obj) {
 }
 
 static void OnBlockDefinitionChanged(void* obj) {
-	RefreshChunks();
+	MapRenderer_Refresh();
 	MapRenderer_1DUsedCount = MapRenderer_UsedAtlases();
 	ResetPartFlags();
 }
diff --git a/src/Platform_Dreamcast.c b/src/Platform_Dreamcast.c
index 99252e130..81e5903b4 100644
--- a/src/Platform_Dreamcast.c
+++ b/src/Platform_Dreamcast.c
@@ -740,4 +740,5 @@ static cc_result GetMachineID(cc_uint32* key) {
 	Mem_Copy(key, MACHINE_KEY, sizeof(MACHINE_KEY) - 1);
 	return 0;
 }
-#endif
\ No newline at end of file
+#endif
+