M CHANGES → CHANGES

@@ -49,6 +49,7 @@ - GBA Video: Fix rare regression blending semitransparent sprites (fixes mgba.io/i/1876)
  - GBA Video: Emulate sprite cycle limits in OpenGL renderer (fixes mgba.io/i/1635)
  - GBA Video: Do not affect OBJ pixel priority when writing OBJWIN (fixes mgba.io/i/1890)
  - GBA Video: Fix deferred blending when OBJWIN matches window (fixes mgba.io/i/1905)
+ - GBA Video: Fix mode 4 transparency in OpenGL (fixes mgba.io/i/1907)
  - SM83: Emulate HALT bug
 Other fixes:
  - 3DS: Redo video sync to be more precise

M src/gba/renderers/gl.c → src/gba/renderers/gl.c

@@ -391,7 +391,11 @@ "		discard;\n"
 	"	}\n"
 	"	int address = charBase + (coord.x >> 8) + (coord.y >> 8) * size.x;\n"
 	"	int twoEntries = texelFetch(vram, ivec2((address >> 1) & 255, address >> 9), 0).r;\n"
-	"	int paletteEntry = palette[(twoEntries >> (8 * (address & 1)) & 255)];\n"
+	"	int entry = (twoEntries >> (8 * (address & 1))) & 255;\n"
+	"	if (entry == 0) {\n"
+	"		discard;\n"
+	"	}\n"
+	"	int paletteEntry = palette[entry];\n"
 	"	color = vec4(PALETTE_ENTRY(paletteEntry), 1.);\n"
 	"}";