diff --git a/src/gba/renderers/gl.c b/src/gba/renderers/gl.c
index 4a751c706..e4d6415d6 100644
--- a/src/gba/renderers/gl.c
+++ b/src/gba/renderers/gl.c
@@ -233,6 +233,29 @@ static const char* const _interpolate =
 	"	aff[2] = transform[start + 2].zw;\n"
 	"	mat[3] = transform[start + 3].xy;\n"
 	"	aff[3] = transform[start + 3].zw;\n"
+	"}\n"
+
+	"ivec2 affineInterpolate() {\n"
+	"	ivec2 mat[4];\n"
+	"	ivec2 offset[4];\n"
+	"	vec2 incoord = texCoord;\n"
+	"	if (mosaic.x > 1) {\n"
+	"		incoord.x = float(MOSAIC(incoord.x, mosaic.x));\n"
+	"	}\n"
+	"	if (mosaic.y > 1) {\n"
+	"		incoord.y = float(MOSAIC(incoord.y, mosaic.y));\n"
+	"	}\n"
+	"	loadAffine(int(incoord.y), mat, offset);\n"
+	"	float y = fract(incoord.y);\n"
+	"	float start = 2. / 3.;\n"
+	"	if (int(incoord.y) - range.x < 4) {\n"
+	"		y = incoord.y - float(range.x);\n"
+	"		start -= 1.;\n"
+	"	}\n"
+	"	float lin = start + y / 3.;\n"
+	"	vec2 mixedTransform = interpolate(mat, lin);\n"
+	"	vec2 mixedOffset = interpolate(offset, lin);\n"
+	"	return ivec2(mixedTransform * incoord.x + mixedOffset);\n"
 	"}\n";
 
 static const char* const _renderMode2 =
@@ -250,8 +273,7 @@ static const char* const _renderMode2 =
 	"OUT(0) out vec4 color;\n"
 
 	"int fetchTile(ivec2 coord);\n"
-	"vec2 interpolate(ivec2 arr[4], float x);\n"
-	"void loadAffine(int y, out ivec2 mat[4], out ivec2 aff[4]);\n"
+	"ivec2 affineInterpolate();\n"
 
 	"int renderTile(ivec2 coord) {\n"
 	"	int map = (coord.x >> 11) + (((coord.y >> 7) & 0x7F0) << size);\n"
@@ -278,26 +300,7 @@ static const char* const _renderMode2 =
 	"}\n"
 
 	"void main() {\n"
-	"	ivec2 mat[4];\n"
-	"	ivec2 offset[4];\n"
-	"	vec2 incoord = texCoord;\n"
-	"	if (mosaic.x > 1) {\n"
-	"		incoord.x = float(MOSAIC(incoord.x, mosaic.x));\n"
-	"	}\n"
-	"	if (mosaic.y > 1) {\n"
-	"		incoord.y = float(MOSAIC(incoord.y, mosaic.y));\n"
-	"	}\n"
-	"	loadAffine(int(incoord.y), mat, offset);\n"
-	"	float y = fract(incoord.y);\n"
-	"	float start = 2. / 3.;\n"
-	"	if (int(incoord.y) - range.x < 4) {\n"
-	"		y = incoord.y - float(range.x);\n"
-	"		start -= 1.;\n"
-	"	}\n"
-	"	float lin = start + y / 3.;\n"
-	"	vec2 mixedTransform = interpolate(mat, lin);\n"
-	"	vec2 mixedOffset = interpolate(offset, lin);\n"
-	"	int paletteEntry = fetchTile(ivec2(mixedTransform * incoord.x + mixedOffset));\n"
+	"	int paletteEntry = fetchTile(affineInterpolate());\n"
 	"	color = texelFetch(palette, ivec2(paletteEntry, int(texCoord.y)), 0);\n"
 	"}";
 
@@ -325,30 +328,10 @@ static const char* const _renderMode35 =
 	"uniform ivec2 mosaic;\n"
 	"OUT(0) out vec4 color;\n"
 
-	"vec2 interpolate(ivec2 arr[4], float x);\n"
-	"void loadAffine(int y, out ivec2 mat[4], out ivec2 aff[4]);\n"
+	"ivec2 affineInterpolate();\n"
 
 	"void main() {\n"
-	"	ivec2 mat[4];\n"
-	"	ivec2 offset[4];\n"
-	"	vec2 incoord = texCoord;\n"
-	"	if (mosaic.x > 1) {\n"
-	"		incoord.x = float(MOSAIC(incoord.x, mosaic.x));\n"
-	"	}\n"
-	"	if (mosaic.y > 1) {\n"
-	"		incoord.y = float(MOSAIC(incoord.y, mosaic.y));\n"
-	"	}\n"
-	"	loadAffine(int(incoord.y), mat, offset);\n"
-	"	float y = fract(incoord.y);\n"
-	"	float start = 2. / 3.;\n"
-	"	if (int(incoord.y) - range.x < 4) {\n"
-	"		y = incoord.y - float(range.x);\n"
-	"		start -= 1.;\n"
-	"	}\n"
-	"	float lin = start + y / 3.;\n"
-	"	vec2 mixedTransform = interpolate(mat, lin);\n"
-	"	vec2 mixedOffset = interpolate(offset, lin);\n"
-	"	ivec2 coord = ivec2(mixedTransform * incoord.x + mixedOffset);\n"
+	"	ivec2 coord = affineInterpolate();\n"
 	"	if (coord.x < 0 || coord.x >= (size.x << 8)) {\n"
 	"		discard;\n"
 	"	}\n"
@@ -386,30 +369,10 @@ static const char* const _renderMode4 =
 	"uniform ivec2 mosaic;\n"
 	"OUT(0) out vec4 color;\n"
 
-	"vec2 interpolate(ivec2 arr[4], float x);\n"
-	"void loadAffine(int y, out ivec2 mat[4], out ivec2 aff[4]);\n"
+	"ivec2 affineInterpolate();\n"
 
 	"void main() {\n"
-	"	ivec2 mat[4];\n"
-	"	ivec2 offset[4];\n"
-	"	vec2 incoord = texCoord;\n"
-	"	if (mosaic.x > 1) {\n"
-	"		incoord.x = float(MOSAIC(incoord.x, mosaic.x));\n"
-	"	}\n"
-	"	if (mosaic.y > 1) {\n"
-	"		incoord.y = float(MOSAIC(incoord.y, mosaic.y));\n"
-	"	}\n"
-	"	loadAffine(int(incoord.y), mat, offset);\n"
-	"	float y = fract(incoord.y);\n"
-	"	float start = 2. / 3.;\n"
-	"	if (int(incoord.y) - range.x < 4) {\n"
-	"		y = incoord.y - float(range.x);\n"
-	"		start -= 1.;\n"
-	"	}\n"
-	"	float lin = start + y / 3.;\n"
-	"	vec2 mixedTransform = interpolate(mat, lin);\n"
-	"	vec2 mixedOffset = interpolate(offset, lin);\n"
-	"	ivec2 coord = ivec2(mixedTransform * incoord.x + mixedOffset);\n"
+	"	ivec2 coord = affineInterpolate();\n"
 	"	if (coord.x < 0 || coord.x >= (size.x << 8)) {\n"
 	"		discard;\n"
 	"	}\n"