Default shaders use lovrmain;

etc/shaders/cubemap.frag

@@ -5,8 +5,7 @@
 #include "lovr.glsl"
 
 layout(set = 1, binding = 1) uniform textureCube SkyboxTexture;
-layout(location = 0) in vec3 Direction;
 
-void main() {
-  PixelColors[0] = Color * getPixel(SkyboxTexture, Direction);
+vec4 lovrmain() {
+  return Color * getPixel(SkyboxTexture, Normal);
 }

etc/shaders/cubemap.vert

@@ -4,11 +4,7 @@
 
 #include "lovr.glsl"
 
-layout(location = 0) out vec3 Direction;
-
-void main() {
-  Color = PassColor * VertexColor;
-
+vec4 lovrmain() {
   const vec2 uvs[6] = vec2[6](
     vec2(-1, -1),
     vec2(-1, +1),
@@ -21,6 +17,6 @@ void main() {
   vec2 uv = uvs[VertexIndex % 6];
   vec3 ray = vec3(uv, -1.);
   mat3 inverseViewOrientation = transpose(mat3(View));
-  Direction = normalize(inverseViewOrientation * (InverseProjection * vec4(ray, 1.)).xyz);
-  Position = vec4(uv, 0, 1);
+  Normal = normalize(inverseViewOrientation * (InverseProjection * vec4(ray, 1.)).xyz);
+  return vec4(uv, 0, 1);
 }

etc/shaders/equirect.frag

@@ -2,16 +2,16 @@
 #extension GL_EXT_multiview : require
 #extension GL_GOOGLE_include_directive : require
 
-#define PI 3.141592653589793238462643383
-
 #include "lovr.glsl"
 
+#define PI 3.141592653589793238462643383
+
 layout(location = 0) in vec3 Direction;
 
-void main() {
+vec4 lovrmain() {
   vec3 dir = normalize(Direction);
   float phi = acos(dir.y);
   float theta = atan(dir.x, -dir.z);
   vec2 uv = vec2(.5 + theta / (2 * PI), phi / PI);
-  PixelColors[0] = Color * getPixel(ColorTexture, uv);
+  return Color * getPixel(ColorTexture, uv);
 }

etc/shaders/fill.vert

@@ -4,11 +4,9 @@
 
 #include "lovr.glsl"
 
-void main() {
-  Color = PassColor * VertexColor;
+vec4 lovrmain() {
   float x = -1 + float((VertexIndex & 1) << 2);
   float y = -1 + float((VertexIndex & 2) << 1);
   UV = vec2(x, y) * .5 + .5;
-  Position = vec4(x, y, 1., 1.);
-  PointSize = 1.f;
+  return vec4(x, y, 1., 1.);
 }

etc/shaders/font.frag

@@ -14,11 +14,11 @@ float median(float r, float g, float b) {
   return max(min(r, g), min(max(r, g), b));
 }
 
-void main() {
+vec4 lovrmain() {
   vec3 msdf = getPixel(ColorTexture).rgb;
   float sdf = median(msdf.r, msdf.g, msdf.b);
   float screenPxDistance = screenPxRange() * (sdf - .5);
   float alpha = clamp(screenPxDistance + .5, 0., 1.);
   if (alpha <= 0.) discard;
-  PixelColors[0] = vec4(Color.rgb, Color.a * alpha);
+  return vec4(Color.rgb, Color.a * alpha);
 }

etc/shaders/lovr.glsl

@@ -111,7 +111,7 @@ layout(location = 12) in vec2 UV;
 #define WorldFromLocal (Transform)
 
 #define DefaultPosition (ClipFromLocal * VertexPosition)
-#define DefaultColor (Color * MaterialColor * getPixel(ColorTexture))
+#define DefaultColor (Color * getPixel(ColorTexture))
 #endif
 
 #ifdef GL_FRAGMENT_SHADER
@@ -121,3 +121,31 @@ vec4 getPixel(texture3D t, vec3 uvw) { return texture(sampler3D(t, Sampler), uvw
 vec4 getPixel(textureCube t, vec3 dir) { return texture(samplerCube(t, Sampler), dir); }
 vec4 getPixel(texture2DArray t, vec3 uvw) { return texture(sampler2DArray(t, Sampler), uvw); }
 #endif
+
+// Entrypoints
+#ifndef NO_DEFAULT_MAIN
+#ifdef GL_VERTEX_SHADER
+vec4 lovrmain();
+void main() {
+  Color = VertexColor * MaterialColor * PassColor;
+  Normal = NormalMatrix * VertexNormal;
+  UV = VertexUV;
+  PointSize = 1.f;
+  Position = lovrmain();
+}
+#endif
+
+#ifdef GL_FRAGMENT_SHADER
+vec4 lovrmain();
+void main() {
+  PixelColors[0] = lovrmain();
+}
+#endif
+
+#ifdef GL_COMPUTE_SHADER
+vec4 lovrmain();
+void main() {
+  lovrmain();
+}
+#endif
+#endif

etc/shaders/unlit.frag

@@ -4,6 +4,6 @@
 
 #include "lovr.glsl"
 
-void main() {
-  PixelColors[0] = Color * MaterialColor * getPixel(ColorTexture, UV);
+vec4 lovrmain() {
+  return DefaultColor;
 }

etc/shaders/unlit.vert

@@ -4,10 +4,6 @@
 
 #include "lovr.glsl"
 
-void main() {
-  Color = PassColor * VertexColor;
-  Normal = normalize(NormalMatrix * VertexNormal);
-  UV = VertexUV;
-  Position = DefaultPosition;
-  PointSize = 1.f;
+vec4 lovrmain() {
+  return DefaultPosition;
 }

src/modules/graphics/graphics.c

@@ -1333,32 +1333,18 @@ ShaderSource lovrGraphicsCompileShader(ShaderStage stage, ShaderSource* source)
     "#extension GL_EXT_multiview : require\n"
     "#extension GL_GOOGLE_include_directive : require\n";
 
-  const char* suffixes[] = {
-    [STAGE_VERTEX] = ""
-      "void main() {"
-        "Color = PassColor * VertexColor;"
-        "Normal = NormalMatrix * VertexNormal;"
-        "UV = VertexUV;"
-        "Position = lovrmain();"
-      "}",
-    [STAGE_FRAGMENT] = "void main() { PixelColors[0] = lovrmain(); }",
-    [STAGE_COMPUTE] = "void main() { lovrmain(); }"
-  };
-
   const char* strings[] = {
     prefix,
     (const char*) etc_shaders_lovr_glsl,
     "#line 1\n",
-    source->code,
-    suffixes[stage]
+    source->code
   };
 
   int lengths[] = {
     -1,
     etc_shaders_lovr_glsl_len,
     -1,
-    source->size,
-    -1
+    source->size
   };
 
   const glslang_resource_t* resource = glslang_default_resource();