Shader:hasAttribute;

src/api/l_graphics_shader.c

@@ -48,9 +48,26 @@ static int l_lovrShaderHasStage(lua_State* L) {
   return 1;
 }
 
+static int l_lovrShaderHasAttribute(lua_State* L) {
+  Shader* shader = luax_checktype(L, 1, Shader);
+  const char* name;
+  uint32_t location;
+  if (lua_type(L, 2) == LUA_TNUMBER) {
+    location = luax_checku32(L, 2);
+    name = NULL;
+  } else {
+    name = lua_tostring(L, 2);
+    location = 0;
+  }
+  bool present = lovrShaderHasAttribute(shader, name, location);
+  lua_pushboolean(L, present);
+  return 1;
+}
+
 const luaL_Reg lovrShader[] = {
   { "clone", l_lovrShaderClone },
   { "getType", l_lovrShaderGetType },
   { "hasStage", l_lovrShaderHasStage },
+  { "hasAttribute", l_lovrShaderHasAttribute },
   { NULL, NULL }
 };

src/modules/graphics/graphics.c

@@ -1722,6 +1722,17 @@ bool lovrShaderHasStage(Shader* shader, ShaderStage stage) {
   }
 }
 
+bool lovrShaderHasAttribute(Shader* shader, const char* name, uint32_t location) {
+  uint32_t hash = name ? (uint32_t) hash64(name, strlen(name)) : 0;
+  for (uint32_t i = 0; i < shader->attributeCount; i++) {
+    ShaderAttribute* attribute = &shader->attributes[i];
+    if (name ? (attribute->hash == hash) : (attribute->location == location)) {
+      return true;
+    }
+  }
+  return false;
+}
+
 // Material
 
 Material* lovrMaterialCreate(MaterialInfo* info) {

src/modules/graphics/graphics.h

@@ -290,6 +290,7 @@ Shader* lovrShaderClone(Shader* parent, ShaderFlag* flags, uint32_t count);
 void lovrShaderDestroy(void* ref);
 const ShaderInfo* lovrShaderGetInfo(Shader* shader);
 bool lovrShaderHasStage(Shader* shader, ShaderStage stage);
+bool lovrShaderHasAttribute(Shader* shader, const char* name, uint32_t location);
 
 // Material