REVIEWED: RPI instancing checks #1679

src/rlgl.h

@@ -892,11 +892,15 @@ static PFNGLGENVERTEXARRAYSOESPROC glGenVertexArrays = NULL;
 static PFNGLBINDVERTEXARRAYOESPROC glBindVertexArray = NULL;
 static PFNGLDELETEVERTEXARRAYSOESPROC glDeleteVertexArrays = NULL;
 
+// It seems OpenGL ES 2.0 instancing entry points are not defined
+// in Raspberry Pi provided headers (despite being defined in official Khronos GLES2 headers)
+#if !defined(PLATFORM_RPI) && !defined(PLATFORM_DRM)
 // NOTE: Instancing functionality could also be available through extension
 static PFNGLDRAWARRAYSINSTANCEDEXTPROC glDrawArraysInstanced = NULL;
 static PFNGLDRAWELEMENTSINSTANCEDEXTPROC glDrawElementsInstanced = NULL;
 static PFNGLVERTEXATTRIBDIVISOREXTPROC glVertexAttribDivisor = NULL;
 #endif
+#endif
 
 //----------------------------------------------------------------------------------
 // Module specific Functions Declaration
@@ -1722,7 +1726,7 @@ void rlglInit(int width, int height)
         }
 
         // Check instanced rendering support
-        if (strcmp(extList[i], (const char *)"GL_ANGLE_instanced_arrays") == 0)
+        if (strcmp(extList[i], (const char *)"GL_ANGLE_instanced_arrays") == 0)         // Web ANGLE
         {
             glDrawArraysInstanced = (PFNGLDRAWARRAYSINSTANCEDEXTPROC)eglGetProcAddress("glDrawArraysInstancedANGLE");
             glDrawElementsInstanced = (PFNGLDRAWELEMENTSINSTANCEDEXTPROC)eglGetProcAddress("glDrawElementsInstancedANGLE");
@@ -1730,6 +1734,18 @@ void rlglInit(int width, int height)
 
             if ((glDrawArraysInstanced != NULL) && (glDrawElementsInstanced != NULL) && (glVertexAttribDivisor != NULL)) RLGL.ExtSupported.instancing = true;
         }
+        else
+        {
+            if ((strcmp(extList[i], (const char *)"GL_EXT_draw_instanced") == 0) &&     // Standard EXT
+                (strcmp(extList[i], (const char *)"GL_EXT_instanced_arrays") == 0))
+            {
+                glDrawArraysInstanced = (PFNGLDRAWARRAYSINSTANCEDEXTPROC)eglGetProcAddress("glDrawArraysInstancedEXT");
+                glDrawElementsInstanced = (PFNGLDRAWELEMENTSINSTANCEDEXTPROC)eglGetProcAddress("glDrawElementsInstancedEXT");
+                glVertexAttribDivisor = (PFNGLVERTEXATTRIBDIVISOREXTPROC)eglGetProcAddress("glVertexAttribDivisorEXT");
+
+                if ((glDrawArraysInstanced != NULL) && (glDrawElementsInstanced != NULL) && (glVertexAttribDivisor != NULL)) RLGL.ExtSupported.instancing = true;
+            }
+        }
 
         // Check NPOT textures support
         // NOTE: Only check on OpenGL ES, OpenGL 3.3 has NPOT textures full support as core feature