From 66eb00414726786f46d98727e26c74f0b12fe27c Mon Sep 17 00:00:00 2001
From: Nick Kreeger <nick.kreeger@gmail.com>
Date: Thu, 25 Jul 2019 21:58:58 -0700
Subject: [PATCH] save

---
 binding/egl_context_wrapper.cc     |  6 ++++++
 binding/egl_context_wrapper.h      |  6 ++++++
 binding/webgl_rendering_context.cc | 16 ++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/binding/egl_context_wrapper.cc b/binding/egl_context_wrapper.cc
index 37dccf1..6ddbdfa 100644
--- a/binding/egl_context_wrapper.cc
+++ b/binding/egl_context_wrapper.cc
@@ -440,6 +440,12 @@ void EGLContextWrapper::BindProcAddresses() {
   glViewport =
       reinterpret_cast<PFNGLVIEWPORTPROC>(eglGetProcAddress("glViewport"));
 
+#if DEBUG
+  // Debug specific
+  glDebugMessageCallback = reinterpret_cast<PFNGLDEBUGMESSAGECALLBACKPROC>(
+      eglGetProcAddress("glDebugMessageCallback"));
+#endif
+
   // ANGLE specific
   glRequestExtensionANGLE = reinterpret_cast<PFNGLREQUESTEXTENSIONANGLEPROC>(
       eglGetProcAddress("glRequestExtensionANGLE"));
diff --git a/binding/egl_context_wrapper.h b/binding/egl_context_wrapper.h
index 09b05f6..53ca0ba 100644
--- a/binding/egl_context_wrapper.h
+++ b/binding/egl_context_wrapper.h
@@ -27,6 +27,7 @@
 #include "angle/include/GLES2/gl2.h"
 #include "angle/include/GLES2/gl2ext.h"
 #include "angle/include/GLES3/gl3.h"
+#include "angle/include/GLES3/gl32.h"  // TODO - debug this?
 
 #include <iostream>
 #include <memory>
@@ -228,6 +229,11 @@ class EGLContextWrapper {
   PFNGLVERTEXATTRIBPOINTERPROC glVertexAttribPointer;
   PFNGLVIEWPORTPROC glViewport;
 
+#if DEBUG
+  // Debug specific
+  PFNGLDEBUGMESSAGECALLBACKPROC glDebugMessageCallback;
+#endif
+
   // ANGLE specific
   PFNGLREQUESTEXTENSIONANGLEPROC glRequestExtensionANGLE;
 
diff --git a/binding/webgl_rendering_context.cc b/binding/webgl_rendering_context.cc
index 3ff94f8..bf734ab 100644
--- a/binding/webgl_rendering_context.cc
+++ b/binding/webgl_rendering_context.cc
@@ -373,6 +373,17 @@ static napi_status GetArrayLikeBuffer(napi_env env, napi_value array_like_value,
   return napi_invalid_arg;
 }
 
+#if DEBUG
+void DebugMessageCallback(GLenum source, GLenum type, GLuint id,
+                          GLenum severity, GLsizei length,
+                          const GLchar *message, const void *userParam) {
+  fprintf(stderr,
+          "GL CALLBACK: %s type = 0x%x, severity = 0x%x, message = %s\n",
+          (type == GL_DEBUG_TYPE_ERROR ? "** GL ERROR **" : ""), type, severity,
+          message);
+}
+#endif
+
 napi_ref WebGLRenderingContext::constructor_ref_;
 
 WebGLRenderingContext::WebGLRenderingContext(napi_env env)
@@ -391,6 +402,11 @@ WebGLRenderingContext::WebGLRenderingContext(napi_env env)
     return;
   }
   alloc_count_ = 0;
+
+#if DEBUG
+  eglContextWrapper_->glEnable(GL_DEBUG_OUTPUT);
+  eglContextWrapper_->glDebugMessageCallback(DebugMessageCallback, 0);
+#endif
 }
 
 WebGLRenderingContext::~WebGLRenderingContext() {