From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sun, 23 Mar 2014 11:17:42 +0000 (+0100)
Subject: Add some skeleton code for using GL_ARB_debug_output (disabled by default).
X-Git-Tag: 1.1~12^2~2^2
X-Git-Url: https://git.sesse.net/?p=movit;a=commitdiff_plain;h=fe36cdba16b02cab582f2d0516e98fcdb62f3807

Add some skeleton code for using GL_ARB_debug_output (disabled by default).
---

diff --git a/demo.cpp b/demo.cpp
index c9b46ea..ba96291 100644
--- a/demo.cpp
+++ b/demo.cpp
@@ -191,6 +191,7 @@ int main(int argc, char **argv)
 	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
 
 #ifdef HAVE_SDL2
+	// SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);
 	SDL_Window *window = SDL_CreateWindow("OpenGL window",
 		SDL_WINDOWPOS_UNDEFINED,
 		SDL_WINDOWPOS_UNDEFINED,
diff --git a/gtest_sdl_main.cpp b/gtest_sdl_main.cpp
index cd68777..90a929e 100644
--- a/gtest_sdl_main.cpp
+++ b/gtest_sdl_main.cpp
@@ -34,6 +34,10 @@ int main(int argc, char **argv) {
 //	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK, SDL_GL_CONTEXT_PROFILE_CORE);
 //	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
 //	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
+
+	// See also init.cpp for how to enable debugging.
+//	SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);
+
 	SDL_Window *window = SDL_CreateWindow("OpenGL window for unit test",
 		SDL_WINDOWPOS_UNDEFINED,
 		SDL_WINDOWPOS_UNDEFINED,
diff --git a/init.cpp b/init.cpp
index 4802c68..b4e69b0 100644
--- a/init.cpp
+++ b/init.cpp
@@ -362,6 +362,17 @@ double get_glsl_version()
 	return glsl_version;
 }
 
+void APIENTRY debug_callback(GLenum source,
+                             GLenum type,
+                             GLuint id,
+                             GLenum severity,
+                             GLsizei length,
+                             const char *message,
+                             const void *userParam)
+{
+	printf("Debug: %s\n", message);
+}
+
 }  // namespace
 
 bool init_movit(const string& data_directory, MovitDebugLevel debug_level)
@@ -378,6 +389,12 @@ bool init_movit(const string& data_directory, MovitDebugLevel debug_level)
 	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 	glDisable(GL_DITHER);
 
+	// You can turn this on if you want detailed debug messages from the driver.
+	// You should probably also ask for a debug context (see gtest_sdl_main.cpp),
+	// or you might not get much data back.
+	// glDebugMessageCallbackARB(callback, NULL);
+	// glDebugMessageControlARB(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, 0, GL_TRUE);
+
 	if (!check_extensions()) {
 		return false;
 	}