gpu: implement GL debug context logging.

src/application/sdl-app.cpp

@@ -48,10 +48,18 @@ sdl::app_display::app_display(char const *title, ivec2 res)
         }
     }
 
-    /* This seems to fix the swap context bug.
-     * However, perfs warning have been may occur. */
+    // This seems to fix a bug we used to have at context swap. Maybe remove one day.
     SDL_GL_SetAttribute(SDL_GL_SHARE_WITH_CURRENT_CONTEXT, 1);
 
+#if 0
+    // Ask for GL 3.2 at least
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 2);
+#endif
+#if LOL_BUILD_DEBUG
+    SDL_GL_SetAttribute(SDL_GL_CONTEXT_FLAGS, SDL_GL_CONTEXT_DEBUG_FLAG);
+#endif
+
     int flags = SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE;
     if (window_size == ivec2(0))
         flags |= SDL_WINDOW_FULLSCREEN_DESKTOP;

src/gpu/debug.cpp

@@ -17,6 +17,94 @@
 namespace lol
 {
 
+static std::map<GLenum, char const *> gl_dbg_source_to_str
+{
+    { GL_DEBUG_SOURCE_API, "API" },
+    { GL_DEBUG_SOURCE_WINDOW_SYSTEM, "Window System" },
+    { GL_DEBUG_SOURCE_SHADER_COMPILER, "Shader Compiler" },
+    { GL_DEBUG_SOURCE_THIRD_PARTY, "Third Party" },
+    { GL_DEBUG_SOURCE_APPLICATION, "Application" },
+    { GL_DEBUG_SOURCE_OTHER, "Other" },
+};
+
+static std::map<GLenum, char const *> gl_dbg_type_to_str
+{
+    { GL_DEBUG_TYPE_ERROR, "Error" },
+    { GL_DEBUG_TYPE_DEPRECATED_BEHAVIOR, "Deprecated Behaviour" },
+    { GL_DEBUG_TYPE_UNDEFINED_BEHAVIOR, "Undefined Behaviour" },
+    { GL_DEBUG_TYPE_PORTABILITY, "Portability" },
+    { GL_DEBUG_TYPE_PERFORMANCE, "Performance" },
+    { GL_DEBUG_TYPE_MARKER, "Marker" },
+    { GL_DEBUG_TYPE_PUSH_GROUP, "Push Group" },
+    { GL_DEBUG_TYPE_POP_GROUP, "Pop Group" },
+    { GL_DEBUG_TYPE_OTHER, "Other" },
+};
+
+static std::map<GLenum, char const *> gl_dbg_severity_to_str
+{
+    { GL_DEBUG_SEVERITY_HIGH, "High" },
+    { GL_DEBUG_SEVERITY_MEDIUM, "Medium" },
+    { GL_DEBUG_SEVERITY_LOW, "Low" },
+    { GL_DEBUG_SEVERITY_NOTIFICATION, "Notification" },
+};
+
+static void gl_debug(GLenum source, GLenum type, GLuint id,
+                     GLenum severity, GLsizei length,
+                     const GLchar *message, const void *user_param)
+{
+    switch (id)
+    {
+    default:
+        msg::debug("GL debug: %s\n", message);
+        if (gl_dbg_source_to_str.count(source) == 1)
+            msg::debug("  source: %s\n", gl_dbg_source_to_str[source]);
+        if (gl_dbg_type_to_str.count(type) == 1)
+            msg::debug("  type: %s\n", gl_dbg_type_to_str[type]);
+        msg::debug("  ID: %d\n", id);
+        if (gl_dbg_severity_to_str.count(severity) == 1)
+            msg::debug("  severity: %s\n", gl_dbg_severity_to_str[severity]);
+        break;
+    // Some debug messages are just annoying informational messages
+    case 131185: // glBufferData
+    case 131169: // glFramebufferRenderbuffer
+        break;
+    }
+}
+
+static void gl_debug_amd(GLuint id, GLenum category, GLenum severity,
+                         GLsizei length, const GLchar* message,
+                         GLvoid* user_param)
+{
+    gl_debug(GL_DEBUG_SOURCE_API, GL_DEBUG_TYPE_ERROR, id,
+             severity, length, message, user_param);
+}
+
+void gpu::setup_debug()
+{
+#if LOL_BUILD_DEBUG
+    GLint glflags;
+    glGetIntegerv(GL_CONTEXT_FLAGS, &glflags);
+
+    if (glflags & GL_CONTEXT_FLAG_DEBUG_BIT)
+    {
+        // Debug Output available
+
+        glEnable(GL_DEBUG_OUTPUT);
+        glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);
+#if defined LOL_USE_GLEW && !defined __APPLE__
+        if (GLEW_ARB_debug_output)
+            glDebugMessageCallbackARB(gl_debug, NULL);
+        else if (GLEW_AMD_debug_output)
+            glDebugMessageCallbackAMD(gl_debug_amd, NULL);
+        else if (GLEW_KHR_debug)
+#endif
+            glDebugMessageCallback(gl_debug, NULL);
+
+        glDebugMessageControl(GL_DONT_CARE, GL_DONT_CARE, GL_DONT_CARE, 0, NULL, GL_TRUE);
+    }
+#endif
+}
+
 void gpu::error(char const *msg, int error)
 {
     msg::error("%s: GL error 0x%04x\n", msg, error);

src/gpu/renderer.cpp

@@ -62,7 +62,8 @@ Renderer::Renderer(ivec2 size)
   : m_data(new RendererData())
 {
 #if defined LOL_USE_GLEW && !defined __APPLE__
-    /* Initialise GLEW if necessary */
+    // Initialise GLEW if necessary
+    // FIXME: move this somewhere else
     GLenum glerr = glewInit();
     if (glerr != GLEW_OK)
     {
@@ -71,6 +72,8 @@ Renderer::Renderer(ivec2 size)
     }
 #endif
 
+    gpu::setup_debug();
+
     /* Initialise rendering states */
     m_data->m_viewport = ibox2(0, 0, 0, 0);
     SetViewport(ibox2(ivec2::zero, size));
@@ -109,7 +112,7 @@ Renderer::Renderer(ivec2 size)
     SetPolygonMode(PolygonMode::Fill);
 
     /* Add some rendering states that we don't export to the user */
-#if defined HAVE_GL_2X && !defined __APPLE__
+#if defined HAVE_GL_2X && !defined GL_VERSION_3_1
     glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
 #endif
 }
@@ -218,6 +221,8 @@ void Renderer::SetAlphaFunc(AlphaFunc func, float alpha)
 
 #if defined HAVE_GLES_2X
     /* not supported */
+#elif defined GL_VERSION_3_1
+    /* deprecated */
 #elif defined GL_VERSION_1_1
     switch (func)
     {

src/lol/gpu/debug.h

@@ -18,6 +18,7 @@ namespace lol
 namespace gpu
 {
 
+void setup_debug();
 void error(char const *msg, int error);
 
 } // namespace gpu