@@ -1,4 +1,5 @@

 /// Inlcudes

+#include <iostream>

 #include "MicroGlut.h"

 #include "GL_utilities.h"

@@ -17,17 +18,37 @@ GLfloat positions[][3] =

 };

+/// Debug message callback

+void APIENTRY debugMessageCallback(

+    GLenum          /* source    */,

+    GLenum          /* type      */,

+    GLuint          /* id        */,

+    GLenum          /* severity  */,

+    GLsizei         /* length    */,

+    GLchar  const *    message,

+    void    const * /* userParam */

+)

+{

+    std::cerr << message << std::endl;

+}

+

+

 /// Init

 void init(void)

 {

+    // Debug message callback.

+    // Requires OpenGL 4.3 or the GL_KHR_debug extension (which is not hardware

+    // dependent and supported almost everywhere *except* MacOS).

+    glEnable(GL_DEBUG_OUTPUT);

+    glEnable(GL_DEBUG_OUTPUT_SYNCHRONOUS);

+    glDebugMessageCallback(debugMessageCallback, nullptr);

+

     // GL inits.

     glClearColor(0.2, 0.2, 0.5, 0.0);

     glDisable(GL_DEPTH_TEST);

-    printError("init GL");

     // Load and compile shader.

     GLuint program = loadShaders("tsbk07.vert", "tsbk07.frag");

-    printError("init shader");

     // Allocate and activate Vertex Array Object (VAO), used for uploading

     // the geometry.

@@ -42,7 +63,6 @@ void init(void)

     glBufferData(GL_ARRAY_BUFFER, sizeof(positions), positions, GL_STATIC_DRAW);

     glVertexAttribPointer(positionLocation, 3, GL_FLOAT, GL_FALSE, 0, 0);

     glEnableVertexAttribArray(positionLocation);

-    printError("init VBOs");

 }

@@ -56,7 +76,6 @@ void display(void)

     glBindVertexArray(vertexArray);

     // Draw.

-    printError("display draw");

     glDrawArrays(GL_TRIANGLES, 0, ARRAY_COUNT(positions));

     // Show on the screen.