- trying to fix bug 2781865

[freeglut] / progs / demos / smooth_opengl3 / smooth_opengl3.c

diff --git a/progs/demos/smooth_opengl3/smooth_opengl3.c b/progs/demos/smooth_opengl3/smooth_opengl3.c
index e30e9f4..622b95c 100755 (executable)
--- a/progs/demos/smooth_opengl3/smooth_opengl3.c
+++ b/progs/demos/smooth_opengl3/smooth_opengl3.c
@@ -52,9 +52,8 @@
 void checkError(const char *functionName)
 {
    GLenum error;
-   while (( error = glGetError() ) != GL_NO_ERROR) {\r
-      const GLubyte* sError = gluErrorString(error);
-      fprintf (stderr, "GL error 0x%X, %s, detected in %s\n", error, sError, functionName);
+   while (( error = glGetError() ) != GL_NO_ERROR) {
+      fprintf (stderr, "GL error 0x%X detected in %s\n", error, functionName);
    }
 }
 
@@ -99,9 +98,17 @@ typedef char ourGLchar;
 #define APIENTRY
 #endif
 
+
+#ifndef GL_ARB_vertex_array_object
+typedef void (APIENTRY *PFNGLGENVERTEXARRAYSPROC) (GLsizei n, GLuint *arrays);
+typedef void (APIENTRY *PFNGLBINDVERTEXARRAYPROC) (GLuint array);
+#endif
+#ifndef GL_VERSION_1_5
 typedef void (APIENTRY *PFNGLGENBUFFERSPROC) (GLsizei n, GLuint *buffers);
 typedef void (APIENTRY *PFNGLBINDBUFFERPROC) (GLenum target, GLuint buffer);
 typedef void (APIENTRY *PFNGLBUFFERDATAPROC) (GLenum target, ourGLsizeiptr size, const GLvoid *data, GLenum usage);
+#endif
+#ifndef GL_VERSION_2_0
 typedef GLuint (APIENTRY *PFNGLCREATESHADERPROC) (GLenum type);
 typedef void (APIENTRY *PFNGLSHADERSOURCEPROC) (GLuint shader, GLsizei count, const ourGLchar **string, const GLint *length);
 typedef void (APIENTRY *PFNGLCOMPILESHADERPROC) (GLuint shader);
@@ -118,7 +125,10 @@ typedef void (APIENTRY *PFNGLVERTEXATTRIBPOINTERPROC) (GLuint index, GLint size,
 typedef void (APIENTRY *PFNGLENABLEVERTEXATTRIBARRAYPROC) (GLuint index);
 typedef GLint (APIENTRY *PFNGLGETUNIFORMLOCATIONPROC) (GLuint program, const ourGLchar *name);
 typedef void (APIENTRY *PFNGLUNIFORMMATRIX4FVPROC) (GLint location, GLsizei count, GLboolean transpose, const GLfloat *value);
+#endif
 
+PFNGLGENVERTEXARRAYSPROC gl_GenVertexArrays;
+PFNGLBINDVERTEXARRAYPROC gl_BindVertexArray;
 PFNGLGENBUFFERSPROC gl_GenBuffers;
 PFNGLBINDBUFFERPROC gl_BindBuffer;
 PFNGLBUFFERDATAPROC gl_BufferData;
@@ -139,8 +149,10 @@ PFNGLENABLEVERTEXATTRIBARRAYPROC gl_EnableVertexAttribArray;
 PFNGLGETUNIFORMLOCATIONPROC gl_GetUniformLocation;
 PFNGLUNIFORMMATRIX4FVPROC gl_UniformMatrix4fv;
 
-void initExtensionEntries(void) 
+void initExtensionEntries(void)
 {
+   gl_GenVertexArrays = (PFNGLGENVERTEXARRAYSPROC) glutGetProcAddress ("glGenVertexArrays");
+   gl_BindVertexArray = (PFNGLBINDVERTEXARRAYPROC) glutGetProcAddress ("glBindVertexArray");
    gl_GenBuffers = (PFNGLGENBUFFERSPROC) glutGetProcAddress ("glGenBuffers");
    gl_BindBuffer = (PFNGLBINDBUFFERPROC) glutGetProcAddress ("glBindBuffer");
    gl_BufferData = (PFNGLBUFFERDATAPROC) glutGetProcAddress ("glBufferData");
@@ -185,9 +197,17 @@ enum {
 
 /* the name of the vertex buffer object */
 GLuint vertexBufferName;
+GLuint vertexArrayName;
 
 void initBuffer(void)
 {
+   /* Need to setup a vertex array as otherwise invalid operation errors can
+    * occur when accessing vertex buffer (OpenGL 3.3 has no default zero named
+    * vertex array) 
+    */
+   gl_GenVertexArrays(1, &vertexArrayName);
+   gl_BindVertexArray(vertexArrayName);
+
    gl_GenBuffers (1, &vertexBufferName);
    gl_BindBuffer (GL_ARRAY_BUFFER, vertexBufferName);
    gl_BufferData (GL_ARRAY_BUFFER, sizeof(varray), varray, GL_STATIC_DRAW);