1 files changed, 89 insertions, 41 deletions

diff --git a/tests/OffscreenContextWGL.cc b/tests/OffscreenContextWGL.cc
index 863da31..17c49c6 100644
--- a/tests/OffscreenContextWGL.cc
+++ b/tests/OffscreenContextWGL.cc
@@ -2,6 +2,13 @@
 
 Create an OpenGL context without creating an OpenGL Window. for Windows.
 
+For more info:
+
+   http://www.nullterminator.net/opengl32.html by Blaine Hodge 
+   http://msdn.microsoft.com/en-us/library/ee418815(v=vs.85).aspx
+   http://www.cprogramming.com/tutorial/wgl_wiggle_functions.html by RoD
+    ( which includes robot.cc by Steven Billington )
+   http://blogs.msdn.com/b/oldnewthing/archive/2006/12/04/1205831.aspx by Tom
 */
 
 #include <windows.h>
@@ -35,13 +42,12 @@ void offscreen_context_init(OffscreenContext &ctx, int width, int height)
   ctx.fbo = NULL;
 }
 
-
 void glewCheck() {
 #ifdef DEBUG
   cerr << "GLEW version " << glewGetString(GLEW_VERSION) << "\n";
   cerr << (const char *)glGetString(GL_RENDERER) << "(" << (const char *)glGetString(GL_VENDOR) << ")\n"
        << "OpenGL version " << (const char *)glGetString(GL_VERSION) << "\n";
-  cerr  << "Extensions: " << (const char *)glGetString(GL_EXTENSIONS) << "\n";
+  //cerr  << "Extensions: " << (const char *)glGetString(GL_EXTENSIONS) << "\n";
 
   if (GLEW_ARB_framebuffer_object) {
     cerr << "ARB_FBO supported\n";
@@ -57,46 +63,81 @@ void glewCheck() {
 
 LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) 
 {
-	return DefWindowProc( hwnd, message, wparam, lparam );
+  return DefWindowProc( hwnd, message, wparam, lparam );
 }
 
 bool create_wgl_dummy_context(OffscreenContext &ctx)
 {
-	// create window
-
-        HINSTANCE inst = GetModuleHandle(0);
-	WNDCLASS wc;
-        ZeroMemory( &wc, sizeof( wc ) );
-	wc.style = CS_OWNDC;
-	wc.lpfnWndProc = WndProc;
-	wc.hInstance = inst;
-	wc.lpszClassName = "OpenSCAD";
-	RegisterClass( &wc );
-	
-	HWND window = CreateWindow( "OpenSCAD", "OpenSCAD", 
-		WS_CAPTION | WS_POPUPWINDOW | WS_VISIBLE,
-		0, 0, 256, 256,	NULL, NULL, inst, NULL );
-	
+  // this call alters ctx->window and ctx->openGLContext 
+  //  and ctx->dev_context if successfull
+  // create window
+
+  HINSTANCE inst = GetModuleHandle(0);
+  WNDCLASS wc;
+  ZeroMemory( &wc, sizeof( wc ) );
+  wc.style = CS_OWNDC;
+  wc.lpfnWndProc = WndProc;
+  wc.hInstance = inst;
+  wc.lpszClassName = "OpenSCAD";
+  RegisterClass( &wc );
 	
-	// create WGL context, make current
-
-	PIXELFORMATDESCRIPTOR pixformat;
-	int chosenformat;
-	HDC dev_context = GetDC( window );
-	ZeroMemory( &pixformat, sizeof( pixformat ) );
-	pixformat.nSize = sizeof( pixformat );
-	pixformat.nVersion = 1;
-	pixformat.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL;
-	pixformat.iPixelType = PFD_TYPE_RGBA;
-	pixformat.cColorBits = 24;
-	pixformat.cDepthBits = 16;
-	pixformat.iLayerType = PFD_MAIN_PLANE;
-	chosenformat = ChoosePixelFormat( dev_context, &pixformat );
-	SetPixelFormat( dev_context, chosenformat, &pixformat );
-	HGLRC gl_render_context = wglCreateContext( dev_context );
-	wglMakeCurrent( dev_context, gl_render_context );
-
-	return true;
+  HWND window = CreateWindow( "OpenSCAD", "OpenSCAD", 
+    WS_CAPTION | WS_POPUPWINDOW,  //| WS_VISIBLE,
+    0, 0, ctx.width, ctx.height, NULL, NULL, inst, NULL );
+
+  if ( window==NULL ) {
+    cerr << "MS GDI - CreateWindow failed\n";
+    return false;
+  }
+
+  // create WGL context, make current
+
+  PIXELFORMATDESCRIPTOR pixformat;
+  int chosenformat;
+  HDC dev_context = GetDC( window );
+  if ( dev_context == NULL ) {
+      cerr << "MS GDI - GetDC failed\n";
+      return false;
+  }
+
+  ZeroMemory( &pixformat, sizeof( pixformat ) );
+  pixformat.nSize = sizeof( pixformat );
+  pixformat.nVersion = 1;
+  pixformat.dwFlags = PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL;
+  pixformat.iPixelType = PFD_TYPE_RGBA;
+  pixformat.cColorBits = 24;
+  pixformat.cDepthBits = 16;
+  pixformat.iLayerType = PFD_MAIN_PLANE;
+  chosenformat = ChoosePixelFormat( dev_context, &pixformat );
+  if (chosenformat==0) {
+    cerr << "MS GDI - ChoosePixelFormat failed\n";
+    return false;
+  }
+
+  bool spfok = SetPixelFormat( dev_context, chosenformat, &pixformat );
+  if (!spfok) {
+    cerr << "MS GDI - SetPixelFormat failed\n";
+    return false;
+  }
+
+  HGLRC gl_render_context = wglCreateContext( dev_context );
+  if ( gl_render_context == NULL ) {
+      cerr << "MS WGL - wglCreateContext failed\n";
+      ReleaseDC( ctx.window, ctx.dev_context );
+      return false;
+  }
+
+  bool mcok = wglMakeCurrent( dev_context, gl_render_context );
+  if (!mcok) {
+    cerr << "MS GDI - wglMakeCurrent failed\n";
+    return false;
+  }
+
+  ctx.window = window;
+  ctx.dev_context = dev_context;
+  ctx.openGLContext = gl_render_context;
+
+  return true;
 }
 
 
@@ -105,22 +146,29 @@ OffscreenContext *create_offscreen_context(int w, int h)
   OffscreenContext *ctx = new OffscreenContext;
   offscreen_context_init( *ctx, w, h );
 
-  // before an FBO can be setup, a WGL context must be created
-  // this call alters ctx->window and ctx->openGLContext 
+  // Before an FBO can be setup, a WGL context must be created. 
+  // This call alters ctx->window and ctx->openGLContext 
   //  and ctx->dev_context if successfull
   if (!create_wgl_dummy_context( *ctx )) {
+    cerr << "wgl dummy fail\n";
+    fflush(stderr);
     return NULL;
   }
 
-  glewInit(); //must come after Context creation and before FBO calls.
+  GLenum err = glewInit(); // must come after Context creation and before FBO calls.
+  if (GLEW_OK != err) {
+    cerr << "Unable to init GLEW: " << glewGetErrorString(err) << "\n";
+    fflush(stderr);
+    return NULL;
+  }
   glewCheck();
 
   ctx->fbo = fbo_new();
   if (!fbo_init(ctx->fbo, w, h)) {
+    cerr << "fbo didn't init\n";
     return NULL;
   }
 
-  ctx = NULL;
   return ctx;
 }