More refactoring of offscreen rendering

1 files changed, 8 insertions, 50 deletions

diff --git a/tests/OffscreenContext.mm b/tests/OffscreenContext.mm
index 8797e49..90af712 100644
--- a/tests/OffscreenContext.mm
+++ b/tests/OffscreenContext.mm
@@ -1,14 +1,9 @@
 #include "OffscreenContext.h"
 #include "imageutils.h"
+#include "fboutils.h"
 
-#import <OpenGL/OpenGL.h>
-#import <OpenGL/glu.h>      // for gluCheckExtension
 #import <AppKit/AppKit.h>   // for NSOpenGL...
 
-// Simple error reporting macros to help keep the sample code clean
-#define REPORT_ERROR_AND_EXIT(desc) { std::cout << desc << "\n"; return false; }
-#define NULL_ERROR_EXIT(test, desc) { if (!test) REPORT_ERROR_AND_EXIT(desc); }
-
 struct OffscreenContext
 {
   NSOpenGLContext *openGLContext;
@@ -41,58 +36,21 @@ OffscreenContext *create_offscreen_context(int w, int h)
 
   // Create and make current the OpenGL context to render with (with color and depth buffers)
   ctx->openGLContext = [[NSOpenGLContext alloc] initWithFormat:pixFormat shareContext:nil];
-  NULL_ERROR_EXIT(ctx->openGLContext, "Unable to create NSOpenGLContext");
-
-  [ctx->openGLContext makeCurrentContext];
-
-  // Test if framebuffer objects are supported
-  // FIXME: Use GLEW
-  const GLubyte* strExt = glGetString(GL_EXTENSIONS);
-  GLboolean fboSupported = gluCheckExtension((const GLubyte*)"GL_EXT_framebuffer_object", strExt);
-  if (!fboSupported)
-    REPORT_ERROR_AND_EXIT("Your system does not support framebuffer extension - unable to render scene");
-
-  // Create an FBO
-  GLuint renderBuffer = 0;
-  GLuint depthBuffer = 0;
-  // Depth buffer to use for depth testing - optional if you're not using depth testing
-  glGenRenderbuffersEXT(1, &depthBuffer);
-  glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, depthBuffer);
-  glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_DEPTH_COMPONENT24,  w, h);
-  REPORTGLERROR("creating depth render buffer");
-
-  // Render buffer to use for imaging
-  glGenRenderbuffersEXT(1, &renderBuffer);
-  glBindRenderbufferEXT(GL_RENDERBUFFER_EXT, renderBuffer);
-  glRenderbufferStorageEXT(GL_RENDERBUFFER_EXT, GL_RGBA8, w, h);
-  REPORTGLERROR("creating color render buffer");
-  ctx->fbo = 0;
-  glGenFramebuffersEXT(1, &ctx->fbo);
-  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, ctx->fbo);
-  REPORTGLERROR("binding framebuffer");
-
-  glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, 
-                               GL_RENDERBUFFER_EXT, renderBuffer);
-  REPORTGLERROR("specifying color render buffer");
-
-  if (glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT) !=  GL_FRAMEBUFFER_COMPLETE_EXT) {
-    REPORT_ERROR_AND_EXIT("Problem with OpenGL framebuffer after specifying color render buffer.");
+  if (!ctx->openGLContext) {
+    std::cerr << "Unable to create NSOpenGLContext\n";
+    return NULL;
   }
 
-  glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT, GL_RENDERBUFFER_EXT, depthBuffer);
-  REPORTGLERROR("specifying depth render buffer");
+  [ctx->openGLContext makeCurrentContext];
 
-  if (glCheckFramebufferStatusEXT(GL_FRAMEBUFFER_EXT) != GL_FRAMEBUFFER_COMPLETE_EXT) {
-    REPORT_ERROR_AND_EXIT("Problem with OpenGL framebuffer after specifying depth render buffer.");
-  }
+  ctx->fbo = fbo_create(w, h);
 
   return ctx;
 }
 
 bool teardown_offscreen_context(OffscreenContext *ctx)
 {
-  // "un"bind my FBO
-  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, 0);
+  fbo_unbind();
 
   /*
    * Cleanup
@@ -139,5 +97,5 @@ bool save_framebuffer(OffscreenContext *ctx, const char *filename)
 
 void bind_offscreen_context(OffscreenContext *ctx)
 {
-  glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, ctx->fbo);
+  fbo_bind(ctx->fbo);
 }