OpenGL: Add a set of version and context specific OpenGL classes

This commit adds part of the output of utils/glgen and some simple
modifications to QOpenGLContext to allow easy access to classes
containing functions specific to a given OpenGL context and version.

This allows compile-time detection of mis-use of OpenGL features.
For example, trying to use glBegin(GL_TRIANGLES) with an OpenGL 3.2
Core Profile context will be detected by the compiler rather than at
runtime.

These capabilities make it much easier to add functionality to Qt and
applications that relies upon core features of OpenGL from specific
versions e.g. geometry shaders.

Change-Id: Ieb584a489792595f831bc77dee84935c03bb5a64
Reviewed-by: Samuel Rødal <samuel.rodal@digia.com>

1 files changed, 129 insertions, 0 deletions

diff --git a/src/gui/opengl/qopengl.h b/src/gui/opengl/qopengl.h
index e1d36662d1..049bb23207 100644
--- a/src/gui/opengl/qopengl.h
+++ b/src/gui/opengl/qopengl.h
@@ -108,6 +108,135 @@ typedef GLfloat GLdouble;
 
 QT_BEGIN_NAMESPACE
 
+
+// When all else fails we provide sensible fallbacks - this is needed to
+// allow compilation on OS X 10.6
+#if !defined(QT_OPENGL_ES_2)
+
+// OS X 10.6 doesn't define these which are needed below
+// OS X 10.7 and later defien them in gl3.h
+#ifndef APIENTRY
+#define APIENTRY
+#endif
+#ifndef APIENTRYP
+#define APIENTRYP APIENTRY *
+#endif
+#ifndef GLAPI
+#define GLAPI extern
+#endif
+
+
+// This block is copied from glext.h and defines the types needed by
+// a few extension classes.
+
+#include <stddef.h>
+#ifndef GL_VERSION_2_0
+/* GL type for program/shader text */
+typedef char GLchar;
+#endif
+
+#ifndef GL_VERSION_1_5
+/* GL types for handling large vertex buffer objects */
+typedef ptrdiff_t GLintptr;
+typedef ptrdiff_t GLsizeiptr;
+#endif
+
+#ifndef GL_ARB_vertex_buffer_object
+/* GL types for handling large vertex buffer objects */
+typedef ptrdiff_t GLintptrARB;
+typedef ptrdiff_t GLsizeiptrARB;
+#endif
+
+#ifndef GL_ARB_shader_objects
+/* GL types for program/shader text and shader object handles */
+typedef char GLcharARB;
+typedef unsigned int GLhandleARB;
+#endif
+
+/* GL type for "half" precision (s10e5) float data in host memory */
+#ifndef GL_ARB_half_float_pixel
+typedef unsigned short GLhalfARB;
+#endif
+
+#ifndef GL_NV_half_float
+typedef unsigned short GLhalfNV;
+#endif
+
+#ifndef GLEXT_64_TYPES_DEFINED
+/* This code block is duplicated in glxext.h, so must be protected */
+#define GLEXT_64_TYPES_DEFINED
+/* Define int32_t, int64_t, and uint64_t types for UST/MSC */
+/* (as used in the GL_EXT_timer_query extension). */
+#if defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L
+#include <inttypes.h>
+#elif defined(__sun__) || defined(__digital__)
+#include <inttypes.h>
+#if defined(__STDC__)
+#if defined(__arch64__) || defined(_LP64)
+typedef long int int64_t;
+typedef unsigned long int uint64_t;
+#else
+typedef long long int int64_t;
+typedef unsigned long long int uint64_t;
+#endif /* __arch64__ */
+#endif /* __STDC__ */
+#elif defined( __VMS ) || defined(__sgi)
+#include <inttypes.h>
+#elif defined(__SCO__) || defined(__USLC__)
+#include <stdint.h>
+#elif defined(__UNIXOS2__) || defined(__SOL64__)
+typedef long int int32_t;
+typedef long long int int64_t;
+typedef unsigned long long int uint64_t;
+#elif defined(_WIN32) && defined(__GNUC__)
+#include <stdint.h>
+#elif defined(_WIN32)
+typedef __int32 int32_t;
+typedef __int64 int64_t;
+typedef unsigned __int64 uint64_t;
+#else
+/* Fallback if nothing above works */
+#include <inttypes.h>
+#endif
+#endif
+
+#ifndef GL_EXT_timer_query
+typedef int64_t GLint64EXT;
+typedef uint64_t GLuint64EXT;
+#endif
+
+#ifndef GL_ARB_sync
+typedef int64_t GLint64;
+typedef uint64_t GLuint64;
+typedef struct __GLsync *GLsync;
+#endif
+
+#ifndef GL_ARB_cl_event
+/* These incomplete types let us declare types compatible with OpenCL's cl_context and cl_event */
+struct _cl_context;
+struct _cl_event;
+#endif
+
+#ifndef GL_ARB_debug_output
+typedef void (APIENTRY *GLDEBUGPROCARB)(GLenum source,GLenum type,GLuint id,GLenum severity,GLsizei length,const GLchar *message,GLvoid *userParam);
+#endif
+
+#ifndef GL_AMD_debug_output
+typedef void (APIENTRY *GLDEBUGPROCAMD)(GLuint id,GLenum category,GLenum severity,GLsizei length,const GLchar *message,GLvoid *userParam);
+#endif
+
+#ifndef GL_KHR_debug
+typedef void (APIENTRY *GLDEBUGPROC)(GLenum source,GLenum type,GLuint id,GLenum severity,GLsizei length,const GLchar *message,GLvoid *userParam);
+#endif
+
+#ifndef GL_NV_vdpau_interop
+typedef GLintptr GLvdpauSurfaceNV;
+#endif
+
+// End of block copied from glext.h
+#endif
+
+
 // Types that aren't defined in all system's gl.h files.
 typedef ptrdiff_t qopengl_GLintptr;
 typedef ptrdiff_t qopengl_GLsizeiptr;