Add support for glMapBufferRange in the wrappers and resolvers

QOpenGLBuffer::map() and related helpers are becoming useless in
OpenGL ES 3.0 and up: instead of the old GL_OES_map_buffer,
glMapBufferRange, but not glMapBuffer, is now part of the standard.
On desktop GL_ARB_map_buffer_range is present by default in OpenGL 3.0
and newer.

[ChangeLog][QtGui] Added QOpenGLBuffer::mapBufferRange().

Task-number: QTBUG-38168
Change-Id: I4e9bbe8ced9ee4d535ac32849a8c08c26d79cb49
Reviewed-by: Gunnar Sletta <gunnar.sletta@jollamobile.com>

1 files changed, 15 insertions, 1 deletions

diff --git a/src/gui/opengl/qopenglextensions_p.h b/src/gui/opengl/qopenglextensions_p.h
index 065cbb0e57..907e315e41 100644
--- a/src/gui/opengl/qopenglextensions_p.h
+++ b/src/gui/opengl/qopenglextensions_p.h
@@ -99,7 +99,8 @@ public:
         Depth24                 = 0x00010000,
         SRGBFrameBuffer         = 0x00020000,
         MapBuffer               = 0x00040000,
-        GeometryShaders         = 0x00080000
+        GeometryShaders         = 0x00080000,
+        MapBufferRange          = 0x00100000
     };
     Q_DECLARE_FLAGS(OpenGLExtensions, OpenGLExtension)
 
@@ -107,6 +108,7 @@ public:
     bool hasOpenGLExtension(QOpenGLExtensions::OpenGLExtension extension) const;
 
     GLvoid *glMapBuffer(GLenum target, GLenum access);
+    GLvoid *glMapBufferRange(GLenum target, qopengl_GLintptr offset, qopengl_GLsizeiptr length, GLbitfield access);
     GLboolean glUnmapBuffer(GLenum target);
 
     void glBlitFramebuffer(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
@@ -131,6 +133,8 @@ public:
     explicit QOpenGLExtensionsPrivate(QOpenGLContext *ctx);
 
     GLvoid* (QOPENGLF_APIENTRYP MapBuffer)(GLenum target, GLenum access);
+    GLvoid* (QOPENGLF_APIENTRYP MapBufferRange)(GLenum target, qopengl_GLintptr offset,
+                                                qopengl_GLsizeiptr length, GLbitfield access);
     GLboolean (QOPENGLF_APIENTRYP UnmapBuffer)(GLenum target);
     void (QOPENGLF_APIENTRYP BlitFramebuffer)(GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
                            GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
@@ -150,6 +154,16 @@ inline GLvoid *QOpenGLExtensions::glMapBuffer(GLenum target, GLenum access)
     return result;
 }
 
+inline GLvoid *QOpenGLExtensions::glMapBufferRange(GLenum target, qopengl_GLintptr offset,
+                                                   qopengl_GLsizeiptr length, GLbitfield access)
+{
+    Q_D(QOpenGLExtensions);
+    Q_ASSERT(QOpenGLExtensions::isInitialized(d));
+    GLvoid *result = d->MapBufferRange(target, offset, length, access);
+    Q_OPENGL_FUNCTIONS_DEBUG
+    return result;
+}
+
 inline GLboolean QOpenGLExtensions::glUnmapBuffer(GLenum target)
 {
     Q_D(QOpenGLExtensions);