Support MRT in QOpenGLFramebufferObject

Introduce overloads in the API to allow specifying multiple color
attachment sizes and formats. When these are in use and MRT is supported,
a texture or renderbuffer is created for each of GL_COLOR_ATTACHMENT0, 1, 2, ...

[ChangeLog] Added support for multiple render targets in QOpenGLFramebufferObject

Task-number: QTBUG-39235
Change-Id: Ie7cfd81d1b796a9166b80dff7513aafe0120d53d
Reviewed-by: Jørgen Lind <jorgen.lind@theqtcompany.com>

1 files changed, 19 insertions, 3 deletions

diff --git a/src/gui/opengl/qopenglframebufferobject.h b/src/gui/opengl/qopenglframebufferobject.h
index 4ce0ee26cb..cead4ad10f 100644
--- a/src/gui/opengl/qopenglframebufferobject.h
+++ b/src/gui/opengl/qopenglframebufferobject.h
@@ -63,15 +63,18 @@ public:
     QOpenGLFramebufferObject(int width, int height, GLenum target = GL_TEXTURE_2D);
 
     QOpenGLFramebufferObject(const QSize &size, Attachment attachment,
-                         GLenum target = GL_TEXTURE_2D, GLenum internal_format = 0);
+                         GLenum target = GL_TEXTURE_2D, GLenum internalFormat = 0);
     QOpenGLFramebufferObject(int width, int height, Attachment attachment,
-                         GLenum target = GL_TEXTURE_2D, GLenum internal_format = 0);
+                         GLenum target = GL_TEXTURE_2D, GLenum internalFormat = 0);
 
     QOpenGLFramebufferObject(const QSize &size, const QOpenGLFramebufferObjectFormat &format);
     QOpenGLFramebufferObject(int width, int height, const QOpenGLFramebufferObjectFormat &format);
 
     virtual ~QOpenGLFramebufferObject();
 
+    void addColorAttachment(const QSize &size, GLenum internalFormat = 0);
+    void addColorAttachment(int width, int height, GLenum internalFormat = 0);
+
     QOpenGLFramebufferObjectFormat format() const;
 
     bool isValid() const;
@@ -83,12 +86,19 @@ public:
     int height() const { return size().height(); }
 
     GLuint texture() const;
+    QVector<GLuint> textures() const;
+
     GLuint takeTexture();
+    GLuint takeTexture(int colorAttachmentIndex);
+
     QSize size() const;
+    QVector<QSize> sizes() const;
+
     QImage toImage() const;
     QImage toImage(bool flipped) const;
-    Attachment attachment() const;
+    QImage toImage(bool flipped, int colorAttachmentIndex) const;
 
+    Attachment attachment() const;
     void setAttachment(Attachment attachment);
 
     GLuint handle() const;
@@ -100,6 +110,12 @@ public:
     static bool hasOpenGLFramebufferBlit();
     static void blitFramebuffer(QOpenGLFramebufferObject *target, const QRect &targetRect,
                                 QOpenGLFramebufferObject *source, const QRect &sourceRect,
+                                GLbitfield buffers,
+                                GLenum filter,
+                                int readColorAttachmentIndex,
+                                int drawColorAttachmentIndex);
+    static void blitFramebuffer(QOpenGLFramebufferObject *target, const QRect &targetRect,
+                                QOpenGLFramebufferObject *source, const QRect &sourceRect,
                                 GLbitfield buffers = GL_COLOR_BUFFER_BIT,
                                 GLenum filter = GL_NEAREST);
     static void blitFramebuffer(QOpenGLFramebufferObject *target,