start fbo

kivy/c_ext/graphics/.gitignore

@@ -0,0 +1 @@
+*.c

kivy/c_ext/graphics/fbo.pxd

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+from c_opengl cimport *
+from instructions cimport RenderContext, Canvas
+
+class Fbo(RenderContext):
+    cdef int width
+    cdef int height
+    cdef int depthbuffer_attached
+    cdef list clear_color
+    cdef GLuint buffer_id
+    cdef GLuint depthbuffer_id
+    cdef object texture
+
+    cdef bind(self)
+    cdef release(self)
+    cdef clear(self)
+
+

kivy/c_ext/graphics/fbo.pyx

@@ -0,0 +1,87 @@
+__all__ = ('Fbo',)
+
+
+import kivy
+from kivy import Logger
+
+from c_opengl cimport *
+from instructions cimport RenderContext, Canvas
+
+cdef class Fbo(RenderContext):
+    def __init__(self, *args, **kwargs):
+        RenderContext.__init__(self, *args, **kwargs)
+
+        kwargs.setdefault('clear_color', (0, 0, 0, 0))
+        kwargs.setdefault('size', (1024, 1024))
+        kwargs.setdefault('push_viewport', False)
+        kwargs.setdefault('with_depthbuffer', True)
+
+        self.size                 = kwargs.get('size')
+        self.clear_color          = kwargs.get('clear_color')
+        self.depthbuffer_attached = kwargs.get('with_depthbuffer')
+        self.push_viewport        = kwargs.get('push_viewport')
+        self._is_bound             = False
+
+        # create buffers and textures
+        self.texture = kivy.Texture.create(self.width, self.height)
+
+        cdef GLuint id
+        glGenFramebuffers(1, &id)
+        self.buffer_id = id
+        glBindFramebuffer(GL_FRAMEBUFFER, self.buffer_id)
+        
+        if self.depthbuffer_attached:
+            glGenRenderbuffers(1, &id)
+            self.depthbuffer_id = id
+            glBindRenderbuffer(GL_RENDERBUFFER, self.depthbuffer_id)
+            glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, 
+                                  self.width, self.height)
+            glBindRenderbuffer(GL_RENDERBUFFER, 0)
+            glFramebufferRenderbuffer(GL_FRAMEBUFFER, 
+                                         GL_DEPTH_ATTACHMENT,
+                                         GL_RENDERBUFFER, 
+                                         self.depthbuffer_id)
+
+        glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
+                GL_TEXTURE_2D, self.texture.id, 0)
+
+        cdef int status = glCheckFramebufferStatus(GL_FRAMEBUFFER)
+        if status:
+            Logger.error("Error initializing FBO.  %d" % status)
+
+
+        glBindFramebuffer(GL_FRAMEBUFFER, 0)
+
+
+    def bind(self):
+        self._is_bound = True
+        glBindFramebuffer(GL_FRAMEBUFFER, self.framebuffer)
+        glViewport(0, 0, self.width, self.height)
+
+    def release(self):
+        self._is_bound = False
+        glBindFramebuffer(GL_FRAMEBUFFER, 0)
+        
+    def clear(self):
+        cdef float c[4] 
+        c[0] = self.clear_color[0]
+        c[1] = self.clear_color[2]
+        c[2] = self.clear_color[2]
+        c[3] = self.clear_color[3]
+        glClearColor(c[0],c[1],c[2],c[3])
+        if self.depthbuffer_attached:
+            glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
+        else:
+            glClear(GL_COLOR_BUFFER_BIT)
+
+
+    def __enter__(self):
+        Canvas.__enter__(self)
+        self.bind()
+
+    def __exit__(self, type, value, traceback):
+        Canvas.__exit__(self, type, value, traceback)
+        self.release()
+ 
+
+