read-framebuffer-to ( framebuffer-rect: framebuffer-rect gpu-data-ptr -- )
GPU-accelerated rendering » Framebuffer objects

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Vocabulary
gpu.framebuffers

Inputs

framebuffer-rect	a framebuffer-rect
gpu-data-ptr	a gpu-data-ptr

Outputs
None

Word description
Reads the rectangular region framebuffer-rect into gpu-data-ptr, which can reference either CPU memory (a byte-array or alien) or a GPU buffer-ptr. The format of the written data is determined by the component-order and component-type of the associated framebuffer-attachment.

Notes
User-created framebuffer objects require OpenGL 3.0 or one of the GL_ARB_framebuffer_object or GL_EXT_framebuffer_object extensions. Reading into a buffer-ptr requires OpenGL 2.1 or the GL_ARB_pixel_buffer_object extension.

See also
read-framebuffer, read-framebuffer-image

Definition

USING: accessors gpu.buffers gpu.framebuffers.private kernel
opengl.gl opengl.textures sequences typed ;

IN: gpu.framebuffers

TYPED:: read-framebuffer-to
    ( framebuffer-rect: framebuffer-rect gpu-data-ptr -- )
    GL_READ_FRAMEBUFFER framebuffer-rect framebuffer>>
    framebuffer-handle glBindFramebuffer framebuffer-rect
    [ framebuffer>> ] [ attachment>> ] bi gl-attachment
    glReadBuffer framebuffer-rect rect>>
    [ loc>> first2 ] [ dim>> first2 ] bi
    framebuffer-rect framebuffer-rect-image-type
    image-data-format gpu-data-ptr pixel-pack-buffer
    [ glReadPixels ] with-gpu-data-ptr ;