Name INGR_interlace_read Name Strings GL_INGR_interlace_read Version Date: 12/14/98 Revision: 1.0 Number 175 Dependencies None Overview This extension provides a way to skip rows of pixels when reading or copying pixel rectangles. This extension is complementary to the EXT_interlace extension except that it has no affect on getting texture images. New Procedures and Functions None New Tokens Accepted by the parameter of of Enable, Disable, IsEnabled, and by the parameter of GetBooleanv, GetIntegerv, GetFloatv, GetDoublev: INTERLACE_READ_INGR 0x8568 Additions to Chapter 2 of the 1.2 Specification (OpenGL Operation) None Additions to Chapter 3 of the 1.2 Specification (Rasterization) None Additions to Chapter 4 of the 1.2 Specification (Per-Fragment Operations and the Frame Buffer) [In section 4.3.2 "Reading Pixels" the specification of an interlace read operation is added to the GL Specification in the sectino on "Obtaining Pixels from the FrameBuffer."] Reading interlaced rows of pixels is enabled or disabled with Enable or Disable using the symbolic constant INTERLACE_READ_INGR. If INTERLACE_READ_INGR is disabled, then ReadPixels obtains values from the selected buffer from each pixel with lower left hand corner at (x+i, y+j) for 0 <= i < width and 0 <= j < height; this pixel is said to be the ith pixel in the jth row. If INTERLACE_READ_INGR is enabled, then ReadPixels obtains values from the selected buffer from each pixel with lower left hand corner at (x+i, y+(j*2)) for 0 <= i < width and 0 <= j < height; this pixel is said to be the ith pixel in the jth row. If any of these pixels lies outside of the window... Additions to Chapter 5 of the 1.2 Specification (Special Functions) None Additions to Chapter 6 of the 1.2 Specification (State and State Requests) None Additions to the GLX Specification None Errors None New State Get Value Get Command Type Initial Value Attribute -------------------- --------------- ----- -------------- ------------- INTERLACE_READ_INGR IsEnabled B False pixel/enable New Implementation Dependent State None