Native bindings to the NV_alpha_to_coverage_dither_control extension.

NV_alpha_to_coverage_dither_control provides a new mechanism to control whether dithering is applied when the existing alpha to coverage functionality is used.

Modifier and Type Field Description

static int GL_ALPHA_TO_COVERAGE_DITHER_DEFAULT_NV Accepted by the param 

GL_ALPHA_TO_COVERAGE_DITHER_DISABLE_NV parameter of 

GL_ALPHA_TO_COVERAGE_DITHER_ENABLE_NV   AlphaToCoverageDitherControlNV.

static int GL_ALPHA_TO_COVERAGE_DITHER_MODE_NV

Accepted by the param of GetIntegerv.

Modifier and Type Method Description

static void glAlphaToCoverageDitherControlNV(int mode)

Version

    Last Modified Date:         May 31, 2017

    Revision:                   1.01

Modify the paragraph describing SAMPLE_ALPHA_TO_COVERAGE with

        ... No specific algorithm is required for converting the sample alpha values to a temporary coverage value. 

    It is intended that the number of 1's in the temporary coverage be proportional to the set of alpha values for the fragment, with all 1's  corresponding to 

    the maximum of all alpha values, and all 0's corresponding to all alpha values being 0. 

    The alpha values used to generate a coverage value are clamped to the range [0; 1]. 

    It is also intended that the algorithm be pseudo-random in nature, to avoid image artifacts due to regular coverage sample locations. 

    The function AlphaToCoverageDitherControlNV() allows to specify the kind of algorithm: 

If the mode is ALPHA_TO_COVERAGE_DITHER_ENABLE, the algorithm is different at different pixel locations. The dithering should be defined relative to window, not screen, coordinates, so that rendering results are invariant with respect to window position.

If the mode is ALPHA_TO_COVERAGE_DITHER_DISABLE, then no dithering should be applied and the same conversion should happen regardless of the pixel coordinates. 

If the mode is ALPHA_TO_COVERAGE_DITHER_DEFAULT, then the algorithm is implementation dependent.