C Specification
The VkPhysicalDeviceConservativeRasterizationPropertiesEXT structure
is defined as:
typedef struct VkPhysicalDeviceConservativeRasterizationPropertiesEXT {
VkStructureType sType;
void* pNext;
float primitiveOverestimationSize;
float maxExtraPrimitiveOverestimationSize;
float extraPrimitiveOverestimationSizeGranularity;
VkBool32 primitiveUnderestimation;
VkBool32 conservativePointAndLineRasterization;
VkBool32 degenerateTrianglesRasterized;
VkBool32 degenerateLinesRasterized;
VkBool32 fullyCoveredFragmentShaderInputVariable;
VkBool32 conservativeRasterizationPostDepthCoverage;
} VkPhysicalDeviceConservativeRasterizationPropertiesEXT;
Members
The members of the
VkPhysicalDeviceConservativeRasterizationPropertiesEXT structure
describe the following implementation-dependent limits:
Description
-
sTypeis the type of this structure. -
pNextisNULLor a pointer to an extension-specific structure. -
primitiveOverestimationSizeis the size in pixels the generating primitive is increased at each of its edges during conservative rasterization overestimation mode. Even with a size of 0.0, conservative rasterization overestimation rules still apply and if any part of the pixel rectangle is covered by the generating primitive, fragments are generated for the entire pixel. However implementations may make the pixel coverage area even more conservative by increasing the size of the generating primitive. -
maxExtraPrimitiveOverestimationSizeis the maximum size in pixels of extra overestimation the implementation supports in the pipeline state. A value of 0.0 means the implementation does not support any additional overestimation of the generating primitive during conservative rasterization. A value above 0.0 allows the application to further increase the size of the generating primitive during conservative rasterization overestimation. -
extraPrimitiveOverestimationSizeGranularityis the granularity of extra overestimation that can be specified in the pipeline state between 0.0 andmaxExtraPrimitiveOverestimationSizeinclusive. A value of 0.0 means the implementation can use the smallest representable non-zero value in the screen space pixel fixed-point grid. -
primitiveUnderestimationis true if the implementation supports theVK_CONSERVATIVE_RASTERIZATION_MODE_UNDERESTIMATE_EXTconservative rasterization mode in addition toVK_CONSERVATIVE_RASTERIZATION_MODE_OVERESTIMATE_EXT. Otherwise the implementation only supportsVK_CONSERVATIVE_RASTERIZATION_MODE_OVERESTIMATE_EXT. -
conservativePointAndLineRasterizationis true if the implementation supports conservative rasterization of point and line primitives as well as triangle primitives. Otherwise the implementation only supports triangle primitives. -
degenerateTrianglesRasterizedis false if the implementation culls primitives generated from triangles that become zero area after they are quantized to the fixed-point rasterization pixel grid.degenerateTrianglesRasterizedis true if these primitives are not culled and the provoking vertex attributes and depth value are used for the fragments. The primitive area calculation is done on the primitive generated from the clipped triangle if applicable. Zero area primitives are backfacing and the application can enable backface culling if desired. -
degenerateLinesRasterizedis false if the implementation culls lines that become zero length after they are quantized to the fixed-point rasterization pixel grid.degenerateLinesRasterizedis true if zero length lines are not culled and the provoking vertex attributes and depth value are used for the fragments. -
fullyCoveredFragmentShaderInputVariableis true if the implementation supports the SPIR-V builtin fragment shader input variableFullyCoveredEXTwhich specifies that conservative rasterization is enabled and the fragment area is fully covered by the generating primitive. -
conservativeRasterizationPostDepthCoverageis true if the implementation supports conservative rasterization with thePostDepthCoverageexecution mode enabled. When supported theSampleMaskbuilt-in input variable will reflect the coverage after the early per-fragment depth and stencil tests are applied even when conservative rasterization is enabled. OtherwisePostDepthCoverageexecution mode must not be used when conservative rasterization is enabled.
If the VkPhysicalDeviceConservativeRasterizationPropertiesEXT
structure is included in the pNext chain of
VkPhysicalDeviceProperties2, it is filled with the
implementation-dependent limits and properties.
See Also
VkBool32, VkStructureType
Document Notes
For more information, see the Vulkan Specification
This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.
Copyright
Copyright (c) 2014-2019 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.