C Specification
The VkViewport structure is defined as:
// Provided by VK_VERSION_1_0
typedef struct VkViewport {
float x;
float y;
float width;
float height;
float minDepth;
float maxDepth;
} VkViewport;Members
-
xandyare the viewport’s upper left corner (x,y). -
widthandheightare the viewport’s width and height, respectively. -
minDepthandmaxDepthare the depth range for the viewport.
Description
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Note
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Despite their names, |
The framebuffer depth coordinate zf may be represented using
either a fixed-point or floating-point representation.
However, a floating-point representation must be used if the depth/stencil
attachment has a floating-point depth component.
If an m-bit fixed-point representation is used, we assume that it
represents each value , where k ∈ {
0, 1, …, 2m-1 }, as k (e.g. 1.0 is represented in binary as a
string of all ones).
The viewport parameters shown in the above equations are found from these values as
-
ox =
x+width/ 2 -
oy =
y+height/ 2 -
oz =
minDepth -
px =
width -
py =
height -
pz =
maxDepth-minDepth
The application can specify a negative term for height, which has the
effect of negating the y coordinate in clip space before performing the
transform.
When using a negative height, the application should also adjust the
y value to point to the lower left corner of the viewport instead of
the upper left corner.
Using the negative height allows the application to avoid having to
negate the y component of the Position output from the last
pre-rasterization shader
stage.
The width and height of the implementation-dependent maximum viewport dimensions must be greater than or equal to the width and height of the largest image which can be created and attached to a framebuffer.
The floating-point viewport bounds are represented with an implementation-dependent precision.
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.