glViewport function
The glViewport function sets the viewport.
void WINAPI glViewport(
GLint x,
GLint y,
GLsizei width,
GLsizei height
);
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x
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The lower-left corner of the viewport rectangle, in pixels. The default is (0,0).
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y
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The lower-left corner of the viewport rectangle, in pixels. The default is (0,0).
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width
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The width of the viewport. When an OpenGL context is first attached to a window, width and height are set to the dimensions of that window.
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height
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The height of the viewport. When an OpenGL context is first attached to a window, width and height are set to the dimensions of that window.
This function does not return a value.
The following error codes can be retrieved by the glGetError function.
Name | Meaning |
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Either width or height was negative. |
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The function was called between a call to glBegin and the corresponding call to glEnd. |
The glViewport function specifies the affine transformation of x and y from normalized device coordinates to window coordinates. Let (xnd , ynd ) be normalized device coordinates. The window coordinates (xw , yw ) are then computed as follows:
Viewport width and height are silently clamped to a range that depends on the implementation. This range is queried by calling glGet with argument GL_MAX_VIEWPORT_DIMS.
The following functions retrieve information related to glViewport:
glGet with argument GL_VIEWPORT
glGet with argument GL_MAX_VIEWPORT_DIMS
Requirement | Value |
---|---|
Minimum supported client |
Windows 2000 Professional [desktop apps only] |
Minimum supported server |
Windows 2000 Server [desktop apps only] |
Header |
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Library |
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DLL |
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