Product specifications

VT8601A Apollo PLE133
Revision 1.82 October 22, 2001 -123 3D Graphics Engine Registers
Technologies, Inc.
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Texture Coordinate Parameters
Texture parameters are used for texture mapping. They
consist of starting values, incremental along the X and Y axis.
DoubleWord 0 – Initial U Value
31-0 Initial U Value
Initial U value on main edge (left edge of trapezoid
or long edge of triangle). Signed 16.16 integer.
DoubleWord 1 – Initial U Value
31-0 Initial U Value
Initial U value on main edge (left edge of trapezoid
or long edge of triangle). Signed 16.16 integer.
DoubleWord 2 – X-Axis U Gradient
31-0 X-Axis U Gradient
Gradient of U along the X axis over the primitive
surface. Signed 16.16 number.
DoubleWord 3 – Y-Axis U Gradient
31-0 Y-Axis U Gradient
Gradient of U along the Y axis over the primitive
surface. Signed 16.16 number.
DoubleWord 4 – X-Axis V Gradient
31-0 X-Axis V Gradient
Gradient of V along the X axis over the primitive
surface. Signed 16.16 number.
DoubleWord 5 – Y-Axis V Gradient
31-0 Y-Axis V Gradient
Gradient of V along the Y axis over the primitive
surface. Signed 16.16 number.
Perspective Factor Parameters
Perspective factor parameters are used for perspective
corrected texture mapping. They consist of W starting values
incremental along the X and Y axis.
DoubleWord 0 – Initial W Value
31-0 Initial W Value
Initial W value on main edge (left edge of trapezoid
or long edge of triangle). Signed 4.28 integer.
DoubleWord 1 – X-Axis W Gradient
31-0 X-Axis W Gradient
Gradient of W along the X axis over the primitive
surface. Signed 4.28 number.
DoubleWord 2 – Y-Axis W Gradient
31-0 Y-Axis W Gradient
Gradient of W along the Y axis over the primitive
surface. Signed 4.28 number.