gluProject

gluProject
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Name

gluProject — map object coordinates to window coordinates

C Specification

GLint gluProject ( GLdouble objX , GLdouble objY , GLdouble objZ , const GLdouble *model , const GLdouble *proj , const GLint *view , GLdouble* winX , GLdouble* winY , GLdouble* winZ );

Python Specification

gluProject ( objX , objY , objZ , model = None , proj = None , view = None ) → (winX, winY, winZ)

Parameters

objX, objY, objZ: Specify the object coordinates.
model

Description

gluProject transforms the specified object coordinates into window coordinates using model, proj, and view. The result is stored in winX, winY, and winZ. A return value of GL_TRUE indicates success, a return value of GL_FALSE indicates failure.

To compute the coordinates, let v = ( objX objY objZ 1.0 ) represented as a matrix with 4 rows and 1 column. Then gluProject computes v ' as follows:

v ' = P × M × v

where P is the current projection matrix proj, M is the current modelview matrix model (both represented as 4 × 4 matrices in column-major order) and ' × ' represents matrix multiplication.

The window coordinates are then computed as follows:

winX = view ( 0 ) + view ( 2 ) * ( v ' ( 0 ) + 1 ) / 2

winZ = ( v ' ( 2 ) + 1 ) / 2

Python Sample Code