gluPerspective
Author
Hey,
Can neone tell me what is the exact matrix operation applied by
gluPerspective(fovy,aspect,near,far)
I do have some idea but i am not sure how to do the same thing which this command does.
I need to know the exact details so that i can write my own function which does the same thing.(just for learning!!)
Thanx
On course to my first FPS engine , zoooooom
Ripped out of various chunks of code I have on my HDD at the moment (had to modify it for general viewing, but it should work or be close to doing so):
The source code of Mesa3D is helpful for questions like these.
GLfloat some_matrix[4][4];void glFrustum(GLdouble left, GLdouble right, GLdouble bottom, GLdouble top, GLdouble near, GLdouble far) { GLfloat RsubL = right - left; GLfloat TsubB = top - bottom; GLfloat FsubN = far - near; GLfloat Nmul2 = 2.0f * near; some_matrix[0][1] = some_matrix[0][2] = some_matrix[0][3] = some_matrix[1][0] = some_matrix[1][2] = some_matrix[1][3] = some_matrix[3][0] = some_matrix[3][1] = some_matrix[3][3] = 0.0f; some_matrix[2][3] = -1.0f; some_matrix[0][0] = Nmul2 / RsubL; some_matrix[2][0] = (right + left) / RsubL; some_matrix[1][1] = (Nmul2) / TsubB; some_matrix[2][1] = (top + bottom) / TsubB; some_matrix[2][2] = -(far + near) / FsubN; some_matrix[3][2] = (-far * Nmul2) / FsubN;}void gluPerspective(GLdouble fov, GLdouble aspect, GLdouble near, GLdouble far) { GLdouble ymax = near * tan(0.5 * fov); GLdouble ymin = -ymax; GLdouble xmin = ymin * aspect; GLdouble xmax = ymax * aspect; glFrustum(xmin, xmax, ymin, ymax, near, far);}The source code of Mesa3D is helpful for questions like these.
Author
Thanx Mate!!!!!!!!
That helped and i also downloaded the mesa3d source.
On course to my first FPS engine , zoooooom
That helped and i also downloaded the mesa3d source.
On course to my first FPS engine , zoooooom
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