void matrixPerspective(float* matrix, float fieldOfView, float aspectRatio, float zNear, float zFar)
{
float ymax, xmax;
ymax = zNear * tanf(fieldOfView * M_PI / 360.0);
xmax = ymax * aspectRatio;
matrixFrustum(matrix, -xmax, xmax, -ymax, ymax, zNear, zFar);
}
// Projection matrix handling - see http://www.opengl.org/wiki/GluPerspective_code
void matrixPerspective(float result[16], float fovy_degrees, float aspect_ratio,
float znear, float zfar)
{
float ymax, xmax;
ymax = znear * tanf(fovy_degrees * PI_FLOAT / 360.0f);
xmax = ymax * aspect_ratio;
matrixFrustum(result, -xmax, xmax, -ymax, ymax, znear, zfar);
}