setPerspectiveMatrix function
void
setPerspectiveMatrix()
Constructs an OpenGL perspective projection matrix in perspectiveMatrix
.
fovYRadians
specifies the field of view angle, in radians, in the y
direction.
aspectRatio
specifies the aspect ratio that determines the field of view
in the x direction. The aspect ratio of x (width) to y (height).
zNear
specifies the distance from the viewer to the near plane
(always positive).
zFar
specifies the distance from the viewer to the far plane
(always positive).
Implementation
void setPerspectiveMatrix(Matrix4 perspectiveMatrix, double fovYRadians,
double aspectRatio, double zNear, double zFar) {
final height = math.tan(fovYRadians * 0.5);
final width = height * aspectRatio;
final near_minus_far = zNear - zFar;
perspectiveMatrix
..setZero()
..setEntry(0, 0, 1.0 / width)
..setEntry(1, 1, 1.0 / height)
..setEntry(2, 2, (zFar + zNear) / near_minus_far)
..setEntry(3, 2, -1.0)
..setEntry(2, 3, (2.0 * zNear * zFar) / near_minus_far);
}