void fzMath_mat4PerspectiveProjection(fzFloat fovY, fzFloat aspect,
fzFloat zNear, fzFloat zFar,
float *output)
{
FZ_ASSERT(output != NULL, "Output matrix cannot be NULL.");
fzFloat r = FZ_DEGREES_TO_RADIANS(fovY / 2);
fzFloat deltaZ = zFar - zNear;
fzFloat s = fzMath_sin(r);
fzFloat cotangent = 0;
if (deltaZ == 0 || s == 0 || aspect == 0) {
FZLOGERROR("Perpertive impossible.");
return;
}
cotangent = fzMath_cos(r) / s;
fzMath_mat4Identity(output);
output[0] = cotangent / aspect;
output[5] = cotangent;
output[10] = -(zFar + zNear) / deltaZ;
output[11] = -1;
output[14] = -2 * zNear * zFar / deltaZ;
output[15] = 0;
}
void fzMath_mat4LookAt(const fzPoint3& eye, const fzPoint3& center, const fzPoint3& up, float *output)
{
FZ_ASSERT(output != NULL, "Output pointer cannot be NULL.");
fzPoint3 f(center);
f.x -= eye.x;
f.y -= eye.y;
f.z -= eye.z;
f.normalize();
fzPoint3 up2(up);
up2.normalize();
fzPoint3 s(f.getCrossed(up2));
s.normalize();
fzPoint3 u(s.getCrossed(f));
//s.normalize();
u.normalize();
fzMath_mat4Identity(output);
output[0] = s.x;
output[4] = s.y;
output[8] = s.z;
output[1] = u.x;
output[5] = u.y;
output[9] = u.z;
output[2] = -f.x;
output[6] = -f.y;
output[10] = -f.z;
/*
fzMat4 translationMatrix;
fzAffineTransform translate(FZAffineTransformIdentity);
translate.translate(-eye.x, -eye.y);
translate.setZ(-eye.y);
*/
/*
fzMath_mat4Multiply(<#const fzFloat *mIn1#>, <#const fzFloat *mIn2#>, <#fzFloat *mOut#>)
fzMath_mat4Multiply(output, translate, output);
*/
// kmMat4 translate;
// kmMat4Translation(&translate, -pEye->x, -pEye->y, -pEye->z);
// kmMat4Multiply(pOut, pOut, &translate);
}
void fzMath_mat4LookAt(const fzPoint3& eye, const fzPoint3& center, const fzPoint3& up, float *output)
{
FZ_ASSERT(output != NULL, "Output pointer cannot be NULL.");
fzPoint3 f(center);
f -= eye;
f.normalize();
fzPoint3 up2(up);
up2.normalize();
fzPoint3 s = f.getCrossed(up2);
s.normalize();
fzPoint3 u(s.getCrossed(f));
// u.normalize();
//s.normalize();
fzMath_mat4Identity(output);
output[0] = s.x; //1
output[4] = s.y;
output[8] = s.z;
output[1] = u.x;
output[5] = u.y; // 1
output[9] = u.z;
output[2] = -f.x;
output[6] = -f.y;
output[10] = -f.z; // 1
float x = -eye.x; //mat[12]
float y = -eye.y; //mat[13]
float z = -eye.z; //mat[14]
float mat[4];
mat[0] = output[0] * x + output[4] * y + output[8] * z + output[12];
mat[1] = output[1] * x + output[5] * y + output[9] * z + output[13];
mat[2] = output[2] * x + output[6] * y + output[10] * z + output[14];
mat[3] = output[3] * x + output[7] * y + output[11] * z + output[15];
memcpy(&output[12], mat, sizeof(float)*4);
}
void fzMath_mat4OrthoProjection(fzFloat left, fzFloat right,
fzFloat bottom, fzFloat top,
fzFloat nearVal, fzFloat farVal,
float* output )
{
FZ_ASSERT(output != NULL, "Output pointer cannot be NULL.");
fzFloat tx = -((right + left) / (right - left));
fzFloat ty = -((top + bottom) / (top - bottom));
fzFloat tz = -((farVal + nearVal) / (farVal - nearVal));
fzMath_mat4Identity(output);
output[0] = 2 / (right - left);
output[5] = 2 / (top - bottom);
output[10] = -2 / (farVal - nearVal);
output[12] = tx;
output[13] = ty;
output[14] = tz;
}
