Vec2 cameraWorldToScreenPoint(Camera *cam, Vec3 worldPos)
{
Vec4 worldCoord = vec4FromVec3AndW(worldPos, 1.0);
Mat4 viewProjection;
mat4Mul(&viewProjection, &cam->perspectiveMatrix, &cam->transformMatrix);
Vec4 ret4;
mat4Vec4Mul(&ret4, &viewProjection, &worldCoord);
vec4Scale(&ret4, &ret4, 1.0/ret4.w);
Vec2 ret;
ret.x = ret4.x;
ret.y = ret4.y;
return ret;
}
Vec3 cameraScreenDepthToWorldPoint(Camera *cam, Vec2 screenPos, r32 depth)
{
Vec4 screenCoord = vec4(screenPos.x, screenPos.y, depth, 1.0);
Mat4 mat = cameraCalculateInverseViewMatrix(cam);
Mat4 mat2 = invPerspective(&cam->perspectiveMatrix);
Mat4 camInvPerspective;
mat4Mul(&camInvPerspective, &mat, &mat2);
Vec4 ret4;
mat4Vec4Mul(&ret4, &camInvPerspective, &screenCoord);
vec4Scale(&ret4, &ret4, 1.0/ret4.w);
return vec3FromVec4(ret4);
}
vec4 vec4Subtract(const vec4 aVec, const vec4 bVec)
{
return vec4Add(aVec, vec4Scale(-1., bVec));
}
vec4 vec4Mix(const vec4 aVec, const vec4 bVec, const GLfloat blend)
{
return vec4Add(vec4Scale(blend, aVec),
vec4Scale(1. - blend, bVec));
}
vec4 vec4Normalize(const vec4 inVec)
{
return vec4Scale(1.0f/vec4Magnitude(inVec), inVec);
}
