public static bool isRectVisible(Rect rect, int screenW, int screenH)
{
if (rect.right < 0 || rect.top < 0 ||
rect.x > screenW || rect.y > screenH)
return false;
else
return true;
}
//The position is the bottom left corner.
public static Matrix4 matrixPixelProjection(Rect spriteRect, int screenWidth, int screenHeight)
{
//We want the position to be the bottom left corner, so compensate.
//Temporary solution.
//posX -= tileWidth;
//posY -= tileHeight;
//Find projection and UV matrices.
double px = (spriteRect.x + 0.5) / screenWidth * 2.0 - 1.0;
double py = (screenHeight - spriteRect.y + 0.5 - spriteRect.h) / screenHeight * 2.0 - 1.0;
double sx = (double)spriteRect.w / screenWidth;
double sy = (double)spriteRect .h/ screenHeight;
return new Matrix4(new float[] { (float)sx, 0, 0, 0,
0, (float)sy, 0, 0,
0, 0, 0, 0,
(float)(sx+px), (float)(sy+py), 0, 1});
}
public bool overlaps(Rect r)
{
return r.x < (x + w) && (r.x + r.w) >= x &&
r.y < (y + h) && (r.y + r.h) >= y;
}