Function CheckPartialPixelZSlopeAddition

src/tests/landscape_partial_pixel_z.cpp:28–39

* Check whether the addition of two slope's GetPartialPixelZ values results in * the GetPartialPixelZ values of the expected slope. * This iterates over all sub-pixel locations within a single tile. * @param slope_expected The slope that is expected. * @param slope_a The first slope of the addition. * @param slope_b The second slope of the addition. * @return True iff at all GetPartialPixelZ

 * @return True iff at all GetPartialPixelZ results are the same for each sub-tile position.
 */
bool CheckPartialPixelZSlopeAddition(Slope slope_expected, Slope slope_a, Slope slope_b)
{
	for (uint x = 0; x < TILE_SIZE; x++) {
		for (uint y = 0; y < TILE_SIZE; y++) {
			int z_a = GetPartialPixelZ(x, y, slope_a);
			int z_b = GetPartialPixelZ(x, y, slope_b);
			int z_result = GetPartialPixelZ(x, y, slope_expected);
			if (z_result != z_a + z_b) return false;
		}
	}
	return true;
}

TEST_CASE("PartialPixelSlopeAdditionTest - A one corner slope, plus the opposite three corner slope results in a flat but elevated slope")
{