Foundation material boundaries

[markkampe]

In the sample Foundation material_mask_plymouth.png there appears to be about a 16 pixel wide boundary between dirt and grass, brown at the border, fading to red or green on either side.

• vertical and horizontal scans to find the border tiles
• crude treatment is to simply every-other-pixel the (8x8) border tiles
• next treatment would know direction of border and have the dilution fade as we moved away from the border
• next treatment would combine vertical and horizontal fading
• I like to think the combination would handle diagonal borders