Proper TileMap Tile UV shader

Standard solution for calculating tile uv based on pixel_size has issue when using animated tiles. To fix this we can rely on vertex coordinates to get proper UV

// Works only if tiles are not animated
vec2 get_cell_uv(vec2 uv, vec2 pixel_size) {
	vec2 ut = uv;
	ut.x = mod(1.0 - uv.x, pixel_size.x / tile_size) / pixel_size.x * tile_size;
	ut.y = mod(1.0 - uv.y, pixel_size.y / tile_size) / pixel_size.y * tile_size;
	return ut;
}

Shader code

shader_type canvas_item;

const vec2 local_uv[] = { vec2(0,0), vec2(0,1), vec2(1,1), vec2(1,0)};
varying vec2 LOCAL_UV;
void vertex() {
	LOCAL_UV = local_uv[VERTEX_ID];
}

void fragment() {
	COLOR = vec4(LOCAL_UV, 0.0, 1.0);
}

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