pathfinding rework for now

psx.gdshader

@@ -0,0 +1,72 @@
+shader_type canvas_item;
+
+render_mode unshaded;
+
+#define MAXCOLORS 16
+
+uniform bool enabled = true;
+uniform bool dithering = true;
+uniform int colors : hint_range(1, MAXCOLORS) = 12;
+uniform int dither_size: hint_range(1, 8) = 1;
+
+float dithering_pattern(ivec2 fragcoord) {
+	const float pattern[] = {
+		0.00, 0.50, 0.10, 0.65, 
+		0.75, 0.25, 0.90, 0.35, 
+		0.20, 0.70, 0.05, 0.50, 
+		0.95, 0.40, 0.80, 0.30
+	};
+	
+	int x = fragcoord.x % 4;
+	int y = fragcoord.y % 4;
+	
+	return pattern[y * 4 + x];
+}
+
+float reduce_color(float raw, float dither, int depth) {
+	float div = 1.0 / float(depth);
+	float val = 0.0;
+	int i = 0;
+
+	while (i <= MAXCOLORS)
+	{
+		if (raw > div * (float(i + 1))) {
+			i = i + 1;
+			continue;
+		}
+
+		if (raw * float(depth) - float(i) <= dither * 0.999)
+		{
+			val = div * float(i);
+		} 
+		else
+		{
+			val = div * float(i + 1);
+		}
+		return val;
+
+		i = i+1;
+	}
+
+	return val;
+}
+
+void fragment() {
+	vec4 raw = texture(TEXTURE, SCREEN_UV);
+	ivec2 uv = ivec2(FRAGCOORD.xy / float(dither_size));
+
+	if (enabled == true){
+		float dithering_value = 1.0;
+		if (dithering)
+		{
+			dithering_value = dithering_pattern(uv);
+		}
+		
+		COLOR.r = reduce_color(raw.r, (dithering_value - 0.5) * dithering_value + 0.5, colors - 1);
+		COLOR.g = reduce_color(raw.g, (dithering_value - 0.5) * dithering_value + 0.5, colors - 1);
+		COLOR.b = reduce_color(raw.b, (dithering_value - 0.5) * dithering_value + 0.5, colors - 1);
+
+	} else {
+		COLOR.rgb = raw.rgb;
+	}
+}