Vector to PixelArt

shader_type canvas_item;

// Controls for pixelation effect
uniform float pixel_size : hint_range(1.0, 32.0) = 8.0;
uniform float color_levels : hint_range(2.0, 256.0) = 16.0;
uniform bool enable_posterize = true;
uniform bool enable_edge_detection = false;
uniform float edge_threshold : hint_range(0.0, 1.0) = 0.3;
uniform float edge_darkness : hint_range(0.0, 1.0) = 0.5;

void fragment() {
	vec2 uv = UV;

	// Pixelate: round UVs to nearest pixel block
	vec2 pixelated_uv = floor(uv * vec2(textureSize(TEXTURE, 0)) / pixel_size) * pixel_size / vec2(textureSize(TEXTURE, 0));

	// Sample the pixelated texture
	vec4 color = texture(TEXTURE, pixelated_uv);

	// Posterize: reduce color palette
	if (enable_posterize) {
		color.rgb = floor(color.rgb * color_levels) / color_levels;
	}

	// Optional edge detection for harder lines
	if (enable_edge_detection) {
		// Sample neighboring pixels
		vec2 pixel_step = 1.0 / vec2(textureSize(TEXTURE, 0));

		vec4 up = texture(TEXTURE, pixelated_uv + vec2(0.0, pixel_step.y));
		vec4 down = texture(TEXTURE, pixelated_uv - vec2(0.0, pixel_step.y));
		vec4 left = texture(TEXTURE, pixelated_uv - vec2(pixel_step.x, 0.0));
		vec4 right = texture(TEXTURE, pixelated_uv + vec2(pixel_step.x, 0.0));

		// Calculate edge strength
		float edge = abs(color.r - up.r) + abs(color.r - down.r) +
		             abs(color.r - left.r) + abs(color.r - right.r);

		if (edge > edge_threshold) {
			color.rgb *= (1.0 - edge_darkness);
		}
	}

	COLOR = color;
}