crt_filter

crt_filter.shader

shader_type canvas_item;
 
float Less(float x, float value) {
	return 1.0 - step(value, x);
}

// Will return a value of 1 if the 'x' is >= 'lower' && < 'upper'
float Between(float x, float  lower, float upper) {
	return step(lower, x) * (1.0 - step(upper, x));
}

//	Will return a value of 1 if 'x' is >= value
float GEqual(float x, float value) {
	return step(value, x);
}

void fragment() {
	float brightness = 1.25;
	vec2 uv = FRAGCOORD.xy / SCREEN_PIXEL_SIZE.xy;
	uv.y = -uv.y;
	//uv = uv * 0.05;
	
	vec2 uvStep;
	uvStep.x = uv.x / (1.0 / SCREEN_PIXEL_SIZE.x);
	uvStep.x = mod(uvStep.x, 3.0);
	uvStep.y = uv.y / (1.0 / SCREEN_PIXEL_SIZE.y);
	uvStep.y = mod(uvStep.y, 3.0);
	
	vec4 newColour = texture(SCREEN_TEXTURE, SCREEN_UV);
    
	newColour.r = newColour.r * step(1.0, (Less(uvStep.x, 1.0) + Less(uvStep.y, 1.0)));
	newColour.g = newColour.g * step(1.0, (Between(uvStep.x, 1.0, 2.0) + Between(uvStep.y, 1.0, 2.0)));
	newColour.b = newColour.b * step(1.0, (GEqual(uvStep.x, 2.0) + GEqual(uvStep.y, 2.0)));

    
	COLOR = newColour * brightness;
}

#ifdef X_ONLY
newColour.r = newColour.r * Less(uvStep.x, 1.0);
newColour.g = newColour.g * Between(uvStep.x, 1.0, 2.0);
newColour.b = newColour.b * GEqual(uvStep.x, 2.0);
#endif

#ifdef Y_ONLY
newColour.r = newColour.r * Less(uvStep.y, 1.0);
newColour.g = newColour.g * Between(uvStep.y, 1.0, 2.0);
newColour.b = newColour.b * GEqual(uvStep.y, 2.0);
#endif

#ifdef X_AND_Y
newColour.r = newColour.r * step(1.0, (Less(uvStep.x, 1.0) + Less(uvStep.y, 1.0)));
newColour.g = newColour.g * step(1.0, (Between(uvStep.x, 1.0, 2.0) + Between(uvStep.y, 1.0, 2.0)));
newColour.b = newColour.b * step(1.0, (GEqual(uvStep.x, 2.0) + GEqual(uvStep.y, 2.0)));
#endif