TouhouGD/render/shader/effect_skew1.gdshader

shader_type spatial;

render_mode blend_add,unshaded,depth_test_disabled;

uniform sampler2D noise;
uniform sampler2D tex_mask : source_color;
uniform float distortionView : hint_range(0.0, 0.3, 0.005) = 0.03;
uniform float speedView : hint_range(0.0, 1.0, 0.005) = 0.5;
uniform sampler2D screenTexture : hint_screen_texture;

void fragment() 
{
	vec2 uv2 = UV - 1.0 * vec2(mod(TIME, 2.0) - 1.0, 0);
	vec4 col_mask = texture(tex_mask, UV);
	
	float noiseValueX  = (texture(noise, UV + (TIME * speedView)).r * 2.0) - 1.0; // Range: -1.0 to 1.0
	float noiseValueY  = (texture(noise, UV + (TIME * speedView)).r * 2.0) - 1.0; // Range: -1.0 to 1.0
	vec2 noiseDistort = vec2(noiseValueX, noiseValueY) * distortionView * col_mask.r;;
	vec3 distortedScreenTexture = vec3(texture(screenTexture, SCREEN_UV + noiseDistort).rgb);
	
	ALBEDO = distortedScreenTexture;
	ALPHA = col_mask.r;
}