1 files changed, 65 insertions, 0 deletions
diff --git a/addons/crt_shader/CRTShader.gdshader b/addons/crt_shader/CRTShader.gdshader
new file mode 100644
index 0000000..d7ca24f
--- /dev/null
+++ b/addons/crt_shader/CRTShader.gdshader
@@ -0,0 +1,65 @@
+shader_type canvas_item;
+
+uniform sampler2D screen_texture : hint_screen_texture;
+uniform float screen_width = 1024;
+uniform float screen_height = 600;
+
+// Curvature
+uniform float BarrelPower =1.1;
+// Color bleeding
+uniform float color_bleeding = 1.2;
+uniform float bleeding_range_x = 3;
+uniform float bleeding_range_y = 3;
+// Scanline
+uniform float lines_distance = 4.0;
+uniform float scan_size = 2.0;
+uniform float scanline_alpha = 0.9;
+uniform float lines_velocity = 30.0;
+
+vec2 distort(vec2 p)
+{
+	float angle = p.y / p.x;
+	float theta = atan(p.y,p.x);
+	float radius = pow(length(p), BarrelPower);
+
+	p.x = radius * cos(theta);
+	p.y = radius * sin(theta);
+
+	return 0.5 * (p + vec2(1.0, 1.0));
+}
+
+void get_color_bleeding(inout vec4 current_color,inout vec4 color_left){
+	current_color = current_color * vec4(color_bleeding, 0.5, 1.0 - color_bleeding, 1);
+	color_left = color_left * vec4(1.0 - color_bleeding, 0.5, color_bleeding, 1);
+}
+
+void get_color_scanline(vec2 uv, inout vec4 c, float time){
+	float line_row = floor((uv.y * screen_height/scan_size) + mod(time * lines_velocity, lines_distance));
+	float n = 1.0 - ceil( (mod(line_row,lines_distance) / lines_distance));
+	c = c - n * c * (1.0 - scanline_alpha);
+	c.a = 1.0;
+}
+
+void fragment()
+{
+	vec2 xy = SCREEN_UV * 2.0;
+	xy.x -= 1.0;
+	xy.y -= 1.0;
+
+	float d = length(xy);
+	if(d < 1.5){
+		xy = distort(xy);
+	}
+	else{
+		xy = SCREEN_UV;
+	}
+
+	float pixel_size_x = 1.0/screen_width * bleeding_range_x;
+	float pixel_size_y = 1.0/screen_height * bleeding_range_y;
+	vec4 color_left = texture(screen_texture, xy - vec2(pixel_size_x, pixel_size_y));
+	vec4 current_color = texture(screen_texture, xy);
+	get_color_bleeding(current_color, color_left);
+	vec4 c = current_color + color_left;
+	get_color_scanline(xy,c,TIME);
+	COLOR = c;
+}