Added blurring 🎉

src/render/Shaders.hpp

@@ -138,6 +138,107 @@ void main() {
 	gl_FragColor = vec4(texture2D(tex, v_texcoord).rgb, 1.0) * alpha;
 })#";
 
+// thanks to Loadus
+// https://www.shadertoy.com/view/Mtl3Rj
+// for this pseudo-gaussian blur!
+inline const std::string FRAGBLUR1 = R"#(
+precision mediump float;
+varying vec2 v_texcoord; // is in 0-1
+uniform sampler2D tex;
+
+uniform float radius;
+uniform vec2 resolution;
+uniform float alpha;
+
+float SCurve (float x) {
+	x = x * 2.0 - 1.0;
+	return -x * abs(x) * 0.5 + x + 0.5;
+}
+
+vec4 BlurH (vec2 size, vec2 uv) {
+	if (radius >= 1.0) {
+		vec4 A = vec4(0.0); 
+		vec4 C = vec4(0.0); 
+
+		float width = 1.0 / size.x;
+
+		float divisor = 0.0; 
+        float weight = 0.0;
+        
+        float radiusMultiplier = 1.0 / radius;
+        
+		for (float x = -radius; x <= radius; x++) {
+			A = texture2D(tex, uv + vec2(x * width, 0.0));
+            
+            weight = SCurve(1.0 - (abs(x) * radiusMultiplier)); 
+            
+            C += A * weight; 
+            
+			divisor += weight; 
+		}
+
+		return vec4(C.r / divisor, C.g / divisor, C.b / divisor, 1.0);
+	}
+
+	return texture2D(tex, uv);
+}
+
+
+void main() {
+	gl_FragColor = BlurH(resolution, v_texcoord) * alpha;
+}
+
+)#";
+
+inline const std::string FRAGBLUR2 = R"#(
+precision mediump float;
+varying vec2 v_texcoord; // is in 0-1
+uniform sampler2D tex;
+
+uniform float radius;
+uniform vec2 resolution;
+uniform float alpha;
+
+float SCurve (float x) {
+	x = x * 2.0 - 1.0;
+	return -x * abs(x) * 0.5 + x + 0.5;
+}
+
+vec4 BlurV (vec2 size, vec2 uv) {
+	if (radius >= 1.0) {
+		vec4 A = vec4(0.0); 
+		vec4 C = vec4(0.0); 
+
+		float height = 1.0 / size.y;
+
+		float divisor = 0.0; 
+        float weight = 0.0;
+        
+        float radiusMultiplier = 1.0 / radius;
+        
+		for (float y = -radius; y <= radius; y++) {
+			A = texture2D(tex, uv + vec2(0.0, y * height));
+            
+            weight = SCurve(1.0 - (abs(y) * radiusMultiplier)); 
+            
+            C += A * weight; 
+            
+			divisor += weight; 
+		}
+
+		return vec4(C.r / divisor, C.g / divisor, C.b / divisor, 1.0);
+	}
+
+	return texture2D(tex, uv);
+}
+
+
+void main() {
+	gl_FragColor = BlurV(resolution, v_texcoord) * alpha;
+}
+
+)#";
+
 inline const std::string TEXFRAGSRCEXT = R"#(
 #extension GL_OES_EGL_image_external : require
 
@@ -189,4 +290,4 @@ void main() {
 	}
 
 	gl_FragColor = texture2D(texture0, v_texcoord) * alpha;
-})#";
+})#";