Adding the shader examples

java/examples/Topics/Shaders/SepBlur/SepBlur.pde

@@ -0,0 +1,68 @@
+/**
+ * Separate Blur Shader
+ * 
+ * This blur shader works by applying two successive passes, one horizontal
+ * and the other vertical.
+ * 
+ * Press the mouse to switch between the custom and default shader.
+ */
+
+PShader blur;
+PGraphics src;
+PGraphics pass1, pass2;
+
+void setup() {
+  size(640, 360, P2D);
+  
+  blur = loadShader("blur.glsl");
+  blur.set("blurSize", 9);
+  blur.set("sigma", 5.0f);  
+  
+  src = createGraphics(width, height, P2D); 
+  
+  pass1 = createGraphics(width, height, P2D);
+  pass1.noSmooth();  
+  
+  pass2 = createGraphics(width, height, P2D);
+  pass2.noSmooth();
+}
+
+void draw() {
+  src.beginDraw();
+  src.background(0);
+  src.fill(255);
+  src.ellipse(width/2, height/2, 100, 100);
+  src.endDraw();
+    
+  // Applying the blur shader along the vertical direction   
+  blur.set("horizontalPass", 0);
+  pass1.beginDraw();            
+  pass1.shader(blur);  
+  pass1.image(src, 0, 0);
+  pass1.endDraw();
+  
+  // Applying the blur shader along the horizontal direction      
+  blur.set("horizontalPass", 1);
+  pass2.beginDraw();            
+  pass2.shader(blur);  
+  pass2.image(pass1, 0, 0);
+  pass2.endDraw();    
+        
+  image(pass2, 0, 0);   
+}
+
+void keyPressed() {
+  if (key == '9') {
+    blur.set("blurSize", 9);
+    blur.set("sigma", 5.0);
+  } else if (key == '7') {
+    blur.set("blurSize", 7);
+    blur.set("sigma", 3.0);
+  } else if (key == '5') {
+    blur.set("blurSize", 5);
+    blur.set("sigma", 2.0);  
+  } else if (key == '3') {
+    blur.set("blurSize", 5);
+    blur.set("sigma", 1.0);  
+  }  
+}