IFD:All Hail The Pixels/ProcessingSketches: Difference between revisions

IFD:All Hail The Pixels/ProcessingSketches (view source)

Revision as of 17:00, 9 November 2014

2,612 bytes added , 9 November 2014

Added P04 and P05 example sketches

Frederic Gmeiner

213

edits

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 }
+</source>
+<br /><br />
+=== P04 For Loop ===
+<source lang="java">
+/*
+ P04 For-Loop for repeating structures
+ Draw a number of rectangles in a horizontal line and dynamically
+ change the spacing between them according to the y-position of the
+ mouse.
+*/
+// Variable to specify the total numbers of rectangles to be drawn
+int numRects = 10;
+void setup(){
+  size(1000,600);
+  noFill();
+}
+void draw(){
+  // Calculate the distance between each rectangle by
+  // dividing the current mouse position by 10 (or multiply it with 0.1)
+  float distance = mouseX * 0.1;
+  // Reset the background to white
+  background(255);
+  // Move the coordinate system to the vertical center
+  translate(0, height * 0.5);
+  // Repeat the for-loop for the times of "numRects"
+  for(int i=0; i < numRects ; i++  ){
+    // Draw a rectangle at the current origin of the cordinate system (0,0)
+    rect(0,0,10,10);
+    // Move the coordinate system to the right by the number of pixels specified in "distance"
+    translate( distance ,0);
+  }
+}
+</source>
+<br /><br />
+=== P05 2D Grid ===
+<source lang="java">
+/*
+ P05 2D GRID
+ Example to demsonstrate the usage of two nested for loops
+ to create a two dimensional grid pattern. The number of
+ rows and colums is calculated at the startup so that it
+ matches given space (half of the screen size) and the
+ specified spacing between each grid element (defined by
+ the variable "gridSpacing")
+*/
+// Define the spacing of the grid elements
+float gridSpacing = 10;
+// Inititalize variables to store the number of rows and colums
+float numCols;
+float numRows;
+void setup(){
+  size(600,600);
+  // Dynamically calculate the number of colums and rows accoding to the given
+  // stage size and the grid size.
+  numCols = (width * 0.5) / gridSpacing;
+  numRows = (height * 0.5) / gridSpacing;
+}
+void draw(){
+  background(255);
+  // Leave a quater of the stage blank as spacing around the
+  // grid structure.
+  translate(width * 0.25, height * 0.25);
+    // Use two for loops to interate the colums and rows:
+    for(float i=0; i < numCols; i+= 1 ){
+      for(float j=0; j < numRows; j+= 1){
+        // Change the appearance of dots for
+        // even and odd rows
+        if( j % 2 == 0){
+          stroke(0);
+          noFill();
+        }else{
+          fill(255,0,0);
+          noStroke();
+        }
+        // Calculate the actual position of the individual dot:
+        float x = i * gridSpacing;
+        float y = j * gridSpacing;
+        // Draw the ellipse
+        ellipse(x, y, 5, 5);
+      }
+    }
+}
 </source>
 <br /><br />