Implement lighting (exercise 1.4)

Add "L" debugging key to toggle lighting. If it is buggy, see pitfall
14 at http://www.opengl.org/archives/resources/features/KilgardTechniques/oglpitfall/

1 files changed, 65 insertions, 3 deletions

diff --git a/src/RobotRace.java b/src/RobotRace.java
index c755225..9dfda81 100644
--- a/src/RobotRace.java
+++ b/src/RobotRace.java
@@ -86,6 +86,12 @@ public class RobotRace extends Base {
     private final Terrain terrain;
 
     /**
+     * Whether lighting effects should be enabled or not. For testing purposes,
+     * defaults to true. It can be changed by pressing "L".
+     */
+    private boolean lightingEnabled = true;
+
+    /**
      * Constructs this robot race by initializing robots, camera, track, and
      * terrain.
      */
@@ -150,6 +156,35 @@ public class RobotRace extends Base {
         gl.glEnable(GL_TEXTURE_2D);
         gl.glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);
         gl.glBindTexture(GL_TEXTURE_2D, 0);
+
+        // initialize lighting effects (lighting bit is not enabled here though)
+        initLighting();
+    }
+
+    /**
+     * Set lighting colors and effects, but do not enable them yet.
+     */
+    private void initLighting() {
+        // greyish color
+        float[] ambientRGBA = {0.2f, 0.2f, 0.2f, 1.0f};
+        // yellowish - "sunglow" RGB (255, 204, 51)
+        //float[] diffuseRGBA = {1.0f, 0.8f, 0.2f, 1.0f};
+        // red!
+        float[] diffuseRGBA = {1.0f, 0.0f, 0.0f, 1.0f};
+
+        // set the light-source colors
+        gl.glLightfv(GL_LIGHT0, GL_AMBIENT, ambientRGBA, 0);
+        gl.glLightfv(GL_LIGHT0, GL_DIFFUSE, diffuseRGBA, 0);
+
+        // global ambient light
+        //gl.glLightModelfv(GL_LIGHT_MODEL_AMBIENT, ambientRGBA, 0);
+
+        // turn the light on (note: display func must set or unset LIGHTING)
+        gl.glEnable(GL_LIGHT0);
+        //gl.glEnable(GL_LIGHTING);
+
+        // blend the light with the material colors
+        gl.glEnable(GL_COLOR_MATERIAL);
     }
 
     /**
@@ -185,6 +220,26 @@ public class RobotRace extends Base {
         glu.gluLookAt(camera.eye.x(), camera.eye.y(), camera.eye.z(),
                 camera.center.x(), camera.center.y(), camera.center.z(),
                 camera.up.x(), camera.up.y(), camera.up.z());
+
+        // Enable lighting effects
+        if (lightingEnabled) {
+            float[] lightPos = {
+                // light position (slightly away from top-left corner)
+                (float) camera.eye.x(),
+                (float) camera.eye.y() + 1f,
+                (float) camera.eye.z() - 1f,
+                // Light-source type, 0 sets a directional light which starts in
+                // (x,y,z) and points to the origin. 1 means positional where
+                // the light is located in (x,y,z) and shines in all directions.
+                0
+            };
+
+            // set the light-source position
+            gl.glLightfv(GL_LIGHT0, GL_POSITION, lightPos, 0);
+            gl.glEnable(GL_LIGHTING);
+        } else {
+            gl.glDisable(GL_LIGHTING);
+        }
     }
 
     /**
@@ -300,20 +355,27 @@ public class RobotRace extends Base {
      * implementation.
      */
     public static void main(String args[]) {
+        System.out.println("JOGL version: "
+                + com.jogamp.opengl.JoglVersion.getInstance().getImplementationBuild());
+        final RobotRace robotRace = new RobotRace();
         // Being able to exit by pressing Escape would be nice.
         KeyboardFocusManager.getCurrentKeyboardFocusManager().addKeyEventDispatcher(new KeyEventDispatcher() {
             @Override
             public boolean dispatchKeyEvent(KeyEvent e) {
+                if (e.getID() != KeyEvent.KEY_PRESSED) {
+                    return false;
+                }
                 if (e.getKeyCode() == KeyEvent.VK_ESCAPE) {
                     System.err.println("Exiting...");
                     System.exit(0);
                     return true;
                 }
+                if (e.getKeyCode() == KeyEvent.VK_L) {
+                    robotRace.lightingEnabled = !robotRace.lightingEnabled;
+                    System.err.println("Lighting set to " + robotRace.lightingEnabled);
+                }
                 return false;
             }
         });
-        System.out.println("JOGL version: "
-                + com.jogamp.opengl.JoglVersion.getInstance().getImplementationBuild());
-        RobotRace robotRace = new RobotRace();
     }
 }