added skewX/Y (bug #1448) and fixed bugs in its implementation

android/core/src/processing/core/PApplet.java

@@ -6884,6 +6884,16 @@ public class PApplet extends Activity implements PConstants, Runnable {
   public void scale(float x, float y, float z) {
     g.scale(x, y, z);
   }
+  
+  
+  public void skewX(float angle) {
+    g.skewX(angle);
+  }
+
+
+  public void skewY(float angle) {
+    g.skewY(angle);
+  }
 
 
   public void resetMatrix() {

android/core/src/processing/core/PGraphics.java

@@ -3277,6 +3277,22 @@ public class PGraphics extends PImage implements PConstants {
   public void scale(float x, float y, float z) {
     showMissingWarning("scale");
   }
+  
+  
+  /**
+   * Skew along X axis
+   */
+  public void skewX(float angle) {
+    showMissingWarning("skewX");
+  }
+
+
+  /**
+   * Skew along Y axis
+   */
+  public void skewY(float angle) {
+    showMissingWarning("skewY");
+  }
 
 
   //////////////////////////////////////////////////////////////

android/core/src/processing/core/PGraphicsAndroid2D.java

@@ -1247,6 +1247,16 @@ public class PGraphicsAndroid2D extends PGraphics {
   public void scale(float sx, float sy, float sz) {
     showDepthWarningXYZ("scale");
   }
+  
+  
+  public void skewX(float angle) {
+    canvas.skew((float) Math.tan(angle), 0);
+  }
+
+
+  public void skewY(float angle) {
+    canvas.skew(0, (float) Math.tan(angle));
+  }
 
 
 

android/core/src/processing/core/PGraphicsAndroid3D.java

@@ -2156,9 +2156,29 @@ public class PGraphicsAndroid3D extends PGraphics {
       gl.glScalef(x, y, z);
       modelviewUpdated = false;
     }
-  }  
+  }
+  
+  
+  public void skewX(float angle) {
+    float t = (float) Math.tan(angle);
+    applyMatrix(1, t, 0, 0,
+                0, 1, 0, 0,
+                0, 0, 1, 0,
+                0, 0, 0, 1);
+  }
 
-    //////////////////////////////////////////////////////////////
+
+  public void skewY(float angle) {
+    float t = (float) Math.tan(angle);
+    applyMatrix(1, 0, 0, 0,
+                t, 1, 0, 0,
+                0, 0, 1, 0,
+                0, 0, 0, 1);
+  }  
+  
+
+  
+  //////////////////////////////////////////////////////////////
 
   // MATRIX MORE!
 

android/core/src/processing/core/PMatrix2D.java

@@ -190,12 +190,12 @@ public class PMatrix2D implements PMatrix {
 
 
   public void skewX(float angle) {
-    apply(1, 0, 1,  angle, 0, 0);
+    apply(1, 0, 1,  tan(angle), 0, 0);
   }
 
 
   public void skewY(float angle) {
-    apply(1, 0, 1,  0, angle, 0);
+    apply(1, 0, 1,  0, tan(angle), 0);
   }
 
 
@@ -423,7 +423,8 @@ public class PMatrix2D implements PMatrix {
 
   // TODO make this more efficient, or move into PMatrix2D
   protected boolean isWarped() {
-    return ((m00 != 1) || (m01 != 0) && 
+    // was &&, but changed so skewX and skewY will work
+    return ((m00 != 1) || (m01 != 0) || 
             (m10 != 0) || (m11 != 1));
   }
 
@@ -446,4 +447,8 @@ public class PMatrix2D implements PMatrix {
   private final float cos(float angle) {
     return (float)Math.cos(angle);
   }
+  
+  private final float tan(float angle) {
+    return (float)Math.tan(angle);
+  }
 }

android/todo.txt

@@ -1,4 +1,7 @@
 0182 android
+X added skewX/Y implementation
+X   http://dev.processing.org/bugs/show_bug.cgi?id=1448
+
 
 _ for libraries that don't work with android, don't let them export
 _   e.g. people adding the opengl library when it's not needed