Bug 962 - AWTGLReadBufferUtil should use aligned BufferedImage [for resized images]; Fix GLReadBufferUtil GL_PACK_ROW_LENGTH

AWTGLPixelBuffer is being reused when used via AWTGLPixelBufferProvider
even when resized.

AWTGLPixelBufferProvider uses  GLPixelBufferProvider's requiresNewBuffer(..)
which returns true if
  - allowRowStride==true and pixel-buffer size < required-size, or
  - allowRowStride==false and pixel-buffer size < required _or_ width doesn't match

otherwise it returns true, i.e. the AWTGLPixelBuffer is reused.

Hence the used BufferedImage might need to be aligned,
i.e. using AWTGLPixelBuffer's getAlignedImage(..).

+++

GLReadBufferUtil shall use current texture-data width for GL_PACK_ROW_LENGTH,
not the static GLPixelBuffer's width, which may not reflect image dimension (resize)

+++

3 files changed, 74 insertions, 16 deletions

diff --git a/src/jogl/classes/com/jogamp/opengl/util/GLPixelBuffer.java b/src/jogl/classes/com/jogamp/opengl/util/GLPixelBuffer.java
index a921a2818..223c23ebb 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/GLPixelBuffer.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/GLPixelBuffer.java
@@ -324,9 +324,19 @@ public class GLPixelBuffer {
 
     /** The {@link GLPixelAttributes}. */
     public final GLPixelAttributes pixelAttributes;
-    /** Width in pixels. */
+    /**
+     * Width in pixels, representing {@link #buffer}'s {@link #byteSize}.
+     * <p>
+     * May not represent actual image width as user may re-use buffer for different dimensions, see {@link #requiresNewBuffer(GL, int, int, int)}.
+     * </p>
+     */
     public final int width;
-    /** Height in pixels. */
+    /**
+     * Height in pixels, representing {@link #buffer}'s {@link #byteSize}.
+     * <p>
+     * May not represent actual image height as user may re-use buffer for different dimensions, see {@link #requiresNewBuffer(GL, int, int, int)}.
+     * </p>
+     */
     public final int height;
     /** Depth in pixels. */
     public final int depth;
diff --git a/src/jogl/classes/com/jogamp/opengl/util/GLReadBufferUtil.java b/src/jogl/classes/com/jogamp/opengl/util/GLReadBufferUtil.java
index b942c9ab2..b7d2980df 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/GLReadBufferUtil.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/GLReadBufferUtil.java
@@ -151,17 +151,6 @@ public class GLReadBufferUtil {
      * @see #GLReadBufferUtil(boolean, boolean)
      */
     public boolean readPixels(GL gl, int inX, int inY, int inWidth, int inHeight, boolean mustFlipVertically) {
-        final int glerr0 = gl.glGetError();
-        if(GL.GL_NO_ERROR != glerr0) {
-            System.err.println("Info: GLReadBufferUtil.readPixels: pre-exisiting GL error 0x"+Integer.toHexString(glerr0));
-        }
-        final GLPixelAttributes pixelAttribs = pixelBufferProvider.getAttributes(gl, componentCount);
-        final int internalFormat;
-        if(gl.isGL2GL3() && 3 == componentCount) {
-            internalFormat = GL.GL_RGB;
-        } else {
-            internalFormat = (4 == componentCount) ? GL.GL_RGBA : GL.GL_RGB;
-        }
         final GLDrawable drawable = gl.getContext().getGLReadDrawable();
         final int width, height;
         if( 0 >= inWidth || drawable.getWidth() < inWidth ) {
@@ -174,6 +163,23 @@ public class GLReadBufferUtil {
         } else {
             height= inHeight;
         }
+        return readPixelsImpl(drawable, gl, inX, inY, width, height, mustFlipVertically);
+    }
+
+    protected boolean readPixelsImpl(final GLDrawable drawable, final GL gl,
+                                     final int inX, final int inY, final int width, final int height,
+                                     final boolean mustFlipVertically) {
+        final int glerr0 = gl.glGetError();
+        if(GL.GL_NO_ERROR != glerr0) {
+            System.err.println("Info: GLReadBufferUtil.readPixels: pre-exisiting GL error 0x"+Integer.toHexString(glerr0));
+        }
+        final GLPixelAttributes pixelAttribs = pixelBufferProvider.getAttributes(gl, componentCount);
+        final int internalFormat;
+        if(gl.isGL2GL3() && 3 == componentCount) {
+            internalFormat = GL.GL_RGB;
+        } else {
+            internalFormat = (4 == componentCount) ? GL.GL_RGBA : GL.GL_RGB;
+        }
 
         final boolean flipVertically;
         if( drawable.isGLOriented() ) {
@@ -216,7 +222,7 @@ public class GLReadBufferUtil {
         if(res) {
             psm.setAlignment(gl, alignment, alignment);
             if(gl.isGL2GL3()) {
-                gl.getGL2GL3().glPixelStorei(GL2GL3.GL_PACK_ROW_LENGTH, readPixelBuffer.width);
+                gl.getGL2GL3().glPixelStorei(GL2GL3.GL_PACK_ROW_LENGTH, width);
             }
             readPixelBuffer.clear();
             try {
diff --git a/src/jogl/classes/com/jogamp/opengl/util/awt/AWTGLReadBufferUtil.java b/src/jogl/classes/com/jogamp/opengl/util/awt/AWTGLReadBufferUtil.java
index f5d31a132..9490e041b 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/awt/AWTGLReadBufferUtil.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/awt/AWTGLReadBufferUtil.java
@@ -30,6 +30,7 @@ package com.jogamp.opengl.util.awt;
 import java.awt.image.BufferedImage;
 
 import javax.media.opengl.GL;
+import javax.media.opengl.GLDrawable;
 import javax.media.opengl.GLProfile;
 
 import com.jogamp.opengl.util.GLReadBufferUtil;
@@ -51,12 +52,53 @@ public class AWTGLReadBufferUtil extends GLReadBufferUtil {
 
     public AWTGLPixelBuffer getAWTGLPixelBuffer() { return (AWTGLPixelBuffer)this.getPixelBuffer(); }
 
+    /**
+     * Read the drawable's pixels to TextureData and Texture, if requested at construction,
+     * and returns an aligned {@link BufferedImage}.
+     *
+     * @param gl the current GL context object. It's read drawable is being used as the pixel source.
+     * @param awtOrientation flips the data vertically if <code>true</code>.
+     *                       The context's drawable {@link GLDrawable#isGLOriented()} state
+     *                       is taken into account.
+     *                       Vertical flipping is propagated to TextureData
+     *                       and handled in a efficient manner there (TextureCoordinates and TextureIO writer).
+     * @see #AWTGLReadBufferUtil(GLProfile, boolean)
+     */
     public BufferedImage readPixelsToBufferedImage(GL gl, boolean awtOrientation) {
         return readPixelsToBufferedImage(gl, 0, 0, 0, 0, awtOrientation);
     }
+
+    /**
+     * Read the drawable's pixels to TextureData and Texture, if requested at construction,
+     * and returns an aligned {@link BufferedImage}.
+     *
+     * @param gl the current GL context object. It's read drawable is being used as the pixel source.
+     * @param inX readPixel x offset
+     * @param inY readPixel y offset
+     * @param inWidth optional readPixel width value, used if [1 .. drawable.width], otherwise using drawable.width
+     * @param inHeight optional readPixel height, used if [1 .. drawable.height], otherwise using drawable.height
+     * @param awtOrientation flips the data vertically if <code>true</code>.
+     *                       The context's drawable {@link GLDrawable#isGLOriented()} state
+     *                       is taken into account.
+     *                       Vertical flipping is propagated to TextureData
+     *                       and handled in a efficient manner there (TextureCoordinates and TextureIO writer).
+     * @see #AWTGLReadBufferUtil(GLProfile, boolean)
+     */
     public BufferedImage readPixelsToBufferedImage(GL gl, int inX, int inY, int inWidth, int inHeight, boolean awtOrientation) {
-        if( readPixels(gl, inX, inY, inWidth, inHeight, awtOrientation) ) {
-            final BufferedImage image = getAWTGLPixelBuffer().image;
+        final GLDrawable drawable = gl.getContext().getGLReadDrawable();
+        final int width, height;
+        if( 0 >= inWidth || drawable.getWidth() < inWidth ) {
+            width = drawable.getWidth();
+        } else {
+            width = inWidth;
+        }
+        if( 0 >= inHeight || drawable.getHeight() < inHeight ) {
+            height = drawable.getHeight();
+        } else {
+            height= inHeight;
+        }
+        if( readPixelsImpl(drawable, gl, inX, inY, width, height, awtOrientation) ) {
+            final BufferedImage image = getAWTGLPixelBuffer().getAlignedImage(width, height);
             if( getTextureData().getMustFlipVertically()  ) {
                 ImageUtil.flipImageVertically(image);
             }