Bug 801: Refine commit 9a15aad0e5388a4b927e44d3d2ce136f32474bc2 cache TextureSequence's fragment shader hash-code

Adding TextureSequence.getTextureFragmentShaderHashCode() allowing to use a cached hash-code (performance, interface usability).

Implemented in GLMediaPlayerImpl and ImageSequence.

2 files changed, 34 insertions, 1 deletions

diff --git a/src/jogl/classes/com/jogamp/opengl/util/texture/ImageSequence.java b/src/jogl/classes/com/jogamp/opengl/util/texture/ImageSequence.java
index 4622d6975..a2d202d11 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/texture/ImageSequence.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/texture/ImageSequence.java
@@ -52,6 +52,7 @@ public class ImageSequence implements TextureSequence {
     private final int[] texWrapST = { GL.GL_CLAMP_TO_EDGE, GL.GL_CLAMP_TO_EDGE };
     private volatile int frameIdx = 0;
     private volatile boolean manualStepping = false;
+    private int textureFragmentShaderHashCode = 0;
 
     public ImageSequence(final int textureUnit, final boolean useBuildInTexLookup) {
         this.textureUnit = textureUnit;
@@ -173,4 +174,17 @@ public class ImageSequence implements TextureSequence {
           "  return texture2D(image, texCoord);\n"+
           "}\n\n";
     }
+
+    @Override
+    public int getTextureFragmentShaderHashCode() {
+        if( !isTextureAvailable() ) {
+            textureFragmentShaderHashCode = 0;
+            return 0;
+        } else if( 0 == textureFragmentShaderHashCode ) {
+            int hash = 31 + getTextureLookupFragmentShaderImpl().hashCode();
+            hash = ((hash << 5) - hash) + getTextureSampler2DType().hashCode();
+            textureFragmentShaderHashCode = hash;
+        }
+        return textureFragmentShaderHashCode;
+    }
 }
diff --git a/src/jogl/classes/com/jogamp/opengl/util/texture/TextureSequence.java b/src/jogl/classes/com/jogamp/opengl/util/texture/TextureSequence.java
index 88f40e927..ee3b600a5 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/texture/TextureSequence.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/texture/TextureSequence.java
@@ -257,5 +257,24 @@ public interface TextureSequence {
      *
      * @throws IllegalStateException if instance is not initialized
      */
-    public String getTextureLookupFragmentShaderImpl() throws IllegalStateException ;
+    public String getTextureLookupFragmentShaderImpl() throws IllegalStateException;
+
+    /**
+     * Returns the hash code of the strings:
+     * <ul>
+     *   <li>{@link #getTextureLookupFragmentShaderImpl()}</li>
+     *   <li>{@link #getTextureSampler2DType()}</li>
+     * </ul>
+     * <p>
+     * Returns zero if {@link #isTextureAvailable() texture is not available}.
+     * </p>
+     * The returned hash code allows selection of a matching shader program for this {@link TextureSequence} instance.
+     * <p>
+     * </p>
+     * <p>
+     * Implementation shall cache the resulting hash code,
+     * which must be reset to zero if {@link #isTextureAvailable() texture is not available}.
+     * </p>
+     */
+    public int getTextureFragmentShaderHashCode();
 }