Bug 731570 - Rename and make default shaders public. r=pcwalton

Rename and make public the default shaders used in LayerRenderer, and make
loadShader a public, static method. This should make it easier for layers to
implement their own shader programs.

mobile/android/base/gfx/GeckoLayerClient.java

@@ -353,7 +353,7 @@ public class GeckoLayerClient implements GeckoEventResponder,
         // Create the shaders and textures if necessary.
         if (!mLayerRendererInitialized) {
             mLayerRenderer.checkMonitoringEnabled();
-            mLayerRenderer.createProgram();
+            mLayerRenderer.createDefaultProgram();
             mLayerRendererInitialized = true;
         }
 
@@ -365,12 +365,12 @@ public class GeckoLayerClient implements GeckoEventResponder,
 
     /** This function is invoked by Gecko via JNI; be careful when modifying signature. */
     public void activateProgram() {
-        mLayerRenderer.activateProgram();
+        mLayerRenderer.activateDefaultProgram();
     }
 
     /** This function is invoked by Gecko via JNI; be careful when modifying signature. */
     public void deactivateProgram() {
-        mLayerRenderer.deactivateProgram();
+        mLayerRenderer.deactivateDefaultProgram();
     }
 
     /** Implementation of FlexibleGLSurfaceView.Listener */

mobile/android/base/gfx/LayerRenderer.java

@@ -126,7 +126,7 @@ public class LayerRenderer implements GLSurfaceView.Renderer {
     // column-major matrix applied to each vertex to shift the viewport from
     // one ranging from (-1, -1),(1,1) to (0,0),(1,1) and to scale all sizes by
     // a factor of 2 to fill up the screen
-    private static final float[] TEXTURE_MATRIX = {
+    public static final float[] DEFAULT_TEXTURE_MATRIX = {
         2.0f, 0.0f, 0.0f, 0.0f,
         0.0f, 2.0f, 0.0f, 0.0f,
         0.0f, 0.0f, 2.0f, 0.0f,
@@ -137,7 +137,7 @@ public class LayerRenderer implements GLSurfaceView.Renderer {
 
     // The shaders run on the GPU directly, the vertex shader is only applying the
     // matrix transform detailed above
-    private static final String VERTEX_SHADER =
+    public static final String DEFAULT_VERTEX_SHADER =
         "uniform mat4 uTMatrix;\n" +
         "attribute vec4 vPosition;\n" +
         "attribute vec2 aTexCoord;\n" +
@@ -150,7 +150,7 @@ public class LayerRenderer implements GLSurfaceView.Renderer {
     // Note we flip the y-coordinate in the fragment shader from a
     // coordinate system with (0,0) in the top left to one with (0,0) in
     // the bottom left.
-    private static final String FRAGMENT_SHADER =
+    public static final String DEFAULT_FRAGMENT_SHADER =
         "precision mediump float;\n" +
         "varying vec2 vTexCoord;\n" +
         "uniform sampler2D sTexture;\n" +
@@ -188,13 +188,13 @@ public class LayerRenderer implements GLSurfaceView.Renderer {
 
     public void onSurfaceCreated(GL10 gl, EGLConfig config) {
         checkMonitoringEnabled();
-        createProgram();
-        activateProgram();
+        createDefaultProgram();
+        activateDefaultProgram();
     }
 
-    public void createProgram() {
-        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, VERTEX_SHADER);
-        int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, FRAGMENT_SHADER);
+    public void createDefaultProgram() {
+        int vertexShader = loadShader(GLES20.GL_VERTEX_SHADER, DEFAULT_VERTEX_SHADER);
+        int fragmentShader = loadShader(GLES20.GL_FRAGMENT_SHADER, DEFAULT_FRAGMENT_SHADER);
 
         mProgram = GLES20.glCreateProgram();
         GLES20.glAttachShader(mProgram, vertexShader);   // add the vertex shader to program
@@ -213,12 +213,12 @@ public class LayerRenderer implements GLSurfaceView.Renderer {
     }
 
     // Activates the shader program.
-    public void activateProgram() {
+    public void activateDefaultProgram() {
         // Add the program to the OpenGL environment
         GLES20.glUseProgram(mProgram);
 
         // Set the transformation matrix
-        GLES20.glUniformMatrix4fv(mTMatrixHandle, 1, false, TEXTURE_MATRIX, 0);
+        GLES20.glUniformMatrix4fv(mTMatrixHandle, 1, false, DEFAULT_TEXTURE_MATRIX, 0);
 
         Log.e(LOGTAG, "### Position handle is " + mPositionHandle + ", texture handle is " +
               mTextureHandle + ", last error is " + GLES20.glGetError());
@@ -237,7 +237,7 @@ public class LayerRenderer implements GLSurfaceView.Renderer {
 
     // Deactivates the shader program. This must be done to avoid crashes after returning to the
     // Gecko C++ compositor from Java.
-    public void deactivateProgram() {
+    public void deactivateDefaultProgram() {
         GLES20.glDisableVertexAttribArray(mTextureHandle);
         GLES20.glDisableVertexAttribArray(mPositionHandle);
         GLES20.glUseProgram(0);
@@ -445,7 +445,7 @@ public class LayerRenderer implements GLSurfaceView.Renderer {
      * create a vertex shader type (GLES20.GL_VERTEX_SHADER)
      * or a fragment shader type (GLES20.GL_FRAGMENT_SHADER)
      */
-    private int loadShader(int type, String shaderCode) {
+    public static int loadShader(int type, String shaderCode) {
         int shader = GLES20.glCreateShader(type);
         GLES20.glShaderSource(shader, shaderCode);
         GLES20.glCompileShader(shader);