fix issue: #5,#6 and refactor code slightly

Author: eschao

.idea/gradle.xml

@@ -35,16 +35,16 @@ public class FoldBackVertexProgram extends VertexProgram {
     final static String VAR_MASK_COLOR     = "u_maskColor";
     final static String VAR_SHADOW_TEXTURE = "u_shadow";
 
-    int hShadow;
-    int hMaskColor;
-    int hTexXOffset;
+    int mShadowLoc;
+    int mMaskColorLoc;
+    int mTexXOffsetLoc;
 
     public FoldBackVertexProgram() {
         super();
 
-        hShadow = INVALID_HANDLE;
-        hMaskColor = INVALID_HANDLE;
-        hTexXOffset = INVALID_HANDLE;
+        mShadowLoc = INVALID_GL_HANDLE;
+        mMaskColorLoc = INVALID_GL_HANDLE;
+        mTexXOffsetLoc = INVALID_GL_HANDLE;
     }
 
     /**
@@ -68,10 +68,11 @@ public FoldBackVertexProgram init(Context context) throws
     protected void getVarsLocation() {
         super.getVarsLocation();
 
-        if (hProgram != 0) {
-            hShadow = glGetUniformLocation(hProgram, VAR_SHADOW_TEXTURE);
-            hMaskColor = glGetUniformLocation(hProgram, VAR_MASK_COLOR);
-            hTexXOffset = glGetUniformLocation(hProgram, VAR_TEXTRUE_OFFSET);
+        if (mProgramRef != 0) {
+            mShadowLoc = glGetUniformLocation(mProgramRef, VAR_SHADOW_TEXTURE);
+            mMaskColorLoc = glGetUniformLocation(mProgramRef, VAR_MASK_COLOR);
+            mTexXOffsetLoc = glGetUniformLocation(mProgramRef,
+                                                  VAR_TEXTRUE_OFFSET);
         }
     }
 
@@ -81,8 +82,8 @@ protected void getVarsLocation() {
     public void delete() {
         super.delete();
 
-        hShadow = INVALID_HANDLE;
-        hMaskColor = INVALID_HANDLE;
-        hTexXOffset = INVALID_HANDLE;
+        mShadowLoc = INVALID_GL_HANDLE;
+        mMaskColorLoc = INVALID_GL_HANDLE;
+        mTexXOffsetLoc = INVALID_GL_HANDLE;
     }
 }

PageFlip/src/main/java/com/eschao/android/widget/pageflip/FoldBackVertexProgram.java

@@ -50,55 +50,38 @@ public FoldBackVertexes() {
      * Set vertex buffer with given mesh count
      *
      * @param meshCount mesh count
-     * @return self
      */
-    public FoldBackVertexes set(int meshCount) {
+    public void set(int meshCount) {
         super.set(meshCount << 1, 4, true);
         mNext = 0;
-        return this;
     }
 
     /**
      * Set mask alpha
      *
      * @param alpha mask alpha, value is [0 .. 255]
-     * @return self
      */
-    public FoldBackVertexes setMaskAlpha(int alpha) {
+    public void setMaskAlpha(int alpha) {
         if (alpha < 0 || alpha > 255) {
-            throw new IllegalArgumentException("Alpha: " + alpha + "is out of " +
-                                               "[0 .. 255]!");
+            throw new IllegalArgumentException("Alpha: " + alpha + "is out of "
+                                               + "[0 .. 255]!");
         }
 
         mMaskAlpha = alpha / 255.0f;
-        return this;
     }
 
     /**
      * set mask alpha
      *
      * @param alpha mask alpha, value is [0 .. 1]
-     * @return self
      */
-    public FoldBackVertexes setMaskAlpha(float alpha) {
+    public void setMaskAlpha(float alpha) {
         if (alpha < 0 || alpha > 1) {
-            throw new IllegalArgumentException("Alpha: " + alpha + "is out of " +
-                                               "[0 .. 1]!");
+            throw new IllegalArgumentException("Alpha: " + alpha + "is out of "
+                                               + "[0 .. 1]!");
         }
 
         mMaskAlpha = alpha;
-        return this;
-    }
-
-    /**
-     * Put all data from float array to float buffer
-     *
-     * @return self
-     */
-    public FoldBackVertexes toFloatBuffer() {
-        // fix coordinate x of texture for shadow of fold back
-        super.toFloatBuffer();
-        return this;
     }
 
     /**
@@ -113,37 +96,37 @@ public void draw(FoldBackVertexProgram program,
                      Page page,
                      boolean hasSecondPage,
                      int gradientShadowId) {
-        glUniformMatrix4fv(program.hMVPMatrix, 1, false,
+        glUniformMatrix4fv(program.mMVPMatrixLoc, 1, false,
                            VertexProgram.MVPMatrix, 0);
 
         // load fold back texture
         glBindTexture(GL_TEXTURE_2D, page.getBackTextureID());
-        glUniform1i(program.hTexture, 0);
+        glUniform1i(program.mTextureLoc, 0);
 
         // load gradient shadow texture
         glActiveTexture(GLES20.GL_TEXTURE1);
         glBindTexture(GL_TEXTURE_2D, gradientShadowId);
-        glUniform1i(program.hShadow, 1);
+        glUniform1i(program.mShadowLoc, 1);
 
         // set x offset of texture coordinate. In single page mode, the value is
         // set 0 to draw the back texture with x coordinate inversely against
         // the first texture since they are using the same texture, but in
         // double page mode, the back texture is different with the first one,
         // it is the next page content texture and should be drawn in the same
-        // order with the first texture, so the value is set 1. Computing
+        // order with the first texture, so the value is set 1. For computing
         // details, please see the shader script.
-        glUniform1f(program.hTexXOffset, hasSecondPage ? 1.0f : 0);
+        glUniform1f(program.mTexXOffsetLoc, hasSecondPage ? 1.0f : 0);
 
         // set mask color and alpha
-        glUniform4f(program.hMaskColor,
+        glUniform4f(program.mMaskColorLoc,
                     page.maskColor[0][0],
                     page.maskColor[0][1],
                     page.maskColor[0][2],
                     hasSecondPage ? 0 : mMaskAlpha);
 
         // draw triangles
         drawWith(GL_TRIANGLE_STRIP,
-                 program.hVertexPosition,
-                 program.hTextureCoord);
+                 program.mVertexPosLoc,
+                 program.mTexCoordLoc);
     }
 }

PageFlip/src/main/java/com/eschao/android/widget/pageflip/FoldBackVertexes.java

@@ -16,23 +16,23 @@
 package com.eschao.android.widget.pageflip;
 
 /**
- * GPoint includes (x,y,z) in OpenGL coordinate system and its texture
- * coordinates (tX, tY)
+ * GLPoint includes (x,y,z) in OpenGL coordinate system and its texture
+ * coordinates (texX, texY)
  *
  * @author eschao
  */
-public final class GPoint {
+public final class GLPoint {
     // 3D coordinate
     float x;
     float y;
     float z;
 
     // texutre coordinate
-    float tX;
-    float tY;
+    float texX;
+    float texY;
 
     /**
-     * Set GPoint with given values
+     * Set GLPoint with given values
      *
      * @param x x coordinate
      * @param y y coordinate
@@ -44,7 +44,7 @@ public void set(float x, float y, float z, float tX, float tY) {
         this.x = x;
         this.y = y;
         this.z = z;
-        this.tX = tX;
-        this.tY = tY;
+        this.texX = tX;
+        this.texY = tY;
     }
 }

PageFlip/src/main/java/com/eschao/android/widget/pageflip/GPoint.java renamed to PageFlip/src/main/java/com/eschao/android/widget/pageflip/GLPoint.java

@@ -35,11 +35,11 @@
 
 public class GLProgram {
 
-    // invalid handle
-    protected final int INVALID_HANDLE = -1;
+    // invalid GL getShaderRef including program reference and variable location
+    protected final int INVALID_GL_HANDLE = -1;
 
-    // GLSL program handle
-    protected int hProgram;
+    // GLSL program reference
+    protected int mProgramRef;
 
     // Vertex shader
     protected GLShader mVertex;
@@ -48,7 +48,7 @@ public class GLProgram {
     protected GLShader mFragment;
 
     public GLProgram() {
-        hProgram = INVALID_HANDLE;
+        mProgramRef = INVALID_GL_HANDLE;
         mVertex = new GLShader();
         mFragment = new GLShader();
     }
@@ -76,21 +76,21 @@ public GLProgram init(Context context, int vertexResId, int fragmentResId)
         }
 
         // 2. create texture program and link shader
-        hProgram = glCreateProgram();
-        if (hProgram == 0) {
+        mProgramRef = glCreateProgram();
+        if (mProgramRef == 0) {
             mVertex.delete();
             mFragment.delete();
             throw new PageFlipException("Can't create texture program");
         }
 
         // 3. attach vertex and fragment shader
-        glAttachShader(hProgram, mVertex.handle());
-        glAttachShader(hProgram, mFragment.handle());
-        glLinkProgram(hProgram);
+        glAttachShader(mProgramRef, mVertex.getShaderRef());
+        glAttachShader(mProgramRef, mFragment.getShaderRef());
+        glLinkProgram(mProgramRef);
 
         // 4. check shader link status
         int[] result = new int[1];
-        glGetProgramiv(hProgram, GL_LINK_STATUS, result, 0);
+        glGetProgramiv(mProgramRef, GL_LINK_STATUS, result, 0);
         if (result[0] == 0) {
             delete();
             throw new PageFlipException("Can't link program");
@@ -99,7 +99,7 @@ public GLProgram init(Context context, int vertexResId, int fragmentResId)
         // 5. get all variable handles defined in scripts
         // subclass should implement getVarsLocation to be responsible for its
         // own variables in script
-        glUseProgram(hProgram);
+        glUseProgram(mProgramRef);
         getVarsLocation();
         return this;
     }
@@ -111,19 +111,19 @@ public void delete() {
         mVertex.delete();
         mFragment.delete();
 
-        if (hProgram != INVALID_HANDLE) {
-            glDeleteProgram(hProgram);
-            hProgram = INVALID_HANDLE;
+        if (mProgramRef != INVALID_GL_HANDLE) {
+            glDeleteProgram(mProgramRef);
+            mProgramRef = INVALID_GL_HANDLE;
         }
     }
 
     /**
-     * Get program handle
+     * Get program GL reference
      *
-     * @return program handle
+     * @return program GL reference for program
      */
-    public int handle() {
-        return hProgram;
+    public int getProgramRef() {
+        return mProgramRef;
     }
 
     /**

PageFlip/src/main/java/com/eschao/android/widget/pageflip/GLProgram.java

@@ -40,15 +40,16 @@
 public class GLShader {
 
     private final static String TAG = "GLShader";
+    private final int INVALID_GL_HANDLE = -1;
 
-    // shader handle
-    int hShader;
+    // shader object reference
+    int mShaderRef;
 
     /**
      * Default constructor
      */
     public GLShader() {
-        hShader = 0;
+        mShaderRef = INVALID_GL_HANDLE;
     }
 
     /**
@@ -70,24 +71,24 @@ public GLShader compile(Context context, int type, int resId)
         }
 
         // create a shader
-        hShader = glCreateShader(type);
-        if (hShader != 0) {
+        mShaderRef = glCreateShader(type);
+        if (mShaderRef != INVALID_GL_HANDLE) {
             // upload shader scripts to GL
-            glShaderSource(hShader, codes);
+            glShaderSource(mShaderRef, codes);
 
             // compile shader scripts
-            glCompileShader(hShader);
+            glCompileShader(mShaderRef);
 
             // get compile results to check if it is successful
             final int[] result = new int[1];
-            glGetShaderiv(hShader, GL_COMPILE_STATUS, result, 0);
+            glGetShaderiv(mShaderRef, GL_COMPILE_STATUS, result, 0);
             if (result[0] == 0) {
                 // delete shader if compile is failed
                 Log.e(TAG, "Can'top compile shader for type: " + type +
                            "Error: " + glGetError());
                 Log.e(TAG, "Compile shader error: " +
-                           glGetShaderInfoLog(hShader));
-                glDeleteShader(hShader);
+                           glGetShaderInfoLog(mShaderRef));
+                glDeleteShader(mShaderRef);
                 throw new PageFlipException("Can't compile shader for" +
                                             "type: " + type);
             }
@@ -103,19 +104,19 @@ public GLShader compile(Context context, int type, int resId)
      * Delete shader
      */
     public void delete() {
-        if (hShader != 0) {
-            glDeleteShader(hShader);
-            hShader = 0;
+        if (mShaderRef != INVALID_GL_HANDLE) {
+            glDeleteShader(mShaderRef);
+            mShaderRef = INVALID_GL_HANDLE;
         }
     }
 
     /**
-     * Get shader handle
+     * Get shader object reference
      *
-     * @return shader handle
+     * @return shader object reference in OpenGL
      */
-    public int handle() {
-        return hShader;
+    public int getShaderRef() {
+        return mShaderRef;
     }
 
     /**