Texturing and Shading - Learn OpenGL ES: For Mobile Game and Graphics Development - page 184

the ShortBuffer (corresponding to the element array buffer object ), if you as-
signed it as the current buffer object, as shown in Listing 5-2 . So, in place of
FloatBuffer or ShortBuffer , argument “0” is passed when calling glVer-
texAttribPointer or glDrawElements .
Listing 5-2. TANK FENCE 1/src/com/apress/android/tankfence1/GLES20Ren-
derer.java
GLES20.glUseProgram(_tankProgram);
GLES20.glUniformMatrix4fv(_tankUMVPLocation, 1, false,
_MVPMatrix, 0);
GLES20.glBindBuffer(GLES20.GL_ARRAY_BUFFER,
_tankBuffers[0]);
GLES20.glVertexAttribPointer(_tankAPositionLocation,
3, GLES20.GL_FLOAT, false, 12, 0);
GLES20.glEnableVertexAttribArray(_tankAPositionLocation);
GLES20.glBindBuffer(GLES20.GL_ELEMENT_ARRAY_BUFFER,
_tankBuffers[1]);
GLES20.glDrawElements(GLES20.GL_TRIANGLES, 84,
GLES20.GL_UNSIGNED_SHORT, 0);
To understand this better, import the archive file Chapter5/tankfence1.zip .
This loads the TANK FENCE 1 application into your Eclipse workspace. You will
also find other similar applications in the source code - TANK FENCE 2 and TANK
FENCE 3 . These three applications will help you move in a stepwise manner to
use buffer objects for the plane, enemy, and player (game objects in the Tank
Fence game). The outputs of these applications are similar to the TANK FENCE
ELEMENTS * series of applications. The only difference between these applications
is the use of buffer objects.
Using Color Masks
Before moving further, I will also talk about using color masks in ES 2.0. Color
masks allow you to enable or disable writes to specific components (red, green, blue,
and alpha) in the color buffer.