I am beginner in openGL. i am created a prism ( each face is equilateral triangle ) in android using openGL library and i am able to rotate the prism successfully. but my requirment is to put three different images in each face of the prism and i am not able to put the images. when i am putting the image it is scaling and mapping to all faces.
MyRenderer Class
public class MyRenderer implements Renderer {
/** Cube instance */
/* Rotation values for all axis */
private float xrot; //X Rotation ( NEW )
private float yrot; //Y Rotation ( NEW )
private float zrot; //Z Rotation ( NEW )
/** The Activity Context ( NEW ) */
private Context context;
private Pyramid pyramid;
/**
* Instance the Cube object and set
* the Activity Context handed over
*/
public MyRenderer(Context context) {
this.context = context;
pyramid = new Pyramid(this.context);
}
/**
* The Surface is created/init()
*/
public void onSurfaceCreated(GL10 gl, EGLConfig config) {
//Load the texture for the cube once during Surface creation
gl.glEnable(GL10.GL_TEXTURE_2D); //Enable Texture Mapping ( NEW )
gl.glShadeModel(GL10.GL_SMOOTH); //Enable Smooth Shading
gl.glClearColor(1.0f, 1.0f, 1.0f, 0.5f); //Black Background
gl.glClearDepthf(1.0f); //Depth Buffer Setup
gl.glEnable(GL10.GL_DEPTH_TEST); //Enables Depth Testing
gl.glDepthFunc(GL10.GL_LEQUAL); //The Type Of Depth Testing To Do
//Really Nice Perspective Calculations
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
}
/**
* Here we do our drawing
*/
public void onDrawFrame(GL10 gl) {
//Clear Screen And Depth Buffer
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glLoadIdentity(); //Reset The Current Modelview Matrix
//Drawing
gl.glTranslatef(0.0f, -1.0f, -5.0f); //Move 5 units into the screen
gl.glScalef(1.0f, 1.0f, 1.0f); //Scale the Cube to 80 percent, otherwise it would be too large for the screen
//Rotate around the axis based on the rotation matrix (rotation, x, y, z)
gl.glRotatef(yrot, 0.0f, 1.65f, 0.0f); //X
pyramid.draw(gl, context);
yrot += 1.0f;
}
/**
* If the surface changes, reset the view
*/
public void onSurfaceChanged(GL10 gl, int width, int height) {
if(height == 0) { //Prevent A Divide By Zero By
height = 1; //Making Height Equal One
}
gl.glViewport(0, 0, width, height); //Reset The Current Viewport
gl.glMatrixMode(GL10.GL_PROJECTION); //Select The Projection Matrix
gl.glLoadIdentity(); //Reset The Projection Matrix
//Calculate The Aspect Ratio Of The Window
GLU.gluPerspective(gl, 45.0f, (float)width / (float)height, 0.1f, 100.0f);
gl.glMatrixMode(GL10.GL_MODELVIEW); //Select The Modelview Matrix
gl.glLoadIdentity(); //Reset The Modelview Matrix
}
}
MyPyramid class
public class Pyramid {
/** The buffer holding the vertices */
private FloatBuffer vertexBuffer;
/** The buffer holding the color values */
private FloatBuffer colorBuffer;
private ByteBuffer indexBuffer;
private FloatBuffer textureBuffer;
private int noOfFaces = 3;
private int[] texturesID = new int[3];
private float PyramidVertices [] = {
0.0f, 1.65f, 0.0f,
-1.3f, 0.0f, 1.0f,
1.3f, 0.0f, 1.0f,
0.0f, 0.0f, -1.65f,
};
private float textures[] = {
//Mapping coordinates for the vertices
0.0f, 1.65f,
0.0f, 1.65f,
-1.3f, 0.0f,
1.3f, 0.0f,
};
private float colors[] = {
1.0f, 0.0f, 0.0f, 1.0f, //Red
0.0f, 1.0f, 0.0f, 1.0f, //Green
0.0f, 0.0f, 1.0f, 1.0f, //Blue
1.0f, 0.0f, 0.0f, 1.0f, //Red
};
private byte indices [] = { 0, 2, 1,
0, 2, 3,
0, 1, 3,
};
/**
* The Pyramid constructor.
*
* Initiate the buffers.
*/
public Pyramid( Context context) {
//
ByteBuffer byteBuf = ByteBuffer.allocateDirect(PyramidVertices.length * 4);
byteBuf.order(ByteOrder.nativeOrder());
vertexBuffer = byteBuf.asFloatBuffer();
vertexBuffer.put(PyramidVertices);
vertexBuffer.position(0);
byteBuf = ByteBuffer.allocateDirect(colors.length * 4);
byteBuf.order(ByteOrder.nativeOrder());
colorBuffer = byteBuf.asFloatBuffer();
colorBuffer.put(colors);
colorBuffer.position(0);
indexBuffer = ByteBuffer.allocateDirect(indices.length);
indexBuffer.put(indices);
indexBuffer.position(0);
byteBuf = ByteBuffer.allocateDirect(textures.length * 4);
byteBuf.order(ByteOrder.nativeOrder());
textureBuffer = byteBuf.asFloatBuffer();
textureBuffer.put(textures);
textureBuffer.position(0);
}
/**
* The object own drawing function.
* Called from the renderer to redraw this instance
* with possible changes in values.
*
* @param gl - The GL Context
*/
public void draw(GL10 gl, Context context) {
//Set the face rotation
// gl.glFrontFace(GL10.GL_CW);
gl.glCullFace(GL10.GL_CCW);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
// gl.glColorPointer(4, GL10.GL_FLOAT, 0, colorBuffer);
loadTexture(gl, context);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);
gl.glEnable(GL10.GL_TEXTURE_2D);
// Enable the texture state
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
// Point to our buffers
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glDrawElements(GL10.GL_TRIANGLES, indices.length, GL10.GL_UNSIGNED_BYTE, indexBuffer);
//Disable the client state before leaving
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
}
public void loadTexture(GL10 gl, Context context) {
Bitmap bitmap;
gl.glGenTextures(3, texturesID, 0); // Generate texture-ID array for 6 IDs
gl.glBindTexture(GL10.GL_TEXTURE_2D, texturesID[2]);
InputStream is = context.getResources().openRawResource(R.drawable.forward);
try {
//BitmapFactory is an Android graphics utility for images
bitmap = BitmapFactory.decodeStream(is);
} finally {
//Always clear and close
try {
is.close();
is = null;
} catch (IOException e) {
}
}
// Generate OpenGL texture images
// Create Nearest Filtered Texture
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER,
GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER,
GL10.GL_LINEAR);
// Different possible texture parameters, e.g. GL10.GL_CLAMP_TO_EDGE
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S,
GL10.GL_CLAMP_TO_EDGE);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T,
GL10.GL_REPEAT);
// Build Texture from loaded bitmap for the currently-bind texture ID
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
}
and i took the help from http://www3.ntu.edu.sg/home/ehchua/programming/android/Android_3D.html http://nehe.gamedev.net/
How to give different images on each face?
