Java implementation of OpenGL ES texture mapping method _java

In this paper, we illustrate the method of implementing OpenGL ES texture mapping in java. Share to everyone for your reference. Specifically as follows:

1. Glrenderer.java Documents:

Package Net.obviam.opengl;
Import Javax.microedition.khronos.egl.EGLConfig;
Import javax.microedition.khronos.opengles.GL10;
Import Android.content.Context;
Import Android.opengl.GLU;
Import Android.opengl.GLSurfaceView.Renderer;   public class Glrenderer implements Renderer {private square square;
  The square private context;
    /** constructor to set of the handed over context * * Public glrenderer (Context context) {This.context = context;
  Initialise the square this.square = new Square (); @Override public void Ondrawframe (GL10 gl) {//clear screen and Depth Buffer gl.glclear (Gl10.gl_color_buffe R_bit |
    Gl10.gl_depth_buffer_bit);
    Reset the Modelview Matrix gl.glloadidentity ();
    Drawing Gl.gltranslatef (0.0f, 0.0f, -5.0f);
Move 5 units to the screen/are the same as moving the camera 5 units away//Gl.glscalef (0.5f, 0.5f, 0.5f); Scale the square to 50%//otherwise it'll be too large square.Draw (GL); Draw the triangle} @Override 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) Widt
    H/(float) height, 0.1f, 100.0f);
    Gl.glmatrixmode (Gl10.gl_modelview); Select the Modelview Matrix gl.glloadidentity (); Reset the Modelview Matrix} @Override public void onsurfacecreated (GL10 gl, eglconfig config) {//Load the T
    Exture for the square square.loadgltexture (GL, this.context); Gl.glenable (gl10.gl_texture_2d); Enable Texture Mapping (NEW) Gl.glshademodel (Gl10.gl_smooth); Enable Smooth Shading Gl.glclearcolor (0.0f, 0.0f, 0.0f, 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 does//really nice perspective calculations Gl.glhint (gl10.gl_perspective_correction_ 
  HINT, gl10.gl_nicest);

 }
}

2. Square.java File:

Package Net.obviam.opengl;
Import Java.nio.ByteBuffer;
Import Java.nio.ByteOrder;
Import Java.nio.FloatBuffer;
Import javax.microedition.khronos.opengles.GL10;
Import Android.content.Context;
Import Android.graphics.Bitmap;
Import Android.graphics.BitmapFactory;
Import Android.opengl.GLUtils;  public class Square {private Floatbuffer vertexbuffer; Buffer holding the vertices private float vertices[] = { -1.0f, -1.0f, 0.0f,//V1-bottom left-1.0f , 1.0f, 0.0f,//V2-top left 1.0f, -1.0f, 0.0f,//V3-bottom right 1.0f, 1.0f, 0.0f//V4-to
  P Right}; Private Floatbuffer Texturebuffer; 
      Buffer holding the texture coordinates private float texture[] = {//Mapping coordinates for the vertices
      0.0f, 1.0f,//Top Left (V2) 0.0f, 0.0f,//Bottom Left (V1) 1.0f, 1.0f,//Top Right (V4)
  1.0f, 0.0f//Bottom Right (V3)}; /** the texture pointer * * Private int[] textures = new Int[1]; Public Square () {//a float has 4 bytes so we allocate for each coordinate 4 bytes bytebuffer Bytebuffer = Bytebu
    Ffer.allocatedirect (Vertices.length * 4);
    Bytebuffer.order (Byteorder.nativeorder ());
    Allocates the memory from the byte buffer vertexbuffer = Bytebuffer.asfloatbuffer ();
    Fill the vertexbuffer with the vertices vertexbuffer.put (vertices);
    Set the cursor position to the beginning of the buffer vertexbuffer.position (0);
    Bytebuffer = Bytebuffer.allocatedirect (Texture.length * 4);
    Bytebuffer.order (Byteorder.nativeorder ());
    Texturebuffer = Bytebuffer.asfloatbuffer ();
    Texturebuffer.put (texture);
  Texturebuffer.position (0);  /** * Load The texture for the "square * @param GL * @param context */public void Loadgltexture (GL10 gl, Context context) {//loading texture Bitmap Bitmap = Bitmapfactory.decoderesource (Context.getresources (), R.draw
    Able.android); Generate one texture pointer
    Gl.glgentextures (1, textures, 0);
    ... and bind it to our array gl.glbindtexture (gl10.gl_texture_2d, textures[0]); Create nearest filtered texture Gl.gltexparameterf (gl10.gl_texture_2d, Gl10.gl_texture_min_filter, GL10.GL_NEAREST
    );
    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_repeat);
    Gl.gltexparameterf (gl10.gl_texture_2d, gl10.gl_texture_wrap_t, gl10.gl_repeat); Use the Android glutils to specify a two-dimensional texture image from our bitmap glutils.teximage2d (gl10.gl_texture_
    2d, 0, bitmap, 0);
  Clean up bitmap.recycle (); }/** The draw method for the "square with" GL Context */public void Draw (GL10 GL) {//Bind the previously Gen
    erated Texture Gl.glbindtexture (gl10.gl_texture_2d, textures[0]); Point to our buffers GL.GLenableclientstate (Gl10.gl_vertex_array);
    Gl.glenableclientstate (Gl10.gl_texture_coord_array);
    Set The face rotation gl.glfrontface (GL10.GL_CW);
    Point to our vertex buffer Gl.glvertexpointer (3, gl10.gl_float, 0, VertexBuffer);
    Gl.gltexcoordpointer (2, gl10.gl_float, 0, Texturebuffer);
    Draw the vertices as Triangle strip gl.gldrawarrays (Gl10.gl_triangle_strip, 0, VERTICES.LENGTH/3);
    Disable the client state before leaving Gl.gldisableclientstate (Gl10.gl_vertex_array);
  Gl.gldisableclientstate (Gl10.gl_texture_coord_array);

 }
}

3. Triangle.java File:

Package Net.obviam.opengl;
Import Java.nio.ByteBuffer;
Import Java.nio.ByteOrder;
Import Java.nio.FloatBuffer;
Import javax.microedition.khronos.opengles.GL10;  public class Triangle {private Floatbuffer vertexbuffer;
       Buffer holding the vertices private float vertices[] = { -0.5f, -0.5f, 0.0f,//V1-first vertex (x,y,z)      0.5f, -0.5f, 0.0f,//V2-second vertex 0.0f, 0.5f, 0.0f//v3-third vertex//1.0f, 0.5f, 0.0f
  V3-third vertex}; Public triangle () {//a float has 4 bytes so we allocate for each coordinate 4 bytes Bytebuffer Vertexbytebuffer
    = Bytebuffer.allocatedirect (Vertices.length * 4);
    Vertexbytebuffer.order (Byteorder.nativeorder ());
    Allocates the memory from the byte buffer vertexbuffer = Vertexbytebuffer.asfloatbuffer ();
    Fill the vertexbuffer with the vertices vertexbuffer.put (vertices);
  Set the cursor position to the beginning of the buffer vertexbuffer.position (0); }
  /** the draw method for the triangle and the GL context * * public void Draw (GL10 gl) {gl.glenableclientstate (GL
    10.gl_vertex_array);
    Set the colour for the background//Gl.glclearcolor (0.0f, 0.0f, 0.0f, 0.5f);
    To show the color [paint the screen] we need to clear the color buffer//gl.glclear (gl10.gl_color_buffer_bit);
    Set the colour for the Triangle gl.glcolor4f (0.0f, 1.0f, 0.0f, 0.5f);
    Point to our vertex buffer Gl.glvertexpointer (3, gl10.gl_float, 0, VertexBuffer);
    Draw the vertices as Triangle strip gl.gldrawarrays (Gl10.gl_triangle_strip, 0, VERTICES.LENGTH/3);
  Disable the client state before leaving Gl.gldisableclientstate (Gl10.gl_vertex_array);

 }
}

4. Run.java File:

Package Net.obviam.opengl;
Import android.app.Activity;
Import Android.opengl.GLSurfaceView;
Import Android.os.Bundle;
Import Android.view.Window;
Import Android.view.WindowManager;
  public class Run extends activity {/** The OpenGL view/private Glsurfaceview Glsurfaceview; /** called the activity is a.
    * * @Override public void onCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate);
    Requesting to turn the title off Requestwindowfeature (Window.feature_no_title); Making it full screen GetWindow (). SetFlags (WindowManager.LayoutParams.FLAG_FULLSCREEN, Windowmanager.layout
    Params.flag_fullscreen); 
    Initiate the "Open GL View and//create an instance with the" Glsurfaceview = new Glsurfaceview (this); Set our renderer to is the main renderer with//the current Activity context glsurfaceview.setrenderer (NE
    W Glrenderer (this));
  Setcontentview (Glsurfaceview); }
  /**
   *Remember to resume the glsurface * * * @Override protected void Onresume () {super.onresume ();
  Glsurfaceview.onresume ();
    }/** * Also pause the glsurface/@Override protected void OnPause () {super.onpause ();
  Glsurfaceview.onpause ();

 }
}

I hope this article will help you with your Java programming.