make Texture using OpenGL - Android android.opengl

Android examples for android.opengl:OpenGL Texture

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Description

make Texture using OpenGL

Demo Code


//package com.java2s;
import android.graphics.Bitmap;
import static android.opengl.GLES20.*;
import java.nio.ByteBuffer;
import java.nio.IntBuffer;
import android.opengl.GLUtils;

public class Main {
    public static int makeTexture(int x, int y, int color) {
        int[] tid = new int[1];
        ByteBuffer bb = ByteBuffer.allocateDirect(x * y * 4);
        IntBuffer ib = bb.asIntBuffer();

        //int color = 0x0000ffff;
        for (int i = 0; i < x * y; i++) {
            ib.put(color);/*from   w ww  .  j a  va 2 s.  c o  m*/
        }

        // Create and bind a single texture object.
        glGenTextures(1, tid, 0);
        glBindTexture(GL_TEXTURE_2D, tid[0]);

        // Copy the texture to the GPU
        glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, x, y, 0, GL_RGBA,
                GL_UNSIGNED_BYTE, bb);

        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
        glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);

        // Unbind texture
        glBindTexture(GL_TEXTURE_2D, 0);

        return tid[0];
    }

    public static int makeTexture(Bitmap bitmap, int w, int h) {
        int textureId = makeTexture(w, h, 0xffffffff);
        if (bitmap != null) {
            Bitmap flippedbmp = flipBitmap(bitmap);
            glBindTexture(GL_TEXTURE_2D, textureId);
            GLUtils.texSubImage2D(GL_TEXTURE_2D, 0, 0, 0, flippedbmp);
            glBindTexture(GL_TEXTURE_2D, 0);
        }
        return textureId;
    }

    /** Flips the pixels in a Bitmap to be mirrored vertically.  This is needed
     * for OpenGL to draw the texture properly as loads texture bottom up.
     * @return a new Bitmap that is identical to the argument but flipped.
     * @param bitmap The Bitmap to flip the pixels of
     */
    static public Bitmap flipBitmap(Bitmap bitmap) {
        int w = bitmap.getWidth();
        int h = bitmap.getHeight();
        int[] pixels = new int[w * h];
        bitmap.getPixels(pixels, 0, w, 0, 0, w, h);
        for (int y = 0; y < h; y++) {
            for (int x = 0; x < w; x++) {
                pixels[y * w + x] = bitmap.getPixel(x, h - 1 - y);
            }
        }
        bitmap = Bitmap.createBitmap(pixels, w, h, Bitmap.Config.ARGB_8888);
        return bitmap;
    }
}

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