Question

我正在尝试更改我的opengl视图中对象上显示的纹理图像，以响应按钮单击。目前，当用户按下按钮时，我在我的OpenGL渲染器线程中将标志设置为true。我的跨线程通信似乎很好：我能够成功地在Renderer线程中切换标志变量。我的问题似乎是Open GL onDraw（）工作流程，我无法弄清楚如何在渲染器的初始onSurfaceCreated（）执行期间设置纹理之后系统地更改对象上的纹理。

似乎fretBoardTexture = new OpenGL_TextureData（mActivityContext，R.drawable.dark_wood）;永远不会在onSurfaceCreated（）之外工作，为什么？

以下是我尝试过的代码。我在某处错过了一系列GLES20（）方法调用吗？

OpenGL渲染器类

 private int chosenWoodColor = 1;

        public void onSurfaceCreated(GL10 glUnused, EGLConfig config) {
            ...
            loadFretBoardTexture();  //this call works: it succeeds in changing texture
        }

        public void onDrawFrame(GL10 glUnused) {
                if (flag){    
                    loadFretBoardTexture(); //this call fails: it never changes the texture
                }
                ...

                //***Fretboard OpenGL_TextureData Binding***
                GLES20.glActiveTexture(GLES20.GL_TEXTURE1);

                // Bind the texture to this unit.
                GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, fretBoard._textureID);

                //Draw Background
                Matrix.setIdentityM(mModelMatrix, 0);
                Matrix.translateM(mModelMatrix, 0, 0.0f, 0.0f, -1.0f);
                drawFretBoard(); //draw the fretboard
                ...
        }

        public void loadFretBoardTexture(){
                switch (chosenWoodColor){
                    case 1:
                        fretBoardTexture = new OpenGL_TextureData(mActivityContext, R.drawable.dark_wood);
                        break;
                    case 2:
                        fretBoardTexture = new OpenGL_TextureData(mActivityContext, R.drawable.medium_wood);
                        break;
                    case 3:
                        fretBoardTexture = new OpenGL_TextureData(mActivityContext, R.drawable.light_wood);
                        break;
                }
                setFretboardTextureRefresh(false);
                return;
            }

纹理数据助手类

public class OpenGL_TextureData {
    public int textureID;
    public float imageWidth, imageHeight;

    public OpenGL_TextureData(Context context, int resourceId) { //constructor
        final int[] textureHandle = new int[1];

        GLES20.glGenTextures(1, textureHandle, 0);

        if (textureHandle[0] != 0) {
            final BitmapFactory.Options options = new BitmapFactory.Options();
            options.inScaled = false;   // No pre-scaling

            // Read in the resource
            final Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), resourceId, options);

            //fetch texture image width & height
            imageWidth = options.outWidth;
            imageHeight = options.outHeight;

            // Bind to the texture in OpenGL
            GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureHandle[0]);

            // Set filtering
            GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S, GLES20.GL_REPEAT);
            GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T, GLES20.GL_REPEAT);
            GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER, GLES20.GL_LINEAR);
            GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_LINEAR);

            // Load the bitmap into the bound texture.
            GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);

            // Recycle the bitmap, since its data has been loaded into OpenGL.
            bitmap.recycle();
        }

        if (textureHandle[0] == 0) {
            throw new RuntimeException("Error loading texture.");
        }

        textureID = textureHandle[0];
    }
}

Answer 1

解决。

问题是我正在创建一个新的纹理对象并为其加载一个位图，但由于纹理对象已经在我的onSurfaceCreated（）方法中创建，这是不可取的：我真的只需要将一个位图加载到已经现有的纹理对象。

我在Texture数据助手类中添加了以下方法：

public void updateTexture(Context context, int resourceId) {
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inScaled = false;   // No pre-scaling
        final Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), resourceId, options);  //Read in the resource
        GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, 1);
        // Load the bitmap into the bound texture.
        GLUtils.texImage2D(GLES20.GL_TEXTURE_2D, 0, bitmap, 0);
        bitmap.recycle();
    }

来自here

的灵感

Android：如何动态更改OpenGL ES纹理图像

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