编辑 6 - 完全重写与评论/正在进行的研究有关
编辑 7 - 添加投影/视图矩阵.....
由于我对此还没有走多远，因此我从 Google 演示中添加了视图/投影矩阵 - 请参见下面的代码：如果有人能指出我哪里出错了，我将不胜感激，因为我仍然得到一个当我将 ""gl_position = a_position * uMVPMatrix;" + 放入我的顶点着色器时出现空白屏幕（使用 "gl_position = a_position;" + 我的四边形至少显示......）
在班级级别声明：（四班）
private final float[] rotationMat = new float[16];
private FloatBuffer flotRotBuf;
ByteBuffer rotBuf;
private int muRotationHandle = -1; // Handle to the rotation matrix in the vertex shader called "uRotate"
在类杠杆上声明：（渲染器类）
private final float[] mVMatrix = new float[16];
private final float[] mProjMatrix = new float[16];
private final float[] mMVPMatrix = new float[16];
设置纹理并执行（或应该执行）旋转的例程（这是在我的 Quad 类中
public void setTexture(GLSurfaceView view, Bitmap imgTexture, float[] mvpMatrix){
this.imgTexture=imgTexture;
// get handle to shape's transformation matrix
mMVPMatrixHandle = GLES20.glGetUniformLocation(iProgId, "uMVPMatrix");
// Apply the projection and view transformation
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0);
// Matrix.setRotateM(rotationMat, 0, 45f, 0, 0, 1.0f); //Set rotation matrix with angle and (z) axis
// rotBuf = ByteBuffer.allocateDirect(rotationMat.length * 4);
// use the device hardware's native byte order
// rotBuf.order(ByteOrder.nativeOrder());
// create a floating point buffer from the ByteBuffer
// flotRotBuf = rotBuf.asFloatBuffer();
// add the coordinates to the FloatBuffer
// flotRotBuf.put(rotationMat);
// set the buffer to read the first coordinate
// flotRotBuf.position(0);
// muRotationHandle = GLES20.glGetUniformLocation(iProgId, "uRotation"); // grab the variable from the shader
// GLES20.glUniformMatrix4fv(muRotationHandle, 1, false, flotRotBuf); //Pass floatbuffer contraining rotation matrix info into vertex shader
//GLES20.glUniformMatrix4fv(muRotationHandle, 1, false, rotationMat, 1); //Also tried this ,not use floatbuffer
//Vertex shader
String strVShader =
// "uniform mat4 uRotation;" +
"uniform mat4 uMVPMatrix;" +
"attribute vec4 a_position;\n"+
"attribute vec2 a_texCoords;" +
"varying vec2 v_texCoords;" +
"void main()\n" +
"{\n" +
"gl_Position = a_Position * uMVPMatrix;"+ //This is where it all goes wrong....
"v_texCoords = a_texCoords;" +
"}";
//Fragment shader
String strFShader =
"precision mediump float;" +
"varying vec2 v_texCoords;" +
"uniform sampler2D u_baseMap;" +
"void main()" +
"{" +
"gl_FragColor = texture2D(u_baseMap, v_texCoords);" +
"}";
iProgId = Utils.LoadProgram(strVShader, strFShader);
iBaseMap = GLES20.glGetUniformLocation(iProgId, "u_baseMap");
iPosition = GLES20.glGetAttribLocation(iProgId, "a_position");
iTexCoords = GLES20.glGetAttribLocation(iProgId, "a_texCoords");
texID = Utils.LoadTexture(view, imgTexture);
}
从我的渲染器类：
public void onSurfaceChanged(GL10 gl, int width, int height) {
// TODO Auto-generated method stub
//Set viewport size based on screen dimensions
GLES20.glViewport(0, 0, width, height);
float ratio = (float) width / height;
Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 3, 7);
}
public void onDrawFrame(GL10 gl) {
// TODO Auto-generated method stub
//Paint the screen the colour defined in onSurfaceCreated
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
// Set the camera position (View matrix)
Matrix.setLookAtM(mVMatrix, 0, 0, 0, -3, 0f, 0f, 0f, 0f, 1.0f, 0.0f);
// Calculate the projection and view transformation
Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
quad1.setTexture(curView, myBitmap, mMVPMatrix); //SetTexture now modified to take a float array (See above) - Note I know it's not a good idea to have this in my onDrawFrame method - will move it once I have it working!
quad1.drawBackground();
}
我现在已经删除了所有与旋转相关的东西，现在只是尝试在顶点着色器中应用 uMVPMatrix 后显示一个静态四边形。但仍然没有:-(
如果我只是将该行更改回 'default' ：
"gl_Position = a_position;\n"+
然后我至少显示了我的纹理四边形（显然没有旋转，我希望如此）。
还要指出的是，mvpMatrix 肯定被完整地接收到 setTexture 方法中是有效的（包含与我从 Google 开发人员代码记录 mvpMatrix 的内容时出现的相同数据）。我不确定如何检查着色器是否完好无损地接收它？我没有理由相信它不是。
真的很感激和所有的帮助——我一定是在某个地方出错了，但我就是找不到。谢谢！
编辑 2：在为这个问题添加了赏金之后，我只想知道如何旋转我的纹理四边形精灵（2D），保持我必须将其渲染为基础的代码。（即，我需要添加什么才能旋转以及为什么）。谢谢！
编辑 3不适用
编辑 4重新措辞/简化的问题
编辑 5添加了错误截图
