我花了几天时间搜索，尝试教程，而不是真正得到结果，所以我在这里。
我正在尝试，简单地说，在屏幕上以2D格式动画一组对象（Android Studio），每个独立的移动和旋转。但是，当我尝试这个时，我要么没有渲染对象，要么渲染倾斜（就好像在垂直Y轴上旋转一样）
我知道绘制对象的顺序的重要性（给出正确的Z排序外观）但是，我对矩阵操作有点不知所措。
这是我到目前为止所做的：
主要活动 - 标准内容
private GLSurfaceView mGLSurfaceView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mGLSurfaceView = new GLSurfaceView(this);
//check if device supports ES 2.0
final ActivityManager activityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
final ConfigurationInfo configurationInfo = activityManager.getDeviceConfigurationInfo();
final boolean supportsEs2 = configurationInfo.reqGlEsVersion >= 0x20000;
if (supportsEs2) {
//Get the ES2 compatible context
mGLSurfaceView.setEGLContextClientVersion(2);
//set renderer to my renderer below
mGLSurfaceView.setRenderer(new MyGL20Renderer(this));
} else {
//no support
return;
}
//setContentView(R.layout.activity_main);
setContentView(mGLSurfaceView);
}
GL20Renderer类 - 请注意我现在只是手动将2个对象添加到我的集合中以进行渲染
public class MyGL20Renderer implements GLSurfaceView.Renderer
{
private final Context mActivityContext;
//Matrix Initializations
private final float[] mMVPMatrix = new float[16];
private final float[] mProjMatrix = new float[16];
private final float[] mVMatrix = new float[16];
private float[] mRotationMatrix = new float[16];
private final float[] mRotateMatrix = new float[16];
private final float[] mMoveMatrix = new float[16];
private final float[] mTempMatrix = new float[16];
private final float[] mModelMatrix = new float[16];
private int numObjects = 2;
private ArrayList<Sprite> spriteList = new ArrayList<Sprite>();
//Declare as volatile because we are updating it from another thread
public volatile float mAngle;
//private Triangle triangle;
//private Sprite sprite;
public MyGL20Renderer(final Context activityContext)
{
mActivityContext = activityContext;
}
public void onSurfaceCreated(GL10 unused, EGLConfig config)
{
//Set the background frame color
GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
//Set the camera position (View Matrix) //mtx, offset, eyex,y,z, centrex,y,z, upx,y,z
Matrix.setLookAtM(mVMatrix, 0,
0, 0, -1.5f, //Eye XYZ - position eye behind the origin
0f, 0f, -5.0f, //Look XYZ - We are looking toward the distance
0f, 1.0f, 0.0f); //Up XYZ - Up vector - where head would be pointing if holding the camera
//Initialize Shapes
//triangle = new Triangle();
//sprite = new Sprite(mActivityContext);
//Sprite newSprite;
float xMax = 2.0f;
float yMax = 2.0f;
//rand = 0->1
float newX = (new Random().nextFloat() * xMax * 2) - xMax; //2.0f; //-2 -> +2
float newY = (new Random().nextFloat() * yMax * 2) - yMax; //-3 -> +3
float newZ = 0f;
//for (int i=0; i<numObjects; i++) {
//newSprite = new Sprite(mActivityContext);
//spriteList.add(new Sprite(mActivityContext, newX, newY, newZ));
//}
spriteList.add(new Sprite(mActivityContext, -0.0f, -0.0f, 0.0f));
spriteList.add(new Sprite(mActivityContext, +0.5f, -0.5f, 0.0f));
//spriteList.add(new Sprite(mActivityContext, -1.0f, +1.0f, 0.0f));
//spriteList.add(new Sprite(mActivityContext, +1.0f, +1.0f, 0.0f));
}
public void onDrawFrame(GL10 unused)
{
//init
Sprite currSprite;
//Redraw background color
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
//timing
float jFactor = 0.1f;
long time = SystemClock.uptimeMillis() % 10000L;
float angleInDegrees = (360.0f / 1000.0f) * ((int) time) * jFactor;
/*
//number 1
//Matrix.setIdentityM(mModelMatrix, 0);
//currSprite = spriteList.get(0);
//Matrix.rotateM(mModelMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
//currSprite.Draw(mModelMatrix);
//number 2
Matrix.setIdentityM(mModelMatrix, 0);
currSprite = spriteList.get(1);
Matrix.translateM(mModelMatrix, 0, 0.0f, -0.1f, 0.0f);
//Matrix.rotateM(mModelMatrix, 0, 90.0f, 1.0f, 0.0f, 0.0f);
Matrix.rotateM(mModelMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
currSprite.Draw(mModelMatrix);
//Matrix.translateM(mModelMatrix, 0, 0, 0, 4.0f);
*/
//Calculate the projection and view transformation
Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
//zoom out a bit?
Matrix.translateM(mMVPMatrix, 0, 0, 0, 4.0f);
//number 1
//currSprite = spriteList.get(0);
//Matrix.setIdentityM(mMVPMatrix, 0);
//Matrix.rotateM(mMVPMatrix, 0, angleInDegrees, 0.0f, 0.0f, 1.0f);
//Matrix.translateM(mMVPMatrix, 0, currSprite.coordX, 0.0f, 0.0f);
//currSprite.coordX += 0.01f;
//currSprite.Draw(mMVPMatrix);
//number 2
currSprite = spriteList.get(0);
Matrix.setIdentityM(mMVPMatrix, 0);
Matrix.translateM(mMVPMatrix, 0, 0.0f, 0.0f, 0.0f);
Matrix.rotateM(mMVPMatrix, 0, angleInDegrees, 0.0f, 0.0f, +1.0f);
//float[] mTempMatrix = new float[16];
//mTempMatrix = mModelMatrix.clone();
//Matrix.multiplyMM(mMVPMatrix, 0, mMVPMatrix, 0, mRotateMatrix, 0);
//mTempMatrix = mMVPMatrix.clone();
//Matrix.multiplyMM(mMVPMatrix, 0, mTempMatrix, 0, mModelMatrix, 0);
//Matrix.setIdentityM(mMVPMatrix, 0);
currSprite.Draw(mMVPMatrix);
/*
//Set the camera position (View Matrix) //mtx, offset, eyex,y,z, centrex,y,z, upx,y,z
Matrix.setLookAtM(mVMatrix, 0,
0, 0, -10,
0f, 0f, 0f,
0f, 1.0f, 0.0f);
//Calculate the projection and view transformation
Matrix.multiplyMM(mMVPMatrix, 0, mProjMatrix, 0, mVMatrix, 0);
//zoom out a bit?
Matrix.translateM(mMVPMatrix, 0, 0, 0, 4.0f);
for (int i=0; i<numObjects; i++) {
//Create a rotation transformation for the triangle
//Matrix.setRotateM(mRotationMatrix, 0, mAngle, 0, 0, -1.0f);
Matrix.setRotateM(mRotationMatrix, 0, 0, 0, 0, -1.0f); //-1.0 = Z, for some reason need this. Grr
//Combine the rotation matrix with the projection and camera view
Matrix.multiplyMM(mMVPMatrix, 0, mRotationMatrix, 0, mMVPMatrix, 0);
//Draw Shape
//triangle.Draw(mMVPMatrix);
//sprite.Draw(mMVPMatrix);
currSprite = spriteList.get(i);
//Move the object to the passed initial coordinates?
//Matrix.translateM(mMVPMatrix, 0, currSprite.coordX, currSprite.coordY, currSprite.coordZ);
currSprite.Draw(mMVPMatrix);
}
*/
}
public void onSurfaceChanged(GL10 unused, int width, int height)
{
GLES20.glViewport(0, 0, width, height);
if (height == 0) {
height = 1; //incase of div 0 errors
}
float ratio = (float) width / height;
final float left = -ratio;
final float right = ratio;
final float bottom = -1.0f;
final float top = 1.0f;
final float near = 1.0f;
final float far = 10.f;
//This Projection Matrix is applied to object coordinates in the onDrawFrame() method
//Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 3, 7);
Matrix.frustumM(mProjMatrix, 0, left, right, bottom, top, near, far);
}
public static int loadShader(int type, String shaderCode)
{
//Create a Vertex Shader Type Or a Fragment Shader Type (GLES20.GL_VERTEX_SHADER OR GLES20.GL_FRAGMENT_SHADER)
int shader = GLES20.glCreateShader(type);
//Add The Source Code and Compile it
GLES20.glShaderSource(shader, shaderCode);
GLES20.glCompileShader(shader);
return shader;
}
}
请原谅我正在试验的OnDrawFrame（）中的注释代码，并且失败。
精灵等级
public class Sprite
{
//Reference to Activity Context
private final Context mActivityContext;
//Added for Textures
private final FloatBuffer mCubeTextureCoordinates;
private int mTextureUniformHandle;
private int mTextureCoordinateHandle;
private final int mTextureCoordinateDataSize = 2;
private int mTextureDataHandle;
private final String vertexShaderCode =
//Test
"attribute vec2 a_TexCoordinate;" +
"varying vec2 v_TexCoordinate;" +
//End Test
"uniform mat4 uMVPMatrix;" +
"attribute vec4 vPosition;" +
"void main() {" +
" gl_Position = vPosition * uMVPMatrix;" +
//Test
"v_TexCoordinate = a_TexCoordinate;" +
//End Test
"}";
private final String fragmentShaderCode =
"precision mediump float;" +
"uniform vec4 vColor;" +
//Test
"uniform sampler2D u_Texture;" +
"varying vec2 v_TexCoordinate;" +
//End Test
"void main() {" +
//"gl_FragColor = vColor;" +
"gl_FragColor = (vColor * texture2D(u_Texture, v_TexCoordinate));" +
"}";
private final int shaderProgram;
private final FloatBuffer vertexBuffer;
private final ShortBuffer drawListBuffer;
private int mPositionHandle;
private int mColorHandle;
private int mMVPMatrixHandle;
public float coordX;
public float coordY;
//public float coordZ;
// number of coordinates per vertex in this array
static final int COORDS_PER_VERTEX = 2;
static float spriteCoords[] = { -0.5f, 0.5f, // top left
-0.5f, -0.5f, // bottom left
0.5f, -0.5f, // bottom right
0.5f, 0.5f }; //top right
private short drawOrder[] = { 0, 1, 2, 0, 2, 3 }; //Order to draw vertices
private final int vertexStride = COORDS_PER_VERTEX * 4; //Bytes per vertex
// Set color with red, green, blue and alpha (opacity) values
//float color[] = { 0.63671875f, 0.76953125f, 0.22265625f, 1.0f };
float color[] = { 1f, 1f, 1f, 1.0f };
public Sprite(final Context activityContext, float initX, float initY, float initZ)
{
mActivityContext = activityContext;
this.coordX = initX;
this.coordY = initY;
//this.coordZ = initZ;
//ergh - will do manually for now. Paxo n00b
//just a 2D array, no need for Z nonsense
for (int i=0; i<spriteCoords.length; i++) {
spriteCoords[i] -= (i%2==0) ? coordX : coordY; //- works better than +
}
//float newPosMatrix[] = { initX, initY, 0f };
//adjust the vector coords accordingly
//Matrix.multiplyMV(spriteCoords, 0, newPosMatrix, 0, spriteCoords, 0);
//Initialize Vertex Byte Buffer for Shape Coordinates / # of coordinate values * 4 bytes per float
ByteBuffer bb = ByteBuffer.allocateDirect(spriteCoords.length * 4);
//Use the Device's Native Byte Order
bb.order(ByteOrder.nativeOrder());
//Create a floating point buffer from the ByteBuffer
vertexBuffer = bb.asFloatBuffer();
//Add the coordinates to the FloatBuffer
vertexBuffer.put(spriteCoords);
//Set the Buffer to Read the first coordinate
vertexBuffer.position(0);
// S, T (or X, Y)
// Texture coordinate data.
// Because images have a Y axis pointing downward (values increase as you move down the image) while
// OpenGL has a Y axis pointing upward, we adjust for that here by flipping the Y axis.
// What's more is that the texture coordinates are the same for every face.
final float[] cubeTextureCoordinateData =
{
//Front face
/*0.0f, 0.0f,
0.0f, 1.0f,
1.0f, 0.0f,
0.0f, 1.0f,
1.0f, 1.0f,
1.0f, 0.0f*/
/*-0.5f, 0.5f,
-0.5f, -0.5f,
0.5f, -0.5f,
0.5f, 0.5f*/
0f, 1f,
0f, 0f,
1f, 0f,
1f, 1f
};
mCubeTextureCoordinates = ByteBuffer.allocateDirect(cubeTextureCoordinateData.length * 4).order(ByteOrder.nativeOrder()).asFloatBuffer();
mCubeTextureCoordinates.put(cubeTextureCoordinateData).position(0);
//Initialize byte buffer for the draw list
ByteBuffer dlb = ByteBuffer.allocateDirect(spriteCoords.length * 2);
dlb.order(ByteOrder.nativeOrder());
drawListBuffer = dlb.asShortBuffer();
drawListBuffer.put(drawOrder);
drawListBuffer.position(0);
int vertexShader = MyGL20Renderer.loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
int fragmentShader = MyGL20Renderer.loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);
shaderProgram = GLES20.glCreateProgram();
GLES20.glAttachShader(shaderProgram, vertexShader);
GLES20.glAttachShader(shaderProgram, fragmentShader);
//Texture Code
GLES20.glBindAttribLocation(shaderProgram, 0, "a_TexCoordinate");
GLES20.glLinkProgram(shaderProgram);
//Load the texture
mTextureDataHandle = loadTexture(mActivityContext, R.drawable.cube);
}
public void Draw(float[] mvpMatrix)
{
//Add program to OpenGL ES Environment
GLES20.glUseProgram(shaderProgram);
//Get handle to vertex shader's vPosition member
mPositionHandle = GLES20.glGetAttribLocation(shaderProgram, "vPosition");
//Enable a handle to the triangle vertices
GLES20.glEnableVertexAttribArray(mPositionHandle);
//Prepare the triangle coordinate data
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, vertexBuffer);
//Get Handle to Fragment Shader's vColor member
mColorHandle = GLES20.glGetUniformLocation(shaderProgram, "vColor");
//Set the Color for drawing the triangle
GLES20.glUniform4fv(mColorHandle, 1, color, 0);
//Set Texture Handles and bind Texture
mTextureUniformHandle = GLES20.glGetAttribLocation(shaderProgram, "u_Texture");
mTextureCoordinateHandle = GLES20.glGetAttribLocation(shaderProgram, "a_TexCoordinate");
//Set the active texture unit to texture unit 0.
GLES20.glActiveTexture(GLES20.GL_TEXTURE0);
//Bind the texture to this unit.
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, mTextureDataHandle);
//Tell the texture uniform sampler to use this texture in the shader by binding to texture unit 0.
GLES20.glUniform1i(mTextureUniformHandle, 0);
//Pass in the texture coordinate information
mCubeTextureCoordinates.position(0);
GLES20.glVertexAttribPointer(mTextureCoordinateHandle, mTextureCoordinateDataSize, GLES20.GL_FLOAT, false, 0, mCubeTextureCoordinates);
GLES20.glEnableVertexAttribArray(mTextureCoordinateHandle);
//Get Handle to Shape's Transformation Matrix
mMVPMatrixHandle = GLES20.glGetUniformLocation(shaderProgram, "uMVPMatrix");
//Apply the projection and view transformation
GLES20.glUniformMatrix4fv(mMVPMatrixHandle, 1, false, mvpMatrix, 0);
//glTranslatef(0f, 0f, 0f);
//Draw the triangle
GLES20.glDrawElements(GLES20.GL_TRIANGLES, drawOrder.length, GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
//Disable Vertex Array
GLES20.glDisableVertexAttribArray(mPositionHandle);
}
public static int loadTexture(final Context context, final int resourceId)
{
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);
// 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_MIN_FILTER, GLES20.GL_NEAREST);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER, GLES20.GL_NEAREST);
// 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.");
}
return textureHandle[0];
}
}
现在，我不知道我是否正确地采用了这种方式，但我只是想在 spriteList 中设置Sprite对象的集合。
更具体地说，拥有3个对象的集合，然后响应屏幕触摸，并将对象设置为该位置的动画（但稍后会出现）
最初，我只是希望能够正确渲染这些对象（具有初始位置），然后在中心点（绕Z轴）旋转它们。
出于某种原因，TranslateM会扭曲纹理（就像关于Y轴一样）而不是实际沿着X / Y平面移动对象
非常感谢您提供的任何帮助。正如你所看到的，我对OpenGL相当陌生，并且对那些支持Android Studio和GLES2.0的有限教程没什么好运。
亲切的问候， 詹姆斯
答案 0 :(得分：-1)
我认为问题在于你没有将翻译矩阵乘以你的旋转矩阵。需要矩阵乘法来组合它们。