使用OpenGL ES 2.0绘制2D图像

我一直在努力使用openGL ES 2.0 for Android从jpg / png文件中绘制2D图像。 我看到的每个地方的教程都是用于纹理化3D图像,因此粗略地弄清楚如何绘制常规的2D Sprite。 我得到了一个正方形来绘制和旋转但是一旦它变成了纹理,我必须搞砸了某个地方,因为我一直收到一个错误,说DrawElements没有绑定任何数据,但如果我注释掉任何与纹理相关的代码,它工作正常。

任何帮助将不胜感激。

这是我的Sprite类和Renderer类的代码:

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 = (v_Color * 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; // 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 }; public Sprite(final Context activityContext) { mActivityContext = activityContext; //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 }; 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.brick); } 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); //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]; } } 

我的渲染器类:

 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]; //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); //Initialize Shapes //triangle = new Triangle(); sprite = new Sprite(mActivityContext); } public void onDrawFrame(GL10 unused) { //Redraw background color 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); //Create a rotation transformation for the triangle Matrix.setRotateM(mRotationMatrix, 0, mAngle, 0, 0, -1.0f); //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); } public void onSurfaceChanged(GL10 unused, int width, int height) { GLES20.glViewport(0, 0, width, height); float ratio = (float) width / height; //This Projection Matrix is applied to object coordinates in the onDrawFrame() method Matrix.frustumM(mProjMatrix, 0, -ratio, ratio, -1, 1, 3, 7); } 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; } } 

Solutions Collecting From Web of "使用OpenGL ES 2.0绘制2D图像"

“v_TexCoordinate = a_TexCoordinate”+

本来应该

“v_TexCoordinate = a_TexCoordinate;” +

显然我忘记了一个分号,现在我意识到当我弄乱愚蠢的事情时,我多少依靠我的IDE告诉我哈哈。

在fragmentShaderCode中使用variablesvColor命名(或使用)时出错。 这里你的variables名为vColor:

 uniform vec4 vColor; 

在这一行中,它的名称为v_Color

 gl_FragColor = (v_Color * texture2D(u_Texture, v_TexCoordinate)); 

尝试使用以下纹理坐标:

final float [] cubeTextureCoordinateData = {
0.5,-0.5,0.5,0.5,-0.5,0.5,-0.5,-0.5};

它的工作。 非常感谢你。

我也会在着色器中更改它

  gl_Position = vPosition * uMVPMatrix; 

对此

  gl_Position = uMVPMatrix * vPosition; 

在尝试翻译图像的位置时会有所不同。

在分配VertexAttribPointer之前,解决方案可以像启用mTextureCoord一样简单;