以下是一个使用Android OpenGL ES库在绘制对象时关联信息的示例代码:
public class DrawableObject {
private FloatBuffer vertexBuffer;
private FloatBuffer textureBuffer;
private int program;
private int positionHandle;
private int textureCoordHandle;
public DrawableObject(float[] vertices, float[] textureCoords) {
// 将顶点坐标和纹理坐标转换为FloatBuffer
ByteBuffer bb = ByteBuffer.allocateDirect(vertices.length * 4);
bb.order(ByteOrder.nativeOrder());
vertexBuffer = bb.asFloatBuffer();
vertexBuffer.put(vertices);
vertexBuffer.position(0);
ByteBuffer tb = ByteBuffer.allocateDirect(textureCoords.length * 4);
tb.order(ByteOrder.nativeOrder());
textureBuffer = tb.asFloatBuffer();
textureBuffer.put(textureCoords);
textureBuffer.position(0);
// 创建并编译顶点着色器和片段着色器
int vertexShader = MyGLRenderer.loadShader(GLES20.GL_VERTEX_SHADER, vertexShaderCode);
int fragmentShader = MyGLRenderer.loadShader(GLES20.GL_FRAGMENT_SHADER, fragmentShaderCode);
// 创建OpenGL ES程序并链接着色器
program = GLES20.glCreateProgram();
GLES20.glAttachShader(program, vertexShader);
GLES20.glAttachShader(program, fragmentShader);
GLES20.glLinkProgram(program);
}
public void draw() {
// 使用OpenGL ES程序
GLES20.glUseProgram(program);
// 获取顶点着色器中的属性位置
positionHandle = GLES20.glGetAttribLocation(program, "vPosition");
textureCoordHandle = GLES20.glGetAttribLocation(program, "vTexCoord");
// 启用顶点属性数组并将顶点坐标和纹理坐标关联到顶点着色器的属性位置
GLES20.glEnableVertexAttribArray(positionHandle);
GLES20.glVertexAttribPointer(positionHandle, COORDS_PER_VERTEX, GLES20.GL_FLOAT, false, vertexStride, vertexBuffer);
GLES20.glEnableVertexAttribArray(textureCoordHandle);
GLES20.glVertexAttribPointer(textureCoordHandle, COORDS_PER_TEXTURE, GLES20.GL_FLOAT, false, textureStride, textureBuffer);
// 绘制对象
GLES20.glDrawArrays(GLES20.GL_TRIANGLES, 0, vertexCount);
// 禁用顶点属性数组
GLES20.glDisableVertexAttribArray(positionHandle);
GLES20.glDisableVertexAttribArray(textureCoordHandle);
}
}
public class MyGLRenderer implements GLSurfaceView.Renderer {
private DrawableObject drawableObject;
@Override
public void onSurfaceCreated(GL10 gl10, EGLConfig eglConfig) {
// 初始化OpenGL ES并设置背景色等
GLES20.glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
// 创建DrawableObject对象
float[] vertices = {...}; // 定义顶点坐标
float[] textureCoords = {...}; // 定义纹理坐标
drawableObject = new DrawableObject(vertices, textureCoords);
}
@Override
public void onSurfaceChanged(GL10 gl10, int width, int height) {
// 设置视口尺寸
GLES20.glViewport(0, 0, width, height);
}
@Override
public void onDrawFrame(GL10 gl10) {
// 清除颜色缓冲区
GLES20.glClear(GLES20.GL_COLOR_BUFFER_BIT);
// 绘制DrawableObject对象
drawableObject.draw();
}
public static int loadShader(int type, String shaderCode) {
// 创建着色器对象
int shader = GLES20.glCreateShader(type);
// 将着色器源码加载到着色器对象中
GLES20.glShaderSource(shader, shaderCode);
// 编译着色器
GLES20.glCompileShader(shader);
return shader;
}
}
注意:在以上示例中,需要定义顶点着色器和片段着色器的源代码,并将其分别存储在vertexShaderCode和fragmentShaderCode字符串变量中。此外,还需要提供顶点坐标和纹理