我在 Android 中使用 OpenGL 的纹理映射有问题。基本上问题是，大多数正方形（我用来绘制 2 个三角形的类）都被正确绘制，也就是说它们上的纹理完全符合它们应有的状态，并且一切都很甜美。但是有些方块画得有点奇怪。基本上，从顶部开始的每条下一条水平线都会向左移动大约 1 个像素。这是一个示例图像： http ://postimage.org/image/1la0mr99g/ 这就是它的绘制方式（上面的按钮是完全相同的，但纹理不同）： http: //postimage.org /image/1lafildpg/
这是负责将图像绘制到屏幕的类。我还必须补充一点，一旦创建了 Square，我就会继续使用，并且以后可能会重新映射一些纹理，但是对于绘制错误的图像而言并非如此（实际上，我已经重新映射了一些其他图像以使其绘制得很好）。所以基本上，通过查看代码，我不知道可能出了什么问题，因为大多数正方形都被正确绘制，并且我看不到任何错误。此外，我实际上有 2 个按钮，它们的大小完全相同，它们的图像也大小相同 - 但其中一个被绘制得很好，而另一个被“歪斜”。创建这些按钮的代码实际上是相同的，所以我完全不知道出了什么问题。
public class GLSquare {
private float width, height;
private FloatBuffer vertexBuffer; // buffer holding the vertices
private float vertices[]; /* = {
-1.0f, 1.0f, 0.0f, // V1 - bottom left
-1.0f, -1.0f, 0.0f, // V2 - top left
1.0f, 1.0f, 0.0f, // V3 - bottom right
1.0f, -1.0f, 0.0f // V4 - top right
};
*/
private FloatBuffer textureBuffer; // buffer holding the texture coordinates
private float texture[] = {
// Mapping coordinates for the vertices
0.0f, 1.0f, // top left (V2)
0.0f, 0.0f, // bottom left (V1)
1.0f, 1.0f, // top right (V4)
1.0f, 0.0f // bottom right (V3)
};
/** The texture pointer */
private int[] textures = new int[1];
public GLSquare(float width, float height) {
this.width = width;
this.height = height;
vertices = new float[12];
vertices[0] = -(width/2); vertices[1] = (height/2); vertices[2] = 0.0f;// V1 - bottom left
vertices[3] = -(width/2); vertices[4] = -(height/2); vertices[5] = 0.0f;// V2 - top left
vertices[6] = width/2; vertices[7] = (height/2); vertices[8] = 0.0f;// V3 - bottom right
vertices[9] = width/2; vertices[10] = -(height/2); vertices[11] = 0.0f;// V4 - top right
// a float has 4 bytes so we allocate for each coordinate 4 bytes
ByteBuffer byteBuffer = ByteBuffer.allocateDirect(vertices.length * 4);
byteBuffer.order(ByteOrder.nativeOrder());
// allocates the memory from the byte buffer
vertexBuffer = byteBuffer.asFloatBuffer();
// fill the vertexBuffer with the vertices
vertexBuffer.put(vertices);
// set the cursor position to the beginning of the buffer
vertexBuffer.position(0);
byteBuffer = ByteBuffer.allocateDirect(texture.length * 4);
byteBuffer.order(ByteOrder.nativeOrder());
textureBuffer = byteBuffer.asFloatBuffer();
textureBuffer.put(texture);
textureBuffer.position(0);
}
public float getWidth(){
return width;
}
public float getHeight(){
return height;
}
public void loadGLTexture(GL10 gl, Bitmap bitmap) {
// Generate a texture pointer
gl.glGenTextures(1, textures, 0);
// Bind texture to array
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
// create nearest filtered texture
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_NEAREST);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
// Use Android GLUtils to specify a two-dimensional texture image from our bitmap
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap, 0);
// Clean up
bitmap.recycle();
}
public void draw(GL10 gl, float x, float y, float scaleX, float scaleY, float angle) {
gl.glPushMatrix();
// bind the previously generated texture
gl.glBindTexture(GL10.GL_TEXTURE_2D, textures[0]);
// Point to our buffers
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glEnableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
// Set the face rotation
gl.glFrontFace(GL10.GL_CW);
// Point to our vertex buffer
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, vertexBuffer);
gl.glTexCoordPointer(2, GL10.GL_FLOAT, 0, textureBuffer);
//translate to the wanted x,y coord
gl.glTranslatef(x, y, 0.0f);
if(angle != 0.0f){
gl.glRotatef(angle, 0.0f, 0.0f, 1.0f);
}
if(scaleX != 1.0f && scaleY != 1.0f){
gl.glScalef(scaleX, scaleY, 0.0f);
}
// Draw the vertices as triangle strip
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, vertices.length / 3);
//Disable the client state before leaving
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDisableClientState(GL10.GL_TEXTURE_COORD_ARRAY);
gl.glPopMatrix();
}
}