我有一个专门为图形使用 glDrawTexfoes() 的游戏。当然是二维的。直到现在，我在绘制图形时都没有拉伸它们：我有 2 套，一套小一套，适用于不同的设备。这种方法已经达到了极限（坦率地说，我不应该使用它——但那是两年前的事了）。
所以现在我正在尝试使用一组图像并使用 glDrawTexfoes 来缩放它们以填充显示。除了我平铺图像的地方之外，它大部分都在工作。我已经包含了显示结果的图像。垂直线不应该在那里。
我已经尽可能多地使用纹理参数，但我无法摆脱这个问题，所以我转向 SO。这里有一些细节：图像不是2的幂。它没有使用精灵表，每个精灵都有自己的位图。
我使用此代码创建纹理
bitmap.prepareTexture(_glMaxTextureSize);
gl.glGenTextures(1, mTextureNameWorkspace, 0);
int error = gl.glGetError();
if (error != GL10.GL_NO_ERROR) {
Log.d("Texture Load 1", "GLError: " + error + " (" + GLU.gluErrorString(error) + "): " + bitmap.toString() );
}
assert error == GL10.GL_NO_ERROR;
bitmap.textureName = mTextureNameWorkspace[0];
gl.glBindTexture(GL10.GL_TEXTURE_2D, bitmap.textureName);
error = gl.glGetError();
if (error != GL10.GL_NO_ERROR) {
Log.d("Texture Load 2", "GLError: " + error + " (" + GLU.gluErrorString(error) + "): " + bitmap.toString());
}
assert error == GL10.GL_NO_ERROR;
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MIN_FILTER, GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_MAG_FILTER, GL10.GL_LINEAR);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_S, GL10.GL_REPEAT);
gl.glTexParameterf(GL10.GL_TEXTURE_2D, GL10.GL_TEXTURE_WRAP_T, GL10.GL_REPEAT);
gl.glTexEnvf(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE, GL10.GL_REPLACE); //GL10.GL_REPLACE);
GLUtils.texImage2D(GL10.GL_TEXTURE_2D, 0, bitmap.textureHanlde, 0);
error = gl.glGetError();
if (error != GL10.GL_NO_ERROR) {
Log.d("Texture Load 3", "GLError: " + error + " (" + GLU.gluErrorString(error) + "): " + bitmap.toString());
}
bitmap.releaseTextureBitmap();
assert error == GL10.GL_NO_ERROR;
mCropWorkspace[0] = 0;
mCropWorkspace[1] = bitmap.getHeight();
mCropWorkspace[2] = bitmap.getWidth();
mCropWorkspace[3] = -bitmap.getHeight();
((GL11) gl).glTexParameteriv(GL10.GL_TEXTURE_2D, GL11Ext.GL_TEXTURE_CROP_RECT_OES, mCropWorkspace, 0);
error = gl.glGetError();
if (error != GL10.GL_NO_ERROR) {
Log.d("Texture Load 4", "GLError: " + error + " (" + GLU.gluErrorString(error) + "): " + bitmap.toString());
}
assert error == GL10.GL_NO_ERROR;
使用以下代码创建 opengl 上下文
/*
* Some one-time OpenGL initialization can be made here probably based
* on features of this particular context
*/
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_FASTEST);
gl.glClearColor(0.0f, 0.0f, 0.0f, 1);
gl.glShadeModel(GL10.GL_FLAT);
gl.glDisable(GL10.GL_DEPTH_TEST);
gl.glEnable(GL10.GL_TEXTURE_2D);
/*
* By default, OpenGL enables features that improve quality but reduce
* performance. One might want to tweak that especially on software
* renderer.
*/
gl.glDisable(GL10.GL_DITHER);
gl.glDisable(GL10.GL_LIGHTING);
gl.glTexEnvx(GL10.GL_TEXTURE_ENV, GL10.GL_TEXTURE_ENV_MODE, GL10.GL_MODULATE);
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
视口按以下方式设置
float scaleX = (float)w / _screenWidth;
float scaleY = (float)h / _screenHeight;
final int viewportWidth = (int)(_screenWidth * scaleX);
final int viewportHeight = (int)(_screenHeight * scaleY);
gl.glViewport(0, 0, viewportWidth, viewportHeight);
mScaleX = scaleX;
mScaleY = scaleY;
/*
* Set our projection matrix. This doesn't have to be done each time we
* draw, but usually a new projection needs to be set when the viewport
* is resized.
*/
float ratio = (float) _screenWidth / _screenHeight;
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
gl.glFrustumf(-ratio, ratio, -1, 1, 1, 10);
最后，请原谅代码墙，绘图完成了
gl.glShadeModel(GL10.GL_FLAT);
gl.glEnable(GL10.GL_BLEND);
gl.glBlendFunc(GL10.GL_ONE, GL10.GL_ONE_MINUS_SRC_ALPHA);
gl.glColor4x(0x10000, 0x10000, 0x10000, 0x10000);
gl.glViewport(0, 0, (int)viewWidth, (int)viewHeight);
gl.glMatrixMode(GL10.GL_PROJECTION);
gl.glLoadIdentity();
gl.glOrthof(0, viewWidth, viewHeight, 0.0f, 0.0f, 1.0f);
gl.glMatrixMode(GL10.GL_MODELVIEW);
gl.glLoadIdentity();
gl.glEnable(GL10.GL_TEXTURE_2D);
[loop over sprites]
final float screenScale = 800/600f; // hardcoded to test stuff out
final float snappedX = ((x + transX)*screenScale); //+ e.speedX * interpolation;
final float snappedY = _screenHeight - (y + height + transY ) * screenScale;//+ e.speedY * interpolation);
final int texName = ob.textureName;
gl.glBindTexture(GL10.GL_TEXTURE_2D, texName);
_cropWorkspace[0] = left;
_cropWorkspace[1] = top + height;
_cropWorkspace[2] = width;
_cropWorkspace[3] = -height;
if( operation == Drawer.MIRROR_X )
{
_cropWorkspace[0] = left + width;
_cropWorkspace[2] = -width;
}
((GL11) gl).glTexParameteriv(GL10.GL_TEXTURE_2D, GL11Ext.GL_TEXTURE_CROP_RECT_OES, _cropWorkspace, 0);
((GL11Ext) gl).glDrawTexfOES(snappedX, snappedY, 1, width * screenScale, height * screenScale );