我编程使用OpenGL ES 2.0的一个Android 2D游戏。当我画我的精灵后备缓冲区我画灯一个FBO，并尝试再次融入到后台缓冲区。 当我画的FBO的帧缓冲，即使trasparent没有任何颜色，帧率下降60至30对三星Galaxy W（它有一个的Adreno 205 GPU为）。我到处搜寻，并尝试了一切，即使我绘制一个精灵在现场和混合一trasparent FBO纹理帧率下降画面。我尝试过其他游戏上手机的灯光效果，它们运行良好，几乎每场比赛罚款那个电话，我相信他们使用framebuffer也是如此。 在Galaxy SII（马里400 GPU）运行良好，我很新的OpenGL的，所以我相信，我犯了一个错误的地方，我分享我的code。

I am programming an Android 2d game using opengl es 2.0. After I draw my sprites to the backbuffer I draw lights to a FBO and try to blend it to the back buffer again. When I draw the FBO to the framebuffer, even trasparent without any color, the framerates drops from 60 to 30 on a Samsung Galaxy w (it has an adreno 205 as gpu). I searched everywhere and tried everything, even if I draw a single sprite on the scene and blend a trasparent FBO texture to the screen the framerate drops. I tried other games with lighting effects on that phone and they run fine, almost every game is fine on that phone, I believe they use the framebuffer as well. On the Galaxy SII (mali 400 gpu) runs fine, I am quite new to opengl so I believe I am making a mistake somewhere, I share my code.

// Create a framebuffer and renderbuffer
GLES20.glGenFramebuffers(1, fb, offset);
GLES20.glGenRenderbuffers(1, depthRb, offset);

// Create a texture to hold the frame buffer
GLES20.glGenTextures(1, renderTex, offset);
GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, renderTex[offset]);

GLES20.glTexImage2D(GLES20.GL_TEXTURE_2D, 0, GLES20.GL_RGBA,
                    screenWidth, screenHeight, 0,
                    GLES20.GL_RGBA, GLES20.GL_UNSIGNED_BYTE,
                    null);


GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_S,
                       GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_WRAP_T,
                       GLES20.GL_CLAMP_TO_EDGE);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MAG_FILTER,
                       GLES20.GL_LINEAR);
GLES20.glTexParameteri(GLES20.GL_TEXTURE_2D, GLES20.GL_TEXTURE_MIN_FILTER,
                       GLES20.GL_LINEAR);

//bind renderbuffer
GLES20.glBindRenderbuffer(GLES20.GL_RENDERBUFFER, depthRb[offset]);

GLES20.glRenderbufferStorage(GLES20.GL_RENDERBUFFER, GLES20.GL_DEPTH_COMPONENT16,
                             screenWidth, screenHeight);

// bind the framebuffer
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, fb[offset]);

// specify texture as color attachment
GLES20.glFramebufferTexture2D(GLES20.GL_FRAMEBUFFER, GLES20.GL_COLOR_ATTACHMENT0,
                              GLES20.GL_TEXTURE_2D, renderTex[offset], 0);

// specify depth_renderbufer as depth attachment
GLES20.glFramebufferRenderbuffer(GLES20.GL_FRAMEBUFFER, GLES20.GL_DEPTH_ATTACHMENT,
                                 GLES20.GL_RENDERBUFFER, depthRb[0]);

// Check FBO status.
int status = GLES20.glCheckFramebufferStatus(GLES20.GL_FRAMEBUFFER);

if ( status == GLES20.GL_FRAMEBUFFER_COMPLETE )
{
    Log.d("GLGame framebuffer creation", "Framebuffer complete");
}


// set default framebuffer
GLES20.glBindFramebuffer(GLES20.GL_FRAMEBUFFER, 0);

我做一次表面创作。不知道是否是正确的。我把质感和帧缓冲IDS切换到他们时，我需要的。 我的绘画code：

I do this once on surface creation. Not sure if is correct. I keep the texture and framebuffer ids to switch to them when I need. My drawing code:

GLES20.glBindTexture(GLES20.GL_TEXTURE_2D, textureId);
ShaderProgram program = glgame.getProgram();

//put vertices in the floatbuffer
mTriangleVertices.put(vertices, 0, len);
mTriangleVertices.flip();

GLES20.glVertexAttribPointer(program.POSITION_LOCATION, 2, GLES20.GL_FLOAT, false,
                             TRIANGLE_VERTICES_DATA_STRIDE_BYTES, mTriangleVertices);

//preparing parameter for texture position
mTriangleVertices.position(TRIANGLE_VERTICES_DATA_UV_OFFSET);
GLES20.glEnableVertexAttribArray(program.POSITION_LOCATION);

//preparing parameter for texture coords
GLES20.glVertexAttribPointer(program.TEXTURECOORD_LOCATION, 2, GLES20.GL_FLOAT,
                             false, TRIANGLE_VERTICES_DATA_STRIDE_BYTES,
                             mTriangleVertices);

//set projection matrix
GLES20.glEnableVertexAttribArray(program.TEXTURECOORD_LOCATION);
GLES20.glUniformMatrix4fv(program.MATRIX_LOCATION, 1, false, matrix, 0);

//draw triangle with indices to form a rectangle
GLES20.glDrawElements(GLES20.GL_TRIANGLES, numSprites * 6, GLES20.GL_UNSIGNED_SHORT,
                      indicesbuf);

//clear buffers
mTriangleVertices.clear();
mVertexColors.clear();

一切呈现在屏幕上正确，但性能也毁了就在我画的FBO的质感。 非常感谢你的帮助。我很努力在这，并没有找到一个解决方案。

Everything is rendered on screen correctly, but the performance are ruined just when I draw the FBO texture. Thank you very much for your help. I worked very hard on this and didn't find a solution.

推荐答案

据高通的文档，你需要每glbindframebuffer后glclear，这是关系到瓷砖结构的问题，如果您切换的帧缓冲区，数据需要被复制从fastmem正常的内存来保存当前帧缓冲和slowmem快纪念品获得新绑定框架的内容，如果你正在清理刚过glbind没有数据从slowmem复制到fastmem和你节省时间，但你需要重新设计渲染管线的时候，所以这将避免读取数据的来回慢速和快速存储器之间，因此尝试每个绑定后做glclear，它应该帮助，您还可以使用肾上腺探查，以获取有关问题的调用更多的信息，但我怀疑它会帮助的Adreno200我试图让两个缓冲区的模糊和我结束与10fps的，bindframebuffer通话可能需要长达20毫秒，如果它不被清除，如果是它应该结束在2毫秒。

According to qualcomm docs, you need to glclear after every glbindframebuffer, this is a problem related to tiled architecture, if you are switching framebuffers, data need to get copied from fastmem to normal memory to save current framebuffer and from slowmem to fast mem to get contents of newly binded frame, in case you are clearing just after glbind no data is copied from slowmem to fastmem and you are saving time, but you need to redesign your render pipeline often, so it will avoid reading data back and forth between slow and fast memory, so try to do glclear after each bind and it should help, you can also use adreno profiler to get additional information about problematic calls, but i doubt it will help with adreno200 i am trying to get two buffers for blur and i am ending with 10fps, bindframebuffer call can take up to 20msec if its not cleared, if it is it should end at 2ms.