优化 OpenGL ES 操作？
我使用以下代码在屏幕上绘制字符（每个 UTF8 字符都是一个纹理）：
int row = 0;
glTexCoordPointer(2, GL_FLOAT, 0, texCoords);
glVertexPointer(2, GL_FLOAT, 0, vertices);
for (StdStr* line in _lines) {
const char* str = [line cString];
for (int i = 0; i < strlen(str); i++) {
((XX::OGL::GLESContext*)context)->viewport(C_WIDTH*i,
C_HEIGHT*row,
C_WIDTH,
C_HEIGHT);
glColor4f(1.0, 1.0, 1.0, 1.0);
glBindTexture(GL_TEXTURE_2D, _textures[0] + *(str + i));
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
row++;
}
当字符很多时，代码运行时间会更长。在本例中，几乎 99% 的时间都花费在 glDrawArrays 例程中。是否可以最大程度地减少对 glDrawArrays 的调用量？ OpenGL ES 版本为 1.1。
I'm using the following code to draw characters on screen (each UTF8 character is a texture):
int row = 0;
glTexCoordPointer(2, GL_FLOAT, 0, texCoords);
glVertexPointer(2, GL_FLOAT, 0, vertices);
for (StdStr* line in _lines) {
const char* str = [line cString];
for (int i = 0; i < strlen(str); i++) {
((XX::OGL::GLESContext*)context)->viewport(C_WIDTH*i,
C_HEIGHT*row,
C_WIDTH,
C_HEIGHT);
glColor4f(1.0, 1.0, 1.0, 1.0);
glBindTexture(GL_TEXTURE_2D, _textures[0] + *(str + i));
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
}
row++;
}
When there are a lot of characters, the code takes longer to run. In this case, almost 99% of the time is spent in the glDrawArrays routine. Is it possible to minimise the amount of calls to glDrawArrays? The OpenGL ES version is 1.1.
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（1）
实际上我认为你应该尝试限制对
viewport、glBindTexture和glDrawArrays的调用量。从技术上讲，您应该将所有角色打包在一个纹理中，以便您可以将其绑定一次。
然后，您可以像实际一样在循环中计算顶点和纹理坐标，但自己进行视口数学计算，并将结果累积到 CPU 数组中。一旦你的数组构成，你应该提交一次绘制调用，提供这个数组。
您可能可以在这里找到灵感：
http://www.angelcode.com/products/bmfont/
http://sourceforge.net/projects/oglbmfont/
Actually I think that you should try to limit the amount of calls to
viewport,glBindTextureandglDrawArrays.Technically, you should pack all your characters in a single texture, so that you can bind it once.
Then, you could compute the vertices and texcoords in a loop like you do actually, but doing the viewport maths yourself, and accumulating results in a CPU array. Once your array constituted, you should submit a draw call once, providing this array.
You can probably find inpiration here:
http://www.angelcode.com/products/bmfont/
http://sourceforge.net/projects/oglbmfont/