如何在OpenGL ES（iPhone）中批量渲染精灵

Question

I have a game that renders a bunch of sprites (several hundred), almost all of which are using the same texture. Currently, I'm calling glDrawArrays(...) for each one, which I recently discovered was very inefficient. After doing some research, I've learned that I need to put all my vertices for every sprite into one big vertex buffer, and call glDrawArrays(...) just once using that. However, when I do so it only draws the first sprite, and the other 200 are blank.

blueSpriteVertices[blueBatchNum * 4] = Vertex3DMake(xloc, yloc, zloc);
blueSpriteVertices[blueBatchNum * 4 + 1] = Vertex3DMake(xloc + size, yloc, zloc);
blueSpriteVertices[blueBatchNum * 4 + 2] = Vertex3DMake(xloc, yloc + size, zloc);
blueSpriteVertices[blueBatchNum * 4 + 3] = Vertex3DMake(xloc + size, yloc + size, zloc);
blueBatchNum++;
//^^This block of code^^ is called iteratively, adding data for various sprites
//(around 200) to the vertex array. "xloc", "yloc", etc. are private members of 
//this sprite class


//Draw the whole batch
glEnableClientState(GL_VERTEX_ARRAY);
glEnable(GL_TEXTURE_2D);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glColor4f(1, 1, 1, 1);

//This code is actually in the Texture2D class implementation, hence "_name"
//and "coordinates"
glBindTexture(GL_TEXTURE_2D, _name);
glVertexPointer(3, GL_FLOAT, 0, blueSpriteVertices);
glTexCoordPointer(2, GL_FLOAT, 0, coordinates);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

glDisableClientState(GL_TEXTURE_COORD_ARRAY);
glDisable(GL_TEXTURE_2D);
glDisableClientState(GL_VERTEX_ARRAY);

Answer 1

I finally solved this problem by using GL_TRIANGLES instead of GL_TRIANGLE_STRIP, and handled the triangle strips manually. By doing so I was able to eliminate all the "strips" that it was interpreting in between my sprites. Works like a charm now, and the batching definitely improved my game's performance astronomically.

Answer 2

使用（GL_TRIANGLES而不是GL_TRIANGLE_STRIP适用于我（在Android上）

glDrawElements(GL_TRIANGLES, 6 * mSpriteCounter, GL_UNSIGNED_SHORT, (char*) NULL);

Answer 3

The glDrawArrays() last parameter should contain the number of vertices (in your case you have only 4). Also you must have the same number of texture coordinates to match the drawn vertices!