Rendering multiple squares fast?
- by Sam
so I'm doing my first steps with openGL development on android and I'm kinda stuck at some serious performance issues...
What I'm trying to do is render a whole grid of single colored squares on to the screen and I'm getting framerates of ~7FPS. The squares are 9px in size right now with one pixel border in between, so I get a few thousand of them.
I have a class "Square" and the Renderer iterates over all Squares every frame and calls the draw() method of each (just the iteration is fast enough, with no openGL code the whole thing runs smootlhy at 60FPS). Right now the draw() method looks like this:
// Prepare the square coordinate data
GLES20.glVertexAttribPointer(mPositionHandle, COORDS_PER_VERTEX,
GLES20.GL_FLOAT, false,
vertexStride, vertexBuffer);
// Set color for drawing the square
GLES20.glUniform4fv(mColorHandle, 1, color, 0);
// Draw the square
GLES20.glDrawElements(GLES20.GL_TRIANGLES, drawOrder.length,
GLES20.GL_UNSIGNED_SHORT, drawListBuffer);
So its actually only 3 openGL calls. Everything else (loading shaders, filling buffers, getting appropriate handles, etc.) is done in the Constructor and things like the Program and the handles are also static attributes.
What am I missing here, why is it rendering so slow?
I've also tried loading the buffer data into VBOs, but this is actually slower... Maybe I did something wrong though.
Any help greatly appreciated! :)
