Question

Im using openGL with GLKit to make a tiles-based game. In the game, around 1024 tiles are placed in the screen, the problem is that I’m rendering the tiles every time drawInRect is called, and I’m having a lost of performance very big.

This is how I render (tilesArray is static, ballsArray is moving around the screen):

- (void)glkView:(GLKView *)view drawInRect:(CGRect)rect
{
    glClearColor(1, 1, 1, 1);
    glClear(GL_COLOR_BUFFER_BIT);    
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glEnable(GL_BLEND);


    for (int i = 0; i < [self.tilesArray count]; i++){            
        RPSprite *tempTile = [self.tilesArray objectAtIndex:i];
        [tempTile render];
    }


    for (RPSprite *ball in self.ballsArray){
        [ball render];
    }
}

As I said, tilesArray is static in the screen, but ballsArray is moving around the screen very fast (with every update). If I put only the balls, it goes very fast, if I add the tiles, it goes very slow (only tried in simulator)

This is how I render:

- (GLKMatrix4) modelMatrix {

    GLKMatrix4 modelMatrix = GLKMatrix4Identity;  
    modelMatrix = GLKMatrix4Translate(modelMatrix, self.position.x,320 - self.position.y - self.textureInfo.height, 0);
    return modelMatrix;

}

- (void)render { 

    self.effect.texture2d0.name = self.textureInfo.name;
    self.effect.texture2d0.enabled = YES;
    self.effect.transform.modelviewMatrix = self.modelMatrix;

    [self.effect prepareToDraw];

    long offset = (long)&_quad;

    glEnableVertexAttribArray(GLKVertexAttribPosition);
    glEnableVertexAttribArray(GLKVertexAttribTexCoord0);

    glVertexAttribPointer(GLKVertexAttribPosition, 2, GL_FLOAT, GL_FALSE, sizeof(TexturedVertex), (void *) (offset + offsetof(TexturedVertex, geometryVertex)));
    glVertexAttribPointer(GLKVertexAttribTexCoord0, 2, GL_FLOAT, GL_FALSE, sizeof(TexturedVertex), (void *) (offset + offsetof(TexturedVertex, textureVertex)));

    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);

}

Answer 1

I fixed it reducing the size of the images used by the tiles, and putting a specific framerate in the view.