view src/video/bwindow/SDL_BView.h @ 5053:b5b42be9333c

Fixed bug #1026 Vittorio Giovara 2010-07-16 19:09:28 PDT i was reading SDL_renderer_gles and i noticed that every time we there is some gl call the gl state is modified with a couple of glEnableClientState()/glDisableClientState. While this is completely fine for desktops systems, this is a major performace kill on mobile devices, right where opengles is implemented. Normal practice in this case is to update the glstate once, keep it always the same and disable/enable other states only in very special occasions. On the web there's plenty of documentation (on the top of my head http://developer.apple.com/iphone/library/documentation/3DDrawing/Conceptual/OpenGLES_ProgrammingGuide/Performance/Performance.html#//apple_ref/doc/uid/TP40008793-CH105-SW5 ) and i personally tried this. I modified my code and got a 10 fps boost, then modified SDL_render_gles and shifted from 40 fps to 50 fps alone -- considering that i started from ~30fps i got an 80% performance increase with this technique. I have attached a dif of my changes, hope that it will be included in mainstream.
author Sam Lantinga <slouken@libsdl.org>
date Wed, 19 Jan 2011 23:56:16 -0800
parents f7b03b6838cb
children b530ef003506
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2010 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#ifndef _SDL_BView_h
#define _SDL_BView_h

/* This is the event handling and graphics update portion of SDL_BWin */

extern "C"
{
#include "../../events/SDL_events_c.h"
};

class SDL_BView:public BView
{
  public:
    SDL_BView(BRect frame):BView(frame, "SDL View", B_FOLLOW_ALL_SIDES,
                                 (B_WILL_DRAW | B_FRAME_EVENTS))
    {
        image = NULL;
        xoff = yoff = 0;
        SetViewColor(0, 0, 0, 0);
        SetHighColor(0, 0, 0, 0);
    }
    virtual ~ SDL_BView()
    {
        SetBitmap(NULL);
    }
    /* Set drawing offsets for fullscreen mode */
    virtual void SetXYOffset(int x, int y)
    {
        xoff = x;
        yoff = y;
    }
    virtual void GetXYOffset(int &x, int &y)
    {
        x = xoff;
        y = yoff;
    }
    /* The view changed size. If it means we're in fullscreen, we
     * draw a nice black box in the entire view to get black borders.
     */
    virtual void FrameResized(float width, float height)
    {
        BRect bounds;
        bounds.top = bounds.left = 0;
        bounds.right = width;
        bounds.bottom = height;
        /* Fill the entire view with black */
        FillRect(bounds, B_SOLID_HIGH);
        /* And if there's an image, redraw it. */
        if (image) {
            bounds = image->Bounds();
            Draw(bounds);
        }
    }

    /* Drawing portion of this complete breakfast. :) */
    virtual void SetBitmap(BBitmap * bitmap)
    {
        if (image) {
            delete image;
        }
        image = bitmap;
    }
    virtual void Draw(BRect updateRect)
    {
        if (image) {
            if (xoff || yoff) {
                BRect dest;
                dest.top = updateRect.top + yoff;
                dest.left = updateRect.left + xoff;
                dest.bottom = updateRect.bottom + yoff;
                dest.right = updateRect.right + xoff;
                DrawBitmap(image, updateRect, dest);
            } else {
                DrawBitmap(image, updateRect, updateRect);
            }
        }
    }
    virtual void DrawAsync(BRect updateRect)
    {
        if (xoff || yoff) {
            BRect dest;
            dest.top = updateRect.top + yoff;
            dest.left = updateRect.left + xoff;
            dest.bottom = updateRect.bottom + yoff;
            dest.right = updateRect.right + xoff;;
            DrawBitmapAsync(image, updateRect, dest);
        } else {
            DrawBitmapAsync(image, updateRect, updateRect);
        }
    }

  private:
    BBitmap * image;
    int xoff, yoff;
};

#endif /* _SDL_BView_h */
/* vi: set ts=4 sw=4 expandtab: */