Drawing speed problems...

linkingfire

22y3.5kGDI+

Ok, I'm creating a game. Nothing too fancy, no dreams of commercial success, I'm doing it to teach myself multithreading. So I'm not going to sit here and hype how great my code is, especially since I have a problem. A big problem. I've tried it with both a panel and no panel. I'm trying to draw the "area" of the level that the player is in to the screen. So I have the program create the graphic, but when I tell the image to draw, it is SO slow. Three seconds sometimes. This is a bit of a problem. Ok, the exact problem is that I have an image, a "ship" that is in the center of the screen, that I rotate, etc. I read a file, generate the level image and everything, and then take the relevant "chunk" and drawing it to the screen. I figured this would be faster than either drawing the entire image, or drawing through a for-loop or something. No matter what I do though, it doesn't get fast, and in some cases it stops clearing what was there before, and just draws over top of what was there before! How can I get this moving quickly? I've seen someone set a label image as the level and just MOVE the entire label, which I could do, but that seemed even SLOWER, even though it was really fast for him (am I doing something wrong there?) Here's my CURRENT graphics code (I've been changing it very fast!) private void Form1_Paint(object sender, System.Windows.Forms.PaintEventArgs e) { Graphics g=e.Graphics; //label1.Text=string.Format("{0}",playerspeed); //int beginingofdrawwidth = playerdata.Getlocationx()-(this.Width/2); //int endofdrawwidth = playerdata.Getlocationx()+(this.Width/2); //int beginingofdrawheight = playerdata.Getlocationy()-(this.Height/2); //int endofdrawheight = playerdata.Getlocationy()+(this.Height/2); //Obviously don't draw anything if the level doesn't exist yet //This is because at the moment it comes up with a blank level at startup. if (levelimage!=null) { //Grab the relevant chunk, and draw it! Bitmap background=new Bitmap(levelimage,this.Width,this.Height); using(Graphics b = Graphics.FromImage(background)) { Rectangle sourceRectangle = new Rectangle(playerdata.Getlocationx()-this.Width/2, playerdata.Getlocationy()-this.Width, this.Width, this.Height); b.DrawImage(levelimage,0,0,sourceRectangle,System.Drawing.GraphicsUnit.Pixel); } g.DrawImage(background,0,0); } // for (int x=0; x

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linkingfire22y ago
I'm afraid we've spent a lot more time on other things besides graphics, and I don't know how to blit the backbuffers. :-/ Right now I'm working with a groupBox and moving it, as it is smooth, and then drawing over that...
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scyphe66622y ago
Well, I've been coding C# for 8 weeks, had the final exam for C# yesterday, so I'm e novice ;) I've learned one thing though, using GDI+ in C# is not a good way to get smooth graphics. I'm looking into DirectX-stuff instead. But let me show you what I did in my project that I finished a few weeks ago (a game with some graphics and sound): private void SlotForm_Paint(object sender, System.Windows.Forms.PaintEventArgs e) { m_CPaint.Update(e.Graphics, m_CRandom.slot1, m_CRandom.slot2, m_CRandom.slot3); m_CGun.Draw(e.Graphics); m_CMoney.UpdateMoneyText(e.Graphics); m_CLogo.DrawLogo(e.Graphics); } the only thing I do in the Paint-event is the actual drawing, I don't create any new objects since I created them in the Form_Load. For instance, this is what m_CGun.Draw looks like: (paints one of two guns, one with the trigger pulled) public void Draw(Graphics clientDC) { if(m_bFired == true) <-- a bool keeping track if I pressed the mouse within a certain area. { clientDC.DrawImage(m_Pull2, m_Location.X, m_Location.Y) ; <-- draw bitmap m_Pull2 at x,y } else { clientDC.DrawImage(m_Pull1, m_Location.X, m_Location.Y) ; <-- same, but with the non-triggered gun! } } Since the object are already created and resides in the heap, I don't allocate new memory each paint. I'm not sure about what you're trying to do in your project though. I am guessing you're moving the graphics across the screen. In that case you'd be better off by having two backbuffers and blitting them to the active screen, ie. blit the backbuffer1 (the background) and then blit the correct area of backbuffer2 (the object) onto the main screen in succession. The timer was just an idea to make regular paintings, but if something is slower than the timer, it will be choppy.
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linkingfire22y ago
Ok, I have done the double buffering. That either causes it to flicker any way (just slow speed, I think), or prevents it from drawing say, or more accurately, it draws, but doesn't clear the screen from what was previously there! I have five classes. The ships(to be handled by a thread, they aren't in yet, other than the player, obviously), the shots (handled by a thread), the Definitions of what each component is (only used when creating a level, as it reads levels in a way that allows the designer to use whatever construction technique he wants, so long as he defines each type he uses.), the triggers(for in game events, such as the destruction of a building), and the pass class (I needed a reference type to say whether the shot class was waiting on the drawing class or not, so that if it does slow down, the shots don't travel the whole screen and never get drawn...). So are you saying: Timer_Tick(windows junk) { HandlePlayer(); Creategraphics(); this.Invalidate(); } Instead? I understand some of what you said, and I thank you. I'm not entirely a novice myself (I mean, I'm still a beginner, but I'm in class, etc, know the basics. No where close to knowing it, though), I do really well in class and I've coded before, but this is WAY beyond what we are doing in class, I'm doing this to challenge myself, but this is something that I just DON'T know how to solve. It's not some algorithm that I think I'm missing... Since I'm relying on the timer, how can I cause the graphics to be created in between, have two timers maybe? One is say, ten milliseconds before the other consistently, dictating the drawing, and the other is the drawing control? Would that work, is that what you are saying? So like: Timer1_Tick(windows) { HandlePlayer(); Creategraphics(); } Timer2_tick(windows) { this.Invalidate(); } Thanks though, I really appreciate your help! I know I can write hard to follow code (notice the commented out portions that were remnants of previous experiments in speed), and I know beginner's questions can be a bit niave, so thanks!
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scyphe66622y ago
Hmm.. I'd try two things (I'm a novice though): Enable double buffering, and add a timer that does this.invalidate() in a regular pace (50-100ms). And I'd lift out pretty much all the code and put it in a class. Creating objects and handling all sorts of things in the paint-event seems unnecessary and takes a lot of extra time. Essentially, you create a new bitmap every time the form is redrawn. "Bitmap background=new Bitmap(levelimage,this.Width,this.Height);" Making objects out of the bitmaps and other stuff, draw to the buffer and then call the Paint event would seem to be a bit more optimized. Enable doublebuffer - add the following code to your Form_Load method: this.SetStyle(ControlStyles.UserPaint, true); this.SetStyle(ControlStyles.DoubleBuffer, true); this.SetStyle(ControlStyles.AllPaintingInWmPaint, true); this.UpdateStyles();
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