Custom controll flickers!

[venomation]

Ok I invalidated the panel on the Scroll event but it flickers allot when it move the scroll slider it just looks plain ugly ! Is there another way as its visual effects is the same as when I use "panel1.Refresh()" ? Thanks for your help anyway I apologize for my incompetence xD

[Luc Pattyn]

it is high time you describe your overall goal, and the set-up of your controls. How many panels (or other Controls) are there, what is their purpose and relationship? etc. :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

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[venomation]

My goal is to create a simple control that can render a 2 dimensional grid. Its inputs are (tilewidth,tileheight,rows,columns) and the idea is that it can somehow generate the images like a grid inside a panel which can be scrolled left,right, up and down. This should allow me to be able to create a grid that is larger than the form and scroll across it to see different tiles. The problem with the one I made so far (with your assistance) is that it flickers when I scroll, on the "Scroll" event of the panel I force it to "Invalidate()" but this seems to make It flicker. If I do not use "Invalidate" or "Refresh" in the Scroll event of the panel then it does not show the updated grid that is drawn in the Paint event in the panel.

[Luc Pattyn]

0. I'm not sure I understand the role of the images in said grid. Is this a board game? 1. You did not answer "How many panels (or other Controls) are there, what is their purpose and relationship?" 2. Whatever approach, while scrolling, the view will update; and you could then complain for it to be sluggish i.e. not tracking your scroll movements fast enough, or flickering which may (or may not) mean it is following your scroll movement too nervously. 3. From what you told, did you consider having a (large) DataGridView inside a (smaller) Panel, with Panel.AutoScroll=true? :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

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I only read formatted code with indentation, so please use PRE tags for code snippets.

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I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).

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[venomation]

0. It is going to be used for a basic 2D Map editor so that I can make levels for games in XNA easier. Each tile can have an image and various properties associated with it and as map sizes vary I could have one map at 50*50 tiles or another at 100*100 tiles (x,y) 1. The panel is the only control running,its part of a custom control that can be dragged and dropped from the toolbox, literally just a panel component with features to render the grid using the System.Draw. Its on a test form on its own, im testing it with a 100 * 100 tile grid at 32*32 width *height. 2. I have played with the speed of which it scrolls, it appears that even a very small change in its scroll values cause the panel to flicker due to it being Invalidated() on the "Scroll" event of the panel. 3. I dont know how a data-grid can help as this it visual drawing to the panel, im only drawing the grid to the panel as I need something that can scroll easily. Hope this helps and thanks ! :-D

[Luc Pattyn]

OK, I now have a better view on your app. Thanks. So I take it your entire UserControl is showing (part of) the gridded map, and has its AutoScroll set true. I did some experiments with a Form holding a small autoscroll Panel which holds a much larger panel, and that seems to scroll quite well. Maybe you still have something causing lots of CPU cycles getting wasted, but I don't recall having seen so in your latest Paint handler. Or is what you have shown only a simplified snippet, and some more expensive operations are also present? BTW: I have no XNA experience, however I somehow do expect someone to pop in and tell you now to use XNA for this editor too. :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

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I only read formatted code with indentation, so please use PRE tags for code snippets.

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I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).

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[venomation]

Well this is my latest code:

using System.Drawing;
using System.Windows.Forms;

namespace TileMapper.Presentation.Controls
{
public partial class MapRenderer : UserControl
{
private Point _tileBound;
private Point _rowsColumns;
private bool _initalized = false;
Rectangle[,] _renderBounds;
public MapRenderer()
{
InitializeComponent();
this.DoubleBuffered = true;

        // Activates double buffering 
        this.SetStyle(
           ControlStyles.OptimizedDoubleBuffer , true);
        this.UpdateStyles();
        panel1.HorizontalScroll.LargeChange = 1;


    }

    public void InitalizeGrid(int tileWidth, int tileHeight, int rows, int columns)
    {
        \_tileBound = new Point(tileWidth, tileHeight);
        \_rowsColumns = new Point(rows, columns);
        panel1.AutoScrollMinSize = new Size(\_tileBound.X \* \_rowsColumns.X, \_tileBound.Y \* \_rowsColumns.Y);
        \_initalized = true;
        \_pen = new Pen(Color.Black);
        \_tile = new Rectangle(0, 0, \_tileBound.X, \_tileBound.Y);
        \_im = Image.FromFile(@"C:/box.png");

        \_scrollValue = new Point(panel1.HorizontalScroll.Value, panel1.VerticalScroll.Value);

        \_renderBounds = new Rectangle\[\_tileBound.X, \_tileBound.Y\];

        for (int x = 0; x < \_tileBound.X; x++)
        {
            for (int y = 0; y < \_tileBound.Y; y++)
            {
                \_renderBounds\[x,y\] = new Rectangle(x \* \_tileBound.X
                   , y \* \_tileBound.Y, \_tileBound.X, \_tileBound.Y);
            }
        }
    }

    private Point \_scrollValue;

    Pen \_pen;
    Rectangle \_tile;
    private Image \_im;
    void DrawGrid(Graphics e, Rectangle bound)
    {
        int start = bound.X / \_tileBound.X;
        int end = bound.X/\_tileBound.X + bound.Width/\_tileBound.X;

        int startY = bound.Y / \_tileBound.Y;
        int endY = bound.Y + bound.Height/\_tileBound.Y;

        for (int x = start; x < end; x++)
        {
            for (int y = startY; y < endY; y++)
            {
               e.DrawImage(\_im, \_renderBounds\[x,y\], \_tile, GraphicsUnit.Pixel);
            }

        }

    }





    private void panel1\_Paint\_1(object sender, PaintEventArgs e)
    {
        if (\_initalized)
        {

[Luc Pattyn]

OK, the one thing I would simplify is the Graphics.DrawImage; when you specify both source and destination rectangles it will perform a scaling, whereas you probably don't need one. Drawing an entire bitmap at some location can be handled swiftly by Graphics.DrawImage(image, x, y); I am surprised your Panel is AutoScroll; your UserControl is too I assume (but I don't see that). As I said, (non-scrolling large) panel in small autoscrolling panel works fine for me, so I assume non-scrolling large panel in autoscrolling UserControl should too. :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

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I only read formatted code with indentation, so please use PRE tags for code snippets.

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I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).

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[venomation]

Thanks for your help I should be able to get it sorted ! :-D

[Luc Pattyn]

You're welcome. :)

Luc Pattyn [Forum Guidelines] [Why QA sucks] [My Articles]

---

I only read formatted code with indentation, so please use PRE tags for code snippets.

---

I'm not participating in frackin' Q&A, so if you want my opinion, ask away in a real forum (or on my profile page).

---