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OpenGL OpenGL draws Texture incorrect

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Hey Community :)

I´m trying to display a Quad with a texture, but it´s displaying just some pixels:

[media]http://imageshack.us/photo/my-images/21/errorkpl.jpg/[/media]

Here´s my code:

[code]int x1, x2, y1, y2;

public Form1()
{

x1 = 20;
x2 = 100;
y1 = 20;
y2 = 100;

InitializeComponent();
this.simpleOpenGlControl1.InitializeContexts();

const int XSIZE = 640;
const int YSIZE = 480;
Gl.glMatrixMode(Gl.GL_PROJECTION);
Gl.glLoadIdentity();
Gl.glOrtho(0, XSIZE, YSIZE, 0, 0, 1);
Gl.glMatrixMode(Gl.GL_MODELVIEW);

Gl.glEnable(Gl.GL_TEXTURE_2D);
Gl.glDisable(Gl.GL_DEPTH_TEST);
Gl.glClear(Gl.GL_COLOR_BUFFER_BIT);

// Texture

Bitmap b = new Bitmap(@"C:\Documents and Settings\MartDani\Desktop\menu_button.bmp");

Bitmap bitmap;
bitmap = (Bitmap)b.Clone(); // Input bitmap kopieren

int m_Width = bitmap.Width;
int m_Height = bitmap.Height;
int[] handle = new int[1];
Gl.glGenTextures(handle.Length, handle);

int m_Handle = handle[0];
handle = null;

Rectangle rect = new Rectangle(0, 0, m_Width, m_Height);
System.Drawing.Imaging.BitmapData bdata = bitmap.LockBits(rect, System.Drawing.Imaging.ImageLockMode.ReadOnly, bitmap.PixelFormat);

Gl.glBindTexture(Gl.GL_TEXTURE_2D, m_Handle);
Gl.glTexImage2D(Gl.GL_TEXTURE_2D, 0, Gl.GL_RGB, m_Width, m_Height, 0, Gl.GL_RGB, Gl.GL_UNSIGNED_BYTE, bdata.Scan0);
Gl.glTexParameteri(Gl.GL_TEXTURE_2D, Gl.GL_TEXTURE_MAG_FILTER, Gl.GL_LINEAR);
Gl.glTexParameteri(Gl.GL_TEXTURE_2D, Gl.GL_TEXTURE_MIN_FILTER, Gl.GL_LINEAR);

Gl.glEnable(Gl.GL_TEXTURE_2D);
Gl.glTexEnvf(Gl.GL_TEXTURE_ENV, Gl.GL_TEXTURE_ENV_MODE, Gl.GL_DECAL);
Gl.glColor3f(1f, 1f, 1f);
Gl.glBegin(Gl.GL_QUADS);

Gl.glTexCoord2f(x1, y1); Gl.glVertex2f(x1, y1);
Gl.glTexCoord2f(x1, y2); Gl.glVertex2f(x1, y2);
Gl.glTexCoord2f(x2, y2); Gl.glVertex2f(x2, y2);
Gl.glTexCoord2f(x2, y1); Gl.glVertex2f(x2, y1);

Gl.glEnd();
Gl.glDisable(Gl.GL_TEXTURE_2D);
bitmap.UnlockBits(bdata);
bitmap.Dispose();
//

// Point
Gl.glBegin(Gl.GL_POINTS);
Gl.glVertex2f(5, 5);
Gl.glEnd();
// /Point

// Quad
Gl.glEnable(Gl.GL_TEXTURE_2D);

Gl.glBegin(Gl.GL_QUADS);
Gl.glColor3f(1, 0, 0);
Gl.glVertex2f(x1 + 100, y1 + 100); Gl.glVertex2f(x2 + 100, y1 + 100); Gl.glVertex2f(x2 + 100, y2 + 100); Gl.glVertex2f(x1 + 100, y2 + 100);
Gl.glEnd();
// /Quad

}[/code]

I hope, anyone Can help me :)

Greetings from Germany

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[quote]
Gl.glTexCoord2f(x1, y1); Gl.glVertex2f(x1, y1);
Gl.glTexCoord2f(x1, y2); Gl.glVertex2f(x1, y2);
Gl.glTexCoord2f(x2, y2); Gl.glVertex2f(x2, y2);
Gl.glTexCoord2f(x2, y1); Gl.glVertex2f(x2, y1);
[/quote]

You don't want texcoord to be the same as the vertex coordinates. Textures range from 0 to 1. So by specifying it from 20 to 100 you're squishing and repeating your texture 80 times across the surface.

Try this instead:
[code]
Gl.glTexCoord2f(0, 0); Gl.glVertex2f(x1, y1);
Gl.glTexCoord2f(0, 1); Gl.glVertex2f(x1, y2);
Gl.glTexCoord2f(1, 1); Gl.glVertex2f(x2, y2);
Gl.glTexCoord2f(1, 0); Gl.glVertex2f(x2, y1);
[/code]

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Yes, that has done the job :D And i changed the Image-Format, so I choosed a .jpg (no alpha-channel), and now, it´s displaying it very good :D Thanks

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