C# OpenGL 绘制拉伸(stretch)的二维纹理(不调整大小!)

Question

我正在尝试从这样的纹理中绘制一个按钮: 并通过这种方式做到这一点:

    //sWidth, sHeight - stretched size.
    Size mySize = TheSprite.MyTexture.TextureSize;
    OpenGL.glBindTexture(OpenGL.TextureTarget.Texture2D, TheSprite.MyTexture.MyTextureID);
    OpenGL.glBegin(OpenGL.BeginMode.Quads);
    double x = (double)TheDestination.Left;
    double y = (double)TheDestination.Top;
    double s = (double)(TheSprite.MyLocation.Left + TheSource.Left) / (double)mySize.Width + sWidth;
    double t = (double)(TheSprite.MyLocation.Top + TheSource.Top) / (double)mySize.Height + sHeight;
    double x2 = (double)TheDestination.Right + sWidth;
    double s2 = (double)(TheSprite.MyLocation.Left + TheSource.Right) / (double)mySize.Width + sWidth;
    double y2 = (double)TheDestination.Bottom + sHeight;
    double t2 = (double)(TheSprite.MyLocation.Top + TheSource.Bottom) / (double)mySize.Height + sHeight;

    OpenGL.glColor4(TheModulation);

    OpenGL.glTexCoord2d(s, t2);
    OpenGL.glVertex2d(x, y2);
    OpenGL.glTexCoord2d(s, t);
    OpenGL.glVertex2d(x, y);
    OpenGL.glTexCoord2d(s2, t);
    OpenGL.glVertex2d(x2, y);
    OpenGL.glTexCoord2d(s2, t2);
    OpenGL.glVertex2d(x2, y2);
    OpenGL.glEnd();

但就我而言，它看起来像这样:

而不是像这样的东西(相同的纹理):

在我的情况下，我应该如何绘制它以使其拉伸(stretch)而不是调整大小？

Answer 1

在这段代码中

OpenGL.glTexCoord2d(s, t2);
OpenGL.glVertex2d(x, y2);
OpenGL.glTexCoord2d(s, t);
OpenGL.glVertex2d(x, y);
OpenGL.glTexCoord2d(s2, t);
OpenGL.glVertex2d(x2, y);
OpenGL.glTexCoord2d(s2, t2);
OpenGL.glVertex2d(x2, y2);

您正在将纹理的角映射到按钮的角，如下所示:

由于您的纹理是正方形而按钮是矩形，因此纹理会水平拉伸(stretch)以适应按钮的宽度。如果你不希望黄色框在按钮的两侧被水平拉伸(stretch)，你需要在映射纹理时使用额外的点，以便只水平拉伸(stretch)它的中间部分(点 2-3-6-7 ).像这样: