OpenGL-使用非规范化的texcoords [英] OpenGL - Use non normalized texcoords

问题描述

默认情况下，OpenGL使用归一化的TexCoords，这意味着该值必须在0到1([0..1])之间. Vertex的常见实现必须看起来像这样:

By default, OpenGL uses normalized TexCoords, which mean the value must be between 0 and 1 ([0..1]). the common implementation of Vertex must be look something like this:

        // Common Implementation of Vertex
        Vertex v = new Vertex(
            // Position
            new Vector2(0f, 500f), 
            // 'Normalized' TexCoords [0..1]
            new Vector2(0f, 1f), 
            // Color of Vertex
            Color.White
        );

        // Or in immediate mode..
        // It's the same, we still need to specify between 0 and 1 ([0..1])
        GL.TexCoord2(1f, 0f);

但是，在OpenGL中是否可以使用非规范化的texcoord(因此以像素格式指定，这意味着该值必须在0到大小([0..size])之间?

However, is it possible to use non normalized texcoord (so it specified in pixel format, which mean the value must be between 0 and size ([0..size])) in OpenGL?

推荐答案

我仍然不知道为什么GL.Ortho(在MatrixMode.Texture中时)没有给我预期的结果.

I still can't figure out why GL.Ortho (while in MatrixMode.Texture) isn't give me intended result..

所以最后，我最终手动计算了矩阵:

So finally, I ended up with calculating matrix manually:

        // Initialize identity matrix
        Matrix4 matrix = new Matrix4
                         (1f, 0f, 0f, 0f,
                          0f, 1f, 0f, 0f,
                          0f, 0f, 1f, 0f,
                          0f, 0f, 0f, 1f);

        // Or use Matrix4.Identity (in OpenTK case), that should be equal(?)

        // Convert to normalized
        matrix[0, 0] = 1f / textureWidth;
        matrix[1, 1] = 1f / textureHeight;

        // Apply the matrix to texture matrix
        GL.MatrixMode(MatrixMode.Texture);
        GL.LoadMatrix(ref matrix);

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