Hi,

I have a texture that I am able to display on a 2D square (easy). I want also to stretch that texture on a custom 2D polygon in order to fill it:
- Without losing pixels in the process (yes, the texture *will* be distorted and this is what I need)
- Without converting the texture (I need to display the same texture on a square and on a custom polygon at the same time)

Example picture of what I want to achieve:

I can't seem to find how to do this with OpenGL. Can it be done with shaders only? Any other ideas?

Thanks for all your input!

First, thanks for your answers!

Currently, I create the following VBO square with 2 triangles:


GLfloat vertices[] = {


-1.0, -1.0,
-1.0, 1.0,
1.0, -1.0,
1.0, 1.0
};

glGenBuffers(1, &vbo);
glBindBuffer(GL_ARRAY_BUFFER, vbo);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);



Then I create my texture data coords:

GLfloat texcoords[] = {



0.0, 0.0,
0.0, 1.0,
1.0, 0.0,
1.0, 1.0,
};
glGenBuffers(1, &vbo_texcoords);
glBindBuffer(GL_ARRAY_BUFFER, vbo_texcoords);
glBufferData(GL_ARRAY_BUFFER, sizeof(texcoords), texcoords, GL_STATIC_DRAW);

When I render, everything looks fine (the weird texture is actual data rendered to a 2d buffer):




Now I add vertexes and bend them to create another shape:


GLfloat vertices[] = {
-1.0, -0.5,
-0.2, 1.0,
-0.5, -1.0,
-0.1, 0.9,
0.5, -1.0,
0.1, 0.9,
1.0, -0.5,
0.2, 1.0,
};


GLfloat cube_texcoords[] = {
0.00, 0.0,
0.00, 1.0,
1.0/3.0, 0.0,
1.0/3.0, 1.0,
2.0/3.0, 0.0,
2.0/3.0, 1.0,
1.00, 0.0,
1.00, 1.0,

};

Result is not that ok (purple lines added in paint):


Note how the texture orientation is wrong in the smaller triangles. I render the shape using GL_TRIANGLE_STRIP. The order of the vertexes seems fine though. What went wrong?

In the end , what I'd like to achieve is exactly this: http://vimeo.com/38715344

Note how the shape (the video in this case -- on my side, it's a 2D buffer with rendered data) is distorted without clipping of the actual texture.

Thanks!