Draws a convex polygon using the current source material to fill / texture with according to the texture coordinates passed.
true then the color will be changed for each vertex using the value specified in the color member of
TextureVertex. This can be used for example to make the texture fade out by
setting the alpha value of the color.
All of the texture coordinates must be in the range [0,1] and repeating the texture is not supported.
Because of the way this function is implemented it will currently only work if either the texture is not sliced or the backend is not OpenGL ES and the minifying and magnifying functions are both set to COGL_MATERIAL_FILTER_NEAREST.
An array of TextureVertex structs
The length of the vertices array