v3-rc2: Surface plot of f(x,y), with colormap in shader Computes the plot of a function $z=f(x,y)$ of two parameters. Draw the surface, grid wireframe, and cloud of points, each separately toggleable from UI. Heatmap of the function is not available for now. The compute kernel (be it on CPU or GPU) rescales $z$ values to be in the [0.0, 1.0] range (assuming given range; some of values fall outside it, to show how colormap handles such values). The function to draw is hardcoded in plot2d_common.hpp as `func(x,y)`, and cannot be changed at runtime. The min-max rescaling is implemented by `rescaledValue()`. The colormap code is embedded in the fragment shader, as `colormap()` function in the 'glsl/plot2d.vert' shader. Simple grayscale colormap (`vec4(x, x, x, 1.0)`) is used, with overflow marking (blue, or vec4(0,0,1,1), for values smaller than expected minimum value, and red, or vec4(1,0,0,1) for values above expected maximum).