patch_rasterize

Rasterization of a 2D triangulation

patch_rasterize Rasterization of a 2D triangulation
patch_rasterize rasterize a 2D triangulation into a image. The function
returns an image rasterizing the triangulation. This image is similar
to the one used for OpenGL's glSelectBuffer for fast "picking".

I = patch_rasterize(p) creates an image of size=max(p.vertices). If the
f-th triangle p.faces(f,:) contains the pixels at position (i,j) then
I(i,j)=f.

Once I has been computed, retrieving a the index of the triangle
containing the point (x,y) can be achieved by f = I( round(x), round(y) )

The function run without parameters executes Example 1.

Example 1:
clc, clear, close all;
% generate some data
P = gallery('uniformdata',[100 2],0);
DT = delaunayTriangulation(P);
p.faces = DT.ConnectivityList;
p.vertices = DT.Points * 300;
% rasterize it
I = patch_rasterize(p);
figure, hold on;
imagesc(I); axis image;
triplot(p.faces, p.vertices(:,1), p.vertices(:,2), 'color', 'white');

See also patch, triangulation,