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vector.triangle: (try to) avoid holes in neighbouring triangles

This commit is contained in:
HybridDog 2020-04-18 14:16:35 +02:00
parent bc08421e20
commit 6f2bc919db
2 changed files with 6 additions and 1 deletions
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1
README.txt
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@ -3,3 +3,4 @@ TODO:
* Figure out and implement 3D scanline search
* Add vector.hollowsphere, less positions than WorldEdit hollowsphere
* Add unit tests
* Use %a string format for vector.serialize so that it is reversible

6
init.lua
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@ -1041,6 +1041,10 @@ function funcs.triangle(pos1, pos2, pos3)
return (pos[1] - p1[1]) * (p2[2] - p1[2])
- (pos[2] - p1[2]) * (p2[1] - p1[1])
end
-- eps is used to prevend holes in neighbouring triangles
-- It should be smaller than the smallest possible barycentric value
-- FIXME: I'm not sure if it really does what it should.
local eps = 0.5 / math.max(p2[1] - p1[1], p2[2] - p1[2])
local a_all_inv = 1.0 / edgefunc(pos1_2d, pos2_2d, pos3_2d)
local step_k3 = - (pos2_2d[1] - pos1_2d[1]) * a_all_inv
local step_k1 = - (pos3_2d[1] - pos2_2d[1]) * a_all_inv
@ -1055,7 +1059,7 @@ function funcs.triangle(pos1, pos2, pos3)
local k1 = edgefunc(pos2_2d, pos3_2d, p) * a_all_inv
for _ = p1[2], p2[2] do
local k2 = 1 - k1 - k3
if k1 >= 0 and k2 >= 0 and k3 >= 0 then
if k1 >= -eps and k2 >= -eps and k3 >= -eps then
-- On triangle
local h = math.floor(k1 * pos1[dir] + k2 * pos2[dir] +
k3 * pos3[dir] + 0.5)