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feuforeve.v4
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Change a few things in the island generator (notably : altitude generation, rainfall generation). Fix a few errors in the river drawing algorithm.

This commit is contained in:
Feufochmar 2020-12-27 01:09:52 +01:00
parent 9e4f49ab04
commit 43c66e1a3c
1 changed files with 80 additions and 32 deletions
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112
src/generators/island.rkt
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@ -23,22 +23,55 @@
(define cells (island-cells island))
(define size (min (2d-array-width cells) (2d-array-height cells)))
(define half-size (/ size 2))
(define noise-size (floor (/ size 12)))
(define noise-size (floor (/ size 15)))
(define ns (make-noise 2 noise-size))
(define (block i n) (* n (quotient i n)))
(define (on-border? i j)
(or (< i 5)
(< j 5)
(< (- (2d-array-width cells) i) 5)
(< (- (2d-array-height cells) j) 5)))
(2d-array-for-each/indexes
(island-cells island)
(lambda (cell i j)
(set-cell-altitude!
cell
(* 7
(+ -200
(* 400 (* (sin (/ (* pi i) size)) (sin (/ (* pi j) size))))
(* -100 (+ (expt (- i half-size) 2) (expt (- j half-size) 2)) (/ 2 (* size size)))
(* 200 (noise-gradient-value ns i j))
(* 25 (noise-value ns (block i 3) (block j 3)))
(* 25 (noise-value ns (block i 1) (block j 1)))
)))))
(cond
((on-border? i j) -700)
(#t
(* 200
(+ -7
(* 14 (* (sin (/ (* pi i) size)) (sin (/ (* pi j) size))))
(* -4 (+ (expt (- i half-size) 2) (expt (- j half-size) 2)) (/ 2 (* size size)))
(* 4 (noise-gradient-fractal-value ns 6 0.80 i j))
(* 2 (noise-gradient-value ns i j))
(* 1 (noise-value ns i j))
)))))))
; Add a temporary sea biome to remove the inland depressions
(2d-array-flood-map!
(island-cells island)
0 0
(lambda (cell)
(set-cell-biome! cell 'sea)
cell)
(lambda (init-cell visited-cell)
(and (not (cell-biome visited-cell))
(<= (cell-altitude visited-cell) 0)))
)
; Update the altitude to remove inland depressions
(2d-array-for-each
(island-cells island)
(lambda (cell)
(define alt (cell-altitude cell))
(when (and (not (eq? (cell-biome cell) 'sea))
(> 0 alt))
(set-cell-altitude!
cell
(- 0 alt)))))
; Remove the sea biome
(2d-array-for-each
(island-cells island)
(lambda (cell)
(set-cell-biome! cell #f)))
)
; Island generation, step 2: erosion pass
@ -279,7 +312,7 @@
pos-queue
(cdr pos+wind)))
distances-to-sea
'(888 1515 2121)
'(1919 1313 777)
(list
(pos+winds dominant-wind width height #t #f #f #t #f) ; M + AO
(pos+winds dominant-wind width height #f #t #f #f #t) ; A + O
@ -296,9 +329,9 @@
(+ ret (* weight (max 0 (/ (- max-dist dist) max-dist)))))
0
dists
'(175 75 50)
'(75 125 250))
(* alt 1/60)
'(100 75 75)
'(200 140 80))
(sqrt (* alt alt 1/100000))
(* -50 temp 1/50)
)))
; Update island
@ -427,7 +460,7 @@
(ni i)
(nj j)
(next-points+altitude (list)))
(when (< 0 iter)
(when (and (< 0 iter) (island-is-inside? island ni nj))
; set the lake biome on the cell
(set-cell-biome! (island-get-cell island ni nj) 'lake)
; Reset the river count of the cell
@ -442,14 +475,15 @@
(filter
(lambda (x)
(and
(island-is-inside? island (caar x) (cdar x))
(cdr x)
(not (eq? 'lake (island-biome island (caar x) (cdar x))))))
(map
(lambda (x)
(define nni (+ ni (car x)))
(define nnj (+ nj (cdr x)))
(cons (point nni nnj)
(island-altitude island nni nnj)))
(define nnalt (and (island-is-inside? island nni nnj)
(island-altitude island nni nnj)))
(cons (point nni nnj) nnalt))
river-directions)))
(lambda (x y)
(< (cdr x) (cdr y)))))
@ -488,6 +522,26 @@
; Island generation, step 8: add biomes
(define (island-set-biome! island)
; Fix lake touching sea by changing them to sea
; Change sea to lake
(2d-array-flood-map!
(island-cells island)
0 0
(lambda (cell)
(set-cell-biome! cell 'lake)
cell)
(lambda (init-cell visited-cell)
(eq? (cell-biome visited-cell) 'sea)))
; Change lake to sea
(2d-array-flood-map!
(island-cells island)
0 0
(lambda (cell)
(set-cell-biome! cell 'sea)
cell)
(lambda (init-cell visited-cell)
(eq? (cell-biome visited-cell) 'lake)))
; Compute the other biomes
(2d-array-for-each
(island-cells island)
(lambda (cell)
@ -564,19 +618,13 @@
(displayln "Computation of centers")
; random centers
(set-island-voronoi-centers! island
; Remove points located in sea and lakes
(filter
(lambda (x)
(define biome (island-biome island (car x) (cdr x)))
(and (not (eq? 'sea biome))
(not (eq? 'lake biome))))
; remove identical points
(remove-duplicates
; build the list: each point is randomly choosen
(build-list
(ceiling (* width height 1/25)) ; number of points: island-width/25 * island-height/25
(lambda (i)
(point (random width) (random height))))))))
; remove identical points
(remove-duplicates
; build the list: each point is randomly choosen
(build-list
(ceiling (* width height 1/25)) ; number of points: island-width/25 * island-height/25
(lambda (i)
(point (random width) (random height)))))))
; relax twice the points : recompute the voronoi centers from each voronoi cell
(time
(displayln "Relax centers")
@ -1033,7 +1081,7 @@
(define (island-generate size)
(define island (make-island size size))
(time
(displayln "Add Island")
(displayln "Add Altitude")
(island-set-altitude! island))
(time
(displayln "Add Erosion")