penpot/frontend/src/app/util/geom/grid.cljs
2021-04-12 16:49:43 +02:00

113 lines
4.9 KiB
Clojure

;; This Source Code Form is subject to the terms of the Mozilla Public
;; License, v. 2.0. If a copy of the MPL was not distributed with this
;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
;;
;; Copyright (c) UXBOX Labs SL
(ns app.util.geom.grid
(:require
[app.common.math :as mth]
[app.common.geom.point :as gpt]))
(def ^:private default-items 12)
(defn calculate-default-item-length
"Calculates the item-length so the default number of items fits inside the frame-length"
[frame-length margin gutter]
(/ (- frame-length (+ margin (- margin gutter)) (* gutter default-items)) default-items))
(defn calculate-size
"Calculates the number of rows/columns given the other grid parameters"
[frame-length item-length margin gutter]
(let [item-length (or item-length (calculate-default-item-length frame-length margin gutter))
frame-length-no-margins (- frame-length (+ margin (- margin gutter)))]
(mth/floor (/ frame-length-no-margins (+ item-length gutter)))))
(defn- calculate-column-grid
[{:keys [width height x y] :as frame} {:keys [size gutter margin item-length type] :as params}]
(let [size (if (number? size) size (calculate-size width item-length margin gutter))
parts (/ width size)
item-width (min (or item-length ##Inf) (+ parts (- gutter) (/ gutter size) (- (/ (* margin 2) size))))
item-height height
initial-offset (case type
:right (- width (* item-width size) (* gutter (dec size)) margin)
:center (/ (- width (* item-width size) (* gutter (dec size))) 2)
margin)
gutter (if (= :stretch type) (/ (- width (* item-width size) (* margin 2)) (dec size)) gutter)
next-x (fn [cur-val] (+ initial-offset x (* (+ item-width gutter) cur-val)))
next-y (fn [cur-val] y)]
[size item-width item-height next-x next-y]))
(defn- calculate-row-grid
[{:keys [width height x y] :as frame} {:keys [size gutter margin item-length type] :as params}]
(let [size (if (number? size) size (calculate-size height item-length margin gutter))
parts (/ height size)
item-width width
item-height (min (or item-length ##Inf) (+ parts (- gutter) (/ gutter size) (- (/ (* margin 2) size))))
initial-offset (case type
:right (- height (* item-height size) (* gutter (dec size)) margin)
:center (/ (- height (* item-height size) (* gutter (dec size))) 2)
margin)
gutter (if (= :stretch type) (/ (- height (* item-height size) (* margin 2)) (dec size)) gutter)
next-x (fn [cur-val] x)
next-y (fn [cur-val] (+ initial-offset y (* (+ item-height gutter) cur-val)))]
[size item-width item-height next-x next-y]))
(defn- calculate-square-grid
[{:keys [width height x y] :as frame} {:keys [size] :as params}]
(let [col-size (quot width size)
row-size (quot height size)
as-row-col (fn [value] [(quot value col-size) (rem value col-size)])
next-x (fn [cur-val]
(let [[_ col] (as-row-col cur-val)] (+ x (* col size))))
next-y (fn [cur-val]
(let [[row _] (as-row-col cur-val)] (+ y (* row size))))]
[(* col-size row-size) size size next-x next-y]))
(defn grid-areas
"Given a frame and the grid parameters returns the areas defined on the grid"
[frame grid]
(let [grid-fn (case (-> grid :type)
:column calculate-column-grid
:row calculate-row-grid
:square calculate-square-grid)
[num-items item-width item-height next-x next-y] (grid-fn frame (-> grid :params))]
(->>
(range 0 num-items)
(map #(hash-map :x (next-x %)
:y (next-y %)
:width item-width
:height item-height)))))
(defn grid-area-points
[{:keys [x y width height]}]
[(gpt/point x y)
(gpt/point (+ x width) y)
(gpt/point (+ x width) (+ y height))
(gpt/point x (+ y height))])
(defn grid-snap-points
"Returns the snap points for a given grid"
([shape coord] (mapcat #(grid-snap-points shape % coord) (:grids shape)))
([shape {:keys [type display params] :as grid} coord]
(when (:display grid)
(case type
:square
(let [{:keys [x y width height]} shape
size (-> params :size)]
(when (> size 0)
(if (= coord :x)
(mapcat #(vector (gpt/point (+ x %) y)
(gpt/point (+ x %) (+ y height))) (range size width size))
(mapcat #(vector (gpt/point x (+ y %))
(gpt/point (+ x width) (+ y %))) (range size height size)))))
:column
(when (= coord :x)
(->> (grid-areas shape grid)
(mapcat grid-area-points)))
:row
(when (= coord :y)
(->> (grid-areas shape grid)
(mapcat grid-area-points)))))))