diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,3 @@
+# 0
+
+* Split off from `codex`
diff --git a/LICENSE.md b/LICENSE.md
new file mode 100644
--- /dev/null
+++ b/LICENSE.md
@@ -0,0 +1,279 @@
+# License
+
+The Haskell code here is licensed under either
+ * Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)
+ * BSD 2-Clause license (https://opensource.org/licenses/BSD-2-Clause)
+at your option.
+
+The contained library `stb_rect_pack.h` is licensed under either
+ * MIT License
+ * Public Domain
+at your option.
+
+## ALTERNATIVE A: BSD 2-Clause License
+
+- Copyright 2019 Edward Kmett and Sean Chalmers
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+1. Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright
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+ documentation and/or other materials provided with the distribution.
+
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+POSSIBILITY OF SUCH DAMAGE.
+
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+
+# Licensing for `stb_rect_pack.h`
+
+This software is available under 2 licenses -- choose whichever you prefer.
+
+## ALTERNATIVE A - MIT License
+
+Copyright (c) 2017 Sean Barrett
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
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+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+
+## ALTERNATIVE B - Public Domain (www.unlicense.org)
+
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
+software, either in source code form or as a compiled binary, for any purpose,
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+In jurisdictions that recognize copyright laws, the author or authors of this
+software dedicate any and all copyright interest in the software to the public
+domain. We make this dedication for the benefit of the public at large and to
+the detriment of our heirs and successors. We intend this dedication to be an
+overt act of relinquishment in perpetuity of all present and future rights to
+this software under copyright law.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
--- /dev/null
+++ b/README.md
@@ -0,0 +1,16 @@
+atlas
+=====
+
+[](https://hackage.haskell.org/package/atlas) [](http://travis-ci.org/ekmett/atlas)
+
+This package provides 2D skyline rectangle packing, which can be useful for building texture atlases and the like.
+
+Contact Information
+-------------------
+
+Contributions and bug reports are welcome!
+
+Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net.
+
+-Edward Kmett
+
diff --git a/atlas.cabal b/atlas.cabal
new file mode 100644
--- /dev/null
+++ b/atlas.cabal
@@ -0,0 +1,60 @@
+cabal-version: 2.2
+name: atlas
+version: 0
+synopsis: Skyline rectangle packing
+homepage: https://github.com/ekmett/codex/tree/master/atlas#readme
+license: BSD-2-Clause OR Apache-2.0
+license-file: LICENSE.md
+author: Edward Kmett
+maintainer: Edward Kmett
+copyright: Copyright (c) 2019 Edward Kmett
+stability: experimental
+category: Graphics
+build-type: Simple
+description:
+ Skyline rectangle packing for font atlases and the like using @stb_rect_pack.h@
+extra-doc-files:
+ README.md,
+ CHANGELOG.md
+extra-source-files: cbits/stb_rect_pack.h
+
+source-repository head
+ type: git
+ location: https://github.com/ekmett/codex
+ subdir: atlas
+
+common base
+ default-language: Haskell2010
+ ghc-options:
+ -Wall -Wincomplete-uni-patterns -Wincomplete-record-updates
+ -Wredundant-constraints -Widentities -Wmissing-export-lists
+ build-depends:
+ base >= 4.11 && < 5,
+ primitive,
+ transformers
+
+library
+ import: base
+ hs-source-dirs: src
+ include-dirs: cbits
+ build-tool-depends: hsc2hs:hsc2hs
+ cc-options: -g -Wall
+ build-depends:
+ containers,
+ data-default,
+ inline-c,
+ lens,
+ template-haskell
+ exposed-modules:
+ Data.Atlas
+ Data.Atlas.Internal
+
+test-suite atlas-test
+ import: base
+ type: exitcode-stdio-1.0
+ hs-source-dirs: test
+ main-is: Spec.hs
+ build-depends:
+ atlas,
+ hspec
+
diff --git a/cbits/stb_rect_pack.h b/cbits/stb_rect_pack.h
new file mode 100644
--- /dev/null
+++ b/cbits/stb_rect_pack.h
@@ -0,0 +1,628 @@
+// stb_rect_pack.h - v1.00 - public domain - rectangle packing
+// Sean Barrett 2014
+//
+// Useful for e.g. packing rectangular textures into an atlas.
+// Does not do rotation.
+//
+// Not necessarily the awesomest packing method, but better than
+// the totally naive one in stb_truetype (which is primarily what
+// this is meant to replace).
+//
+// Has only had a few tests run, may have issues.
+//
+// More docs to come.
+//
+// No memory allocations; uses qsort() and assert() from stdlib.
+// Can override those by defining STBRP_SORT and STBRP_ASSERT.
+//
+// This library currently uses the Skyline Bottom-Left algorithm.
+//
+// Please note: better rectangle packers are welcome! Please
+// implement them to the same API, but with a different init
+// function.
+//
+// Credits
+//
+// Library
+// Sean Barrett
+// Minor features
+// Martins Mozeiko
+// github:IntellectualKitty
+//
+// Bugfixes / warning fixes
+// Jeremy Jaussaud
+// Fabian Giesen
+//
+// Version history:
+//
+// 1.00 (2019-02-25) avoid small space waste; gracefully fail too-wide rectangles
+// 0.99 (2019-02-07) warning fixes
+// 0.11 (2017-03-03) return packing success/fail result
+// 0.10 (2016-10-25) remove cast-away-const to avoid warnings
+// 0.09 (2016-08-27) fix compiler warnings
+// 0.08 (2015-09-13) really fix bug with empty rects (w=0 or h=0)
+// 0.07 (2015-09-13) fix bug with empty rects (w=0 or h=0)
+// 0.06 (2015-04-15) added STBRP_SORT to allow replacing qsort
+// 0.05: added STBRP_ASSERT to allow replacing assert
+// 0.04: fixed minor bug in STBRP_LARGE_RECTS support
+// 0.01: initial release
+//
+// LICENSE
+//
+// See end of file for license information.
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// INCLUDE SECTION
+//
+
+#ifndef STB_INCLUDE_STB_RECT_PACK_H
+#define STB_INCLUDE_STB_RECT_PACK_H
+
+#define STB_RECT_PACK_VERSION 1
+
+#ifdef STBRP_STATIC
+#define STBRP_DEF static
+#else
+#define STBRP_DEF extern
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct stbrp_context stbrp_context;
+typedef struct stbrp_node stbrp_node;
+typedef struct stbrp_rect stbrp_rect;
+
+#ifdef STBRP_LARGE_RECTS
+typedef int stbrp_coord;
+#else
+typedef unsigned short stbrp_coord;
+#endif
+
+STBRP_DEF int stbrp_pack_rects (stbrp_context *context, stbrp_rect *rects, int num_rects);
+// Assign packed locations to rectangles. The rectangles are of type
+// 'stbrp_rect' defined below, stored in the array 'rects', and there
+// are 'num_rects' many of them.
+//
+// Rectangles which are successfully packed have the 'was_packed' flag
+// set to a non-zero value and 'x' and 'y' store the minimum location
+// on each axis (i.e. bottom-left in cartesian coordinates, top-left
+// if you imagine y increasing downwards). Rectangles which do not fit
+// have the 'was_packed' flag set to 0.
+//
+// You should not try to access the 'rects' array from another thread
+// while this function is running, as the function temporarily reorders
+// the array while it executes.
+//
+// To pack into another rectangle, you need to call stbrp_init_target
+// again. To continue packing into the same rectangle, you can call
+// this function again. Calling this multiple times with multiple rect
+// arrays will probably produce worse packing results than calling it
+// a single time with the full rectangle array, but the option is
+// available.
+//
+// The function returns 1 if all of the rectangles were successfully
+// packed and 0 otherwise.
+
+struct stbrp_rect
+{
+ // reserved for your use:
+ int id;
+
+ // input:
+ stbrp_coord w, h;
+
+ // output:
+ stbrp_coord x, y;
+ int was_packed; // non-zero if valid packing
+
+}; // 16 bytes, nominally
+
+
+STBRP_DEF void stbrp_init_target (stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes);
+// Initialize a rectangle packer to:
+// pack a rectangle that is 'width' by 'height' in dimensions
+// using temporary storage provided by the array 'nodes', which is 'num_nodes' long
+//
+// You must call this function every time you start packing into a new target.
+//
+// There is no "shutdown" function. The 'nodes' memory must stay valid for
+// the following stbrp_pack_rects() call (or calls), but can be freed after
+// the call (or calls) finish.
+//
+// Note: to guarantee best results, either:
+// 1. make sure 'num_nodes' >= 'width'
+// or 2. call stbrp_allow_out_of_mem() defined below with 'allow_out_of_mem = 1'
+//
+// If you don't do either of the above things, widths will be quantized to multiples
+// of small integers to guarantee the algorithm doesn't run out of temporary storage.
+//
+// If you do #2, then the non-quantized algorithm will be used, but the algorithm
+// may run out of temporary storage and be unable to pack some rectangles.
+
+STBRP_DEF void stbrp_setup_allow_out_of_mem (stbrp_context *context, int allow_out_of_mem);
+// Optionally call this function after init but before doing any packing to
+// change the handling of the out-of-temp-memory scenario, described above.
+// If you call init again, this will be reset to the default (false).
+
+
+STBRP_DEF void stbrp_setup_heuristic (stbrp_context *context, int heuristic);
+// Optionally select which packing heuristic the library should use. Different
+// heuristics will produce better/worse results for different data sets.
+// If you call init again, this will be reset to the default.
+
+enum
+{
+ STBRP_HEURISTIC_Skyline_default=0,
+ STBRP_HEURISTIC_Skyline_BL_sortHeight = STBRP_HEURISTIC_Skyline_default,
+ STBRP_HEURISTIC_Skyline_BF_sortHeight
+};
+
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// the details of the following structures don't matter to you, but they must
+// be visible so you can handle the memory allocations for them
+
+struct stbrp_node
+{
+ stbrp_coord x,y;
+ stbrp_node *next;
+};
+
+struct stbrp_context
+{
+ int width;
+ int height;
+ int align;
+ int init_mode;
+ int heuristic;
+ int num_nodes;
+ stbrp_node *active_head;
+ stbrp_node *free_head;
+ stbrp_node extra[2]; // we allocate two extra nodes so optimal user-node-count is 'width' not 'width+2'
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
+
+//////////////////////////////////////////////////////////////////////////////
+//
+// IMPLEMENTATION SECTION
+//
+
+#ifdef STB_RECT_PACK_IMPLEMENTATION
+#ifndef STBRP_SORT
+#include
+#define STBRP_SORT qsort
+#endif
+
+#ifndef STBRP_ASSERT
+#include
+#define STBRP_ASSERT assert
+#endif
+
+#ifdef _MSC_VER
+#define STBRP__NOTUSED(v) (void)(v)
+#else
+#define STBRP__NOTUSED(v) (void)sizeof(v)
+#endif
+
+enum
+{
+ STBRP__INIT_skyline = 1
+};
+
+STBRP_DEF void stbrp_setup_heuristic(stbrp_context *context, int heuristic)
+{
+ switch (context->init_mode) {
+ case STBRP__INIT_skyline:
+ STBRP_ASSERT(heuristic == STBRP_HEURISTIC_Skyline_BL_sortHeight || heuristic == STBRP_HEURISTIC_Skyline_BF_sortHeight);
+ context->heuristic = heuristic;
+ break;
+ default:
+ STBRP_ASSERT(0);
+ }
+}
+
+STBRP_DEF void stbrp_setup_allow_out_of_mem(stbrp_context *context, int allow_out_of_mem)
+{
+ if (allow_out_of_mem)
+ // if it's ok to run out of memory, then don't bother aligning them;
+ // this gives better packing, but may fail due to OOM (even though
+ // the rectangles easily fit). @TODO a smarter approach would be to only
+ // quantize once we've hit OOM, then we could get rid of this parameter.
+ context->align = 1;
+ else {
+ // if it's not ok to run out of memory, then quantize the widths
+ // so that num_nodes is always enough nodes.
+ //
+ // I.e. num_nodes * align >= width
+ // align >= width / num_nodes
+ // align = ceil(width/num_nodes)
+
+ context->align = (context->width + context->num_nodes-1) / context->num_nodes;
+ }
+}
+
+STBRP_DEF void stbrp_init_target(stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes)
+{
+ int i;
+#ifndef STBRP_LARGE_RECTS
+ STBRP_ASSERT(width <= 0xffff && height <= 0xffff);
+#endif
+
+ for (i=0; i < num_nodes-1; ++i)
+ nodes[i].next = &nodes[i+1];
+ nodes[i].next = NULL;
+ context->init_mode = STBRP__INIT_skyline;
+ context->heuristic = STBRP_HEURISTIC_Skyline_default;
+ context->free_head = &nodes[0];
+ context->active_head = &context->extra[0];
+ context->width = width;
+ context->height = height;
+ context->num_nodes = num_nodes;
+ stbrp_setup_allow_out_of_mem(context, 0);
+
+ // node 0 is the full width, node 1 is the sentinel (lets us not store width explicitly)
+ context->extra[0].x = 0;
+ context->extra[0].y = 0;
+ context->extra[0].next = &context->extra[1];
+ context->extra[1].x = (stbrp_coord) width;
+#ifdef STBRP_LARGE_RECTS
+ context->extra[1].y = (1<<30);
+#else
+ context->extra[1].y = 65535;
+#endif
+ context->extra[1].next = NULL;
+}
+
+// find minimum y position if it starts at x1
+static int stbrp__skyline_find_min_y(stbrp_context *c, stbrp_node *first, int x0, int width, int *pwaste)
+{
+ stbrp_node *node = first;
+ int x1 = x0 + width;
+ int min_y, visited_width, waste_area;
+
+ STBRP__NOTUSED(c);
+
+ STBRP_ASSERT(first->x <= x0);
+
+ #if 0
+ // skip in case we're past the node
+ while (node->next->x <= x0)
+ ++node;
+ #else
+ STBRP_ASSERT(node->next->x > x0); // we ended up handling this in the caller for efficiency
+ #endif
+
+ STBRP_ASSERT(node->x <= x0);
+
+ min_y = 0;
+ waste_area = 0;
+ visited_width = 0;
+ while (node->x < x1) {
+ if (node->y > min_y) {
+ // raise min_y higher.
+ // we've accounted for all waste up to min_y,
+ // but we'll now add more waste for everything we've visted
+ waste_area += visited_width * (node->y - min_y);
+ min_y = node->y;
+ // the first time through, visited_width might be reduced
+ if (node->x < x0)
+ visited_width += node->next->x - x0;
+ else
+ visited_width += node->next->x - node->x;
+ } else {
+ // add waste area
+ int under_width = node->next->x - node->x;
+ if (under_width + visited_width > width)
+ under_width = width - visited_width;
+ waste_area += under_width * (min_y - node->y);
+ visited_width += under_width;
+ }
+ node = node->next;
+ }
+
+ *pwaste = waste_area;
+ return min_y;
+}
+
+typedef struct
+{
+ int x,y;
+ stbrp_node **prev_link;
+} stbrp__findresult;
+
+static stbrp__findresult stbrp__skyline_find_best_pos(stbrp_context *c, int width, int height)
+{
+ int best_waste = (1<<30), best_x, best_y = (1 << 30);
+ stbrp__findresult fr;
+ stbrp_node **prev, *node, *tail, **best = NULL;
+
+ // align to multiple of c->align
+ width = (width + c->align - 1);
+ width -= width % c->align;
+ STBRP_ASSERT(width % c->align == 0);
+
+ // if it can't possibly fit, bail immediately
+ if (width > c->width || height > c->height) {
+ fr.prev_link = NULL;
+ fr.x = fr.y = 0;
+ return fr;
+ }
+
+ node = c->active_head;
+ prev = &c->active_head;
+ while (node->x + width <= c->width) {
+ int y,waste;
+ y = stbrp__skyline_find_min_y(c, node, node->x, width, &waste);
+ if (c->heuristic == STBRP_HEURISTIC_Skyline_BL_sortHeight) { // actually just want to test BL
+ // bottom left
+ if (y < best_y) {
+ best_y = y;
+ best = prev;
+ }
+ } else {
+ // best-fit
+ if (y + height <= c->height) {
+ // can only use it if it first vertically
+ if (y < best_y || (y == best_y && waste < best_waste)) {
+ best_y = y;
+ best_waste = waste;
+ best = prev;
+ }
+ }
+ }
+ prev = &node->next;
+ node = node->next;
+ }
+
+ best_x = (best == NULL) ? 0 : (*best)->x;
+
+ // if doing best-fit (BF), we also have to try aligning right edge to each node position
+ //
+ // e.g, if fitting
+ //
+ // ____________________
+ // |____________________|
+ //
+ // into
+ //
+ // | |
+ // | ____________|
+ // |____________|
+ //
+ // then right-aligned reduces waste, but bottom-left BL is always chooses left-aligned
+ //
+ // This makes BF take about 2x the time
+
+ if (c->heuristic == STBRP_HEURISTIC_Skyline_BF_sortHeight) {
+ tail = c->active_head;
+ node = c->active_head;
+ prev = &c->active_head;
+ // find first node that's admissible
+ while (tail->x < width)
+ tail = tail->next;
+ while (tail) {
+ int xpos = tail->x - width;
+ int y,waste;
+ STBRP_ASSERT(xpos >= 0);
+ // find the left position that matches this
+ while (node->next->x <= xpos) {
+ prev = &node->next;
+ node = node->next;
+ }
+ STBRP_ASSERT(node->next->x > xpos && node->x <= xpos);
+ y = stbrp__skyline_find_min_y(c, node, xpos, width, &waste);
+ if (y + height <= c->height) {
+ if (y <= best_y) {
+ if (y < best_y || waste < best_waste || (waste==best_waste && xpos < best_x)) {
+ best_x = xpos;
+ STBRP_ASSERT(y <= best_y);
+ best_y = y;
+ best_waste = waste;
+ best = prev;
+ }
+ }
+ }
+ tail = tail->next;
+ }
+ }
+
+ fr.prev_link = best;
+ fr.x = best_x;
+ fr.y = best_y;
+ return fr;
+}
+
+static stbrp__findresult stbrp__skyline_pack_rectangle(stbrp_context *context, int width, int height)
+{
+ // find best position according to heuristic
+ stbrp__findresult res = stbrp__skyline_find_best_pos(context, width, height);
+ stbrp_node *node, *cur;
+
+ // bail if:
+ // 1. it failed
+ // 2. the best node doesn't fit (we don't always check this)
+ // 3. we're out of memory
+ if (res.prev_link == NULL || res.y + height > context->height || context->free_head == NULL) {
+ res.prev_link = NULL;
+ return res;
+ }
+
+ // on success, create new node
+ node = context->free_head;
+ node->x = (stbrp_coord) res.x;
+ node->y = (stbrp_coord) (res.y + height);
+
+ context->free_head = node->next;
+
+ // insert the new node into the right starting point, and
+ // let 'cur' point to the remaining nodes needing to be
+ // stiched back in
+
+ cur = *res.prev_link;
+ if (cur->x < res.x) {
+ // preserve the existing one, so start testing with the next one
+ stbrp_node *next = cur->next;
+ cur->next = node;
+ cur = next;
+ } else {
+ *res.prev_link = node;
+ }
+
+ // from here, traverse cur and free the nodes, until we get to one
+ // that shouldn't be freed
+ while (cur->next && cur->next->x <= res.x + width) {
+ stbrp_node *next = cur->next;
+ // move the current node to the free list
+ cur->next = context->free_head;
+ context->free_head = cur;
+ cur = next;
+ }
+
+ // stitch the list back in
+ node->next = cur;
+
+ if (cur->x < res.x + width)
+ cur->x = (stbrp_coord) (res.x + width);
+
+#ifdef _DEBUG
+ cur = context->active_head;
+ while (cur->x < context->width) {
+ STBRP_ASSERT(cur->x < cur->next->x);
+ cur = cur->next;
+ }
+ STBRP_ASSERT(cur->next == NULL);
+
+ {
+ int count=0;
+ cur = context->active_head;
+ while (cur) {
+ cur = cur->next;
+ ++count;
+ }
+ cur = context->free_head;
+ while (cur) {
+ cur = cur->next;
+ ++count;
+ }
+ STBRP_ASSERT(count == context->num_nodes+2);
+ }
+#endif
+
+ return res;
+}
+
+static int rect_height_compare(const void *a, const void *b)
+{
+ const stbrp_rect *p = (const stbrp_rect *) a;
+ const stbrp_rect *q = (const stbrp_rect *) b;
+ if (p->h > q->h)
+ return -1;
+ if (p->h < q->h)
+ return 1;
+ return (p->w > q->w) ? -1 : (p->w < q->w);
+}
+
+static int rect_original_order(const void *a, const void *b)
+{
+ const stbrp_rect *p = (const stbrp_rect *) a;
+ const stbrp_rect *q = (const stbrp_rect *) b;
+ return (p->was_packed < q->was_packed) ? -1 : (p->was_packed > q->was_packed);
+}
+
+#ifdef STBRP_LARGE_RECTS
+#define STBRP__MAXVAL 0xffffffff
+#else
+#define STBRP__MAXVAL 0xffff
+#endif
+
+STBRP_DEF int stbrp_pack_rects(stbrp_context *context, stbrp_rect *rects, int num_rects)
+{
+ int i, all_rects_packed = 1;
+
+ // we use the 'was_packed' field internally to allow sorting/unsorting
+ for (i=0; i < num_rects; ++i) {
+ rects[i].was_packed = i;
+ }
+
+ // sort according to heuristic
+ STBRP_SORT(rects, num_rects, sizeof(rects[0]), rect_height_compare);
+
+ for (i=0; i < num_rects; ++i) {
+ if (rects[i].w == 0 || rects[i].h == 0) {
+ rects[i].x = rects[i].y = 0; // empty rect needs no space
+ } else {
+ stbrp__findresult fr = stbrp__skyline_pack_rectangle(context, rects[i].w, rects[i].h);
+ if (fr.prev_link) {
+ rects[i].x = (stbrp_coord) fr.x;
+ rects[i].y = (stbrp_coord) fr.y;
+ } else {
+ rects[i].x = rects[i].y = STBRP__MAXVAL;
+ }
+ }
+ }
+
+ // unsort
+ STBRP_SORT(rects, num_rects, sizeof(rects[0]), rect_original_order);
+
+ // set was_packed flags and all_rects_packed status
+ for (i=0; i < num_rects; ++i) {
+ rects[i].was_packed = !(rects[i].x == STBRP__MAXVAL && rects[i].y == STBRP__MAXVAL);
+ if (!rects[i].was_packed)
+ all_rects_packed = 0;
+ }
+
+ // return the all_rects_packed status
+ return all_rects_packed;
+}
+#endif
+
+/*
+------------------------------------------------------------------------------
+This software is available under 2 licenses -- choose whichever you prefer.
+------------------------------------------------------------------------------
+ALTERNATIVE A - MIT License
+Copyright (c) 2017 Sean Barrett
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+of the Software, and to permit persons to whom the Software is furnished to do
+so, subject to the following conditions:
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+------------------------------------------------------------------------------
+ALTERNATIVE B - Public Domain (www.unlicense.org)
+This is free and unencumbered software released into the public domain.
+Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
+software, either in source code form or as a compiled binary, for any purpose,
+commercial or non-commercial, and by any means.
+In jurisdictions that recognize copyright laws, the author or authors of this
+software dedicate any and all copyright interest in the software to the public
+domain. We make this dedication for the benefit of the public at large and to
+the detriment of our heirs and successors. We intend this dedication to be an
+overt act of relinquishment in perpetuity of all present and future rights to
+this software under copyright law.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+------------------------------------------------------------------------------
+*/
diff --git a/src/Data/Atlas.hs b/src/Data/Atlas.hs
new file mode 100644
--- /dev/null
+++ b/src/Data/Atlas.hs
@@ -0,0 +1,130 @@
+{-# language TypeOperators #-}
+{-# language ScopedTypeVariables #-}
+{-# language UndecidableInstances #-}
+{-# language MultiParamTypeClasses #-}
+{-# language FlexibleInstances #-}
+{-# language TemplateHaskell #-}
+{-# language QuasiQuotes #-}
+{-# language ViewPatterns #-}
+{-# language BlockArguments #-}
+-- |
+-- Copyright : (c) 2019-2021 Edward Kmett
+-- License : BSD-2-Clause OR Apache-2.0
+-- Maintainer: Edward Kmett
+-- Stability : experimental
+-- Portability: non-portable
+--
+-- skyline packing using @stb_rect_pack.h@
+module Data.Atlas
+( Atlas
+, create
+, createExplicit
+, reset
+-- * Setup
+, Heuristic(..)
+, setHeuristic
+, setAllowOutOfMem
+-- * Using a context
+, Pt(..)
+, pack
+, pack1
+, packM
+) where
+
+import Control.Lens
+import Control.Monad
+import Control.Monad.Primitive
+import Control.Monad.Trans.State.Strict
+import Data.Atlas.Internal
+import Data.Maybe (fromMaybe)
+import Foreign.ForeignPtr
+import Foreign.Marshal.Alloc
+import Foreign.Ptr
+import GHC.Stack
+import qualified Language.C.Inline as C
+import qualified Language.C.Inline.Unsafe as CU
+
+C.context $ C.baseCtx <> C.fptrCtx <> atlasCtx
+C.verbatim "#define STB_RECT_PACK_IMPLEMENTATION"
+C.include "stb_rect_pack.h"
+
+-- | Create a packing context.
+
+create :: (HasCallStack, PrimMonad m) => Int -> Int -> m (Atlas (PrimState m))
+create w h = createExplicit w h Nothing
+
+-- | Initialization with an optional node count, when @node count < width@ is used this results in quantization unless
+-- 'setAllowOutOfMem' is enabled. When no value is supplied, it defaults to the width of the 'Atlas'.
+createExplicit :: HasCallStack => PrimMonad m => Int -> Int -> Maybe Int -> m (Atlas (PrimState m))
+createExplicit width@(fromIntegral -> w) height@(fromIntegral -> h) mn = withFrozenCallStack $ unsafeIOToPrim do
+ let nodes@(fromIntegral -> n) = fromMaybe width mn
+ unless (width < 0xffff && height < 0xffff) $ die $ "Atlas.new " ++ show width ++ " " ++ show height ++ ": atlas too large"
+ fp <- mallocForeignPtrBytes (sizeOfAtlas + sizeOfNode * nodes)
+ Atlas fp <$ [CU.block|void {
+ stbrp_context * p = $atlas:fp;
+ stbrp_init_target(p,$(int w),$(int h),(stbrp_node *)(p+1),$(int n));
+ }|]
+
+-- | Reinitialize an atlas with the same parameters
+reset :: PrimMonad m => Atlas (PrimState m) -> m ()
+reset atlas = unsafeIOToPrim
+ [CU.block| void {
+ stbrp_context * p = $atlas:atlas;
+ int heuristic = p->heuristic;
+ int align = p->align;
+ stbrp_init_target(p,p->width,p->height,(stbrp_node*)(p+1),p->num_nodes);
+ p->heuristic = heuristic;
+ p->align = align;
+ }|]
+
+setHeuristic :: PrimMonad m => Atlas (PrimState m) -> Heuristic -> m ()
+setHeuristic fp (heuristicId -> h) = unsafeIOToPrim [CU.block|void { stbrp_setup_heuristic($atlas:fp,$(int h)); }|]
+
+setAllowOutOfMem :: PrimMonad m => Atlas (PrimState m) -> Bool -> m ()
+setAllowOutOfMem fp (fromIntegral . fromEnum -> b) = unsafeIOToPrim [CU.block|void { stbrp_setup_allow_out_of_mem($atlas:fp,$(int b)); }|]
+
+pack
+ :: (PrimMonad m, Traversable f)
+ => Atlas (PrimState m) -- ^ The atlas you want to pack these rectangles into.
+ -> (a -> Pt) -- ^ for each item you want to pack, extract the size.
+ -> (Maybe Pt -> a -> b) -- ^ when some fail to pack this will be called, with
+ -- 'Just' a position for each that succeeded, and
+ -- 'Nothing' for any that it failed on. The successes
+ -- and failures may well be out of order.
+ -> (Pt -> a -> c) -- ^ when all succeed this will be called with each position.
+ -> f a -- ^ A container full of things that you'd like to pack into the atlas.
+ -> m (Either (f b) (f c)) -- ^ Either a mixture of successes and failures, or a successful pack.
+pack atlas f g h as = stToPrim $ packM atlas (pure . f) g h as
+
+packM
+ :: (PrimBase m, Traversable f)
+ => Atlas (PrimState m) -- ^ The 'Atlas' you want to pack these rectangles into.
+ -> (a -> m Pt) -- ^ for each item you want to pack, extract the size,
+ -- with effects in @m@
+ -> (Maybe Pt -> a -> b) -- ^ when some fail to pack this will be called, with
+ -- 'Just' a position for each that succeeded, and
+ -- 'Nothing' for any that it failed on. The successes
+ -- and failures may well be out of order.
+ -> (Pt -> a -> c) -- ^ when all succeed, this will be called with each position.
+ -> f a -- ^ A container full of things that you'd like to pack into the atlas.
+ -> m (Either (f b) (f c)) -- ^ 'Either' a mixture of successes and failures, or a successful pack.
+packM fc f g h as = unsafeIOToPrim do
+ let n = length as
+ let cn = fromIntegral n
+ allocaBytes (n*sizeOfRect) \ rs -> do
+ iforOf_ folded as \i a -> do
+ p <- unsafePrimToIO $ f a
+ pokeWH (plusPtr rs (i*sizeOfRect)) p
+ res <- [CU.exp|int { stbrp_pack_rects($atlas:fc,$(stbrp_rect *rs),$(int cn)) }|]
+ if res == 0
+ then Left <$> evalStateT (traverse (go peekMaybeXY g) as) rs -- partial
+ else Right <$> evalStateT (traverse (go peekXY h) as) rs -- all allocated
+ where
+ go :: (Ptr Rect -> IO u) -> (u -> a -> d) -> a -> StateT (Ptr Rect) IO d
+ go k gh a = StateT \p -> (\b -> (,) (gh b a) $! plusPtr p sizeOfRect) <$> k p
+ {-# inline go #-}
+
+-- | Add one rectangle to the 'Atlas'. Using 'pack' can yield significantly better
+-- packing than calling this one rectangle at a time.
+pack1 :: PrimMonad m => Atlas (PrimState m) -> Pt -> m (Maybe Pt)
+pack1 atlas p = stToPrim $ either runIdentity runIdentity <$> pack atlas id const (const . Just) (Identity p)
diff --git a/src/Data/Atlas/Internal.hsc b/src/Data/Atlas/Internal.hsc
new file mode 100644
--- /dev/null
+++ b/src/Data/Atlas/Internal.hsc
@@ -0,0 +1,184 @@
+{-# language BangPatterns #-}
+{-# language LambdaCase #-}
+{-# language DeriveLift #-}
+{-# language ViewPatterns #-}
+{-# language ImplicitParams #-}
+{-# language RecordWildCards #-}
+{-# language OverloadedStrings #-}
+{-# language ScopedTypeVariables #-}
+{-# language StandaloneDeriving #-}
+{-# language UndecidableInstances #-}
+{-# language MultiParamTypeClasses #-}
+{-# language StrictData #-}
+{-# language FunctionalDependencies #-}
+{-# language TemplateHaskell #-}
+{-# language MultiWayIf #-}
+{-# language FlexibleInstances #-}
+
+-- |
+-- Copyright : (c) 2019 Edward Kmett
+-- License : BSD-2-Clause OR Apache-2.0
+-- Maintainer: Edward Kmett
+-- Stability : experimental
+-- Portability: non-portable
+--
+-- Details of the implementation.
+--
+-- The contents of this module do not fall under the PVP. Use at your own risk.
+
+#ifndef HLINT
+#include "stb_rect_pack.h"
+#endif
+
+module Data.Atlas.Internal
+( Atlas(..)
+, AtlasContext
+, Coord
+, Rect
+, Node
+, heuristicId, Heuristic(..)
+, sizeOfAtlas
+, sizeOfNode
+, sizeOfRect
+, Pt(..)
+, peekWH, peekXY
+, pokeWH, peekMaybeXY
+, atlasCtx
+, die
+) where
+
+import Control.Exception
+import Control.Monad.IO.Class
+import Data.Coerce
+import Data.Default
+import Data.Functor ((<&>))
+import qualified Data.Map as Map
+import Data.Word
+import Data.Int
+import Foreign.C.Types
+import Foreign.ForeignPtr
+import Foreign.Ptr
+import Foreign.Storable
+import GHC.Arr
+import GHC.Exception
+import GHC.Stack
+import qualified Language.C.Inline as C
+import qualified Language.C.Inline.Context as C
+import qualified Language.C.Inline.HaskellIdentifier as C
+import qualified Language.C.Types as C
+import qualified Language.Haskell.TH as TH
+import qualified Language.Haskell.TH.Syntax as TH
+
+type Coord = Word16
+data Node
+data Rect
+data AtlasContext
+
+newtype Atlas s = Atlas (ForeignPtr AtlasContext) deriving (Eq,Ord,Show)
+
+die :: (MonadIO m, HasCallStack) => String -> m a
+die msg = liftIO $ throwIO (errorCallWithCallStackException msg ?callStack)
+
+getHsVariable :: HasCallStack => C.HaskellIdentifier -> TH.ExpQ
+getHsVariable s = TH.lookupValueName (C.unHaskellIdentifier s) >>= \ case
+ Nothing -> die $ "Cannot capture Haskell variable " ++ C.unHaskellIdentifier s ++ ", because it's not in scope."
+ Just hsName -> TH.varE hsName
+
+anti :: HasCallStack => C.Type C.CIdentifier -> TH.TypeQ -> TH.ExpQ -> C.SomeAntiQuoter
+anti cTy hsTyQ w = C.SomeAntiQuoter C.AntiQuoter
+ { C.aqParser = C.parseIdentifier <&> \hId -> (C.mangleHaskellIdentifier False hId, cTy, hId)
+ , C.aqMarshaller = \_ _ _ cId -> (,) <$> hsTyQ <*> [|$w (coerce $(getHsVariable cId))|]
+ }
+
+atlasCtx :: C.Context
+atlasCtx = mempty
+ { C.ctxTypesTable = Map.fromList
+ [ (C.TypeName "stbrp_context", [t|AtlasContext|])
+ , (C.TypeName "stbrp_rect", [t|Rect|])
+ ]
+ , C.ctxAntiQuoters = Map.fromList
+ [ ("atlas"
+ , anti
+ (C.Ptr [] $ C.TypeSpecifier mempty $ C.TypeName "stbrp_context")
+ [t|Ptr AtlasContext|]
+ [|withForeignPtr|]
+ )
+ ]
+ }
+
+data Heuristic
+ = BottomLeft -- ^ bottom-left sort-height
+ | BestFirst -- ^ best first sort-height
+ deriving (Eq,Ord,Show,Read,Enum,Ix,Bounded,TH.Lift)
+
+instance Default Heuristic where
+ def = BottomLeft
+ {-# inline def #-}
+
+-- | Use and cast back and forth to ints instead for more natural API?
+data Pt = Pt Int Int deriving (Eq,Ord,Show,Read,TH.Lift)
+
+instance Num Pt where
+ Pt a b + Pt c d = Pt (a + c) (b + d)
+ Pt a b - Pt c d = Pt (a - c) (b - d)
+ Pt a b * Pt c d = Pt (a * c) (b * d)
+ abs (Pt a b) = Pt (abs a) (abs b)
+ signum (Pt a b) = Pt (signum a) (signum b)
+ negate (Pt a b) = Pt (negate a) (negate b)
+ fromInteger n = Pt (fromInteger n) (fromInteger n)
+ {-# inline (+) #-}
+ {-# inline (-) #-}
+ {-# inline (*) #-}
+ {-# inline abs #-}
+ {-# inline signum #-}
+ {-# inline negate #-}
+ {-# inline fromInteger #-}
+
+#ifndef HLINT
+
+heuristicId :: Heuristic -> CInt
+heuristicId BottomLeft = #const STBRP_HEURISTIC_Skyline_BL_sortHeight
+heuristicId BestFirst = #const STBRP_HEURISTIC_Skyline_BF_sortHeight
+{-# inline heuristicId #-}
+
+sizeOfAtlas :: Int
+sizeOfAtlas = #size stbrp_context
+{-# inline sizeOfAtlas #-}
+
+sizeOfNode :: Int
+sizeOfNode = #size stbrp_node
+{-# inline sizeOfNode #-}
+
+sizeOfRect :: Int
+sizeOfRect = #size stbrp_rect
+{-# inline sizeOfRect #-}
+
+peekWH :: Ptr Rect -> IO Pt
+peekWH p = (\(w :: Coord) (h :: Coord) -> Pt (fromIntegral w) (fromIntegral h))
+ <$> (#peek stbrp_rect, w) p
+ <*> (#peek stbrp_rect, h) p
+{-# inline peekWH #-}
+
+pokeWH :: Ptr Rect -> Pt -> IO ()
+pokeWH p (Pt w h) = do
+ (#poke stbrp_rect, id) p (0 :: Int32)
+ (#poke stbrp_rect, x) p (0 :: Coord)
+ (#poke stbrp_rect, y) p (0 :: Coord)
+ (#poke stbrp_rect, w) p (fromIntegral w :: Coord)
+ (#poke stbrp_rect, h) p (fromIntegral h :: Coord)
+ (#poke stbrp_rect, was_packed) p (0 :: Int32)
+{-# inline pokeWH #-}
+
+peekXY :: Ptr Rect -> IO Pt
+peekXY p = (\(w :: Coord) (h :: Coord) -> Pt (fromIntegral w) (fromIntegral h))
+ <$> (#peek stbrp_rect, x) p
+ <*> (#peek stbrp_rect, y) p
+{-# inline peekXY #-}
+
+peekMaybeXY :: Ptr Rect -> IO (Maybe Pt)
+peekMaybeXY p = (#peek stbrp_rect, was_packed) p >>= \case
+ (0 :: Int32) -> pure Nothing
+ _ -> Just <$> peekXY p
+{-# inline peekMaybeXY #-}
+
+#endif
diff --git a/test/Spec.hs b/test/Spec.hs
new file mode 100644
--- /dev/null
+++ b/test/Spec.hs
@@ -0,0 +1,26 @@
+module Main
+( main
+) where
+
+import Control.Monad.Primitive
+import Control.Monad.ST
+import Data.Atlas
+import Test.Hspec
+
+harnessM :: PrimBase m => Int -> Int -> [Pt] -> m (Either [Maybe Pt] [Pt])
+harnessM w h xs = do
+ ctx <- create w h
+ pack ctx id const const xs
+
+harness :: Int -> Int -> [Pt] -> Either [Maybe Pt] [Pt]
+harness w h xs = runST $ harnessM w h xs
+
+main :: IO ()
+main = hspec $
+ describe "Data.Atlas" $ do
+ it "can fill the packing region" $
+ harness 100 100 [Pt 50 50, Pt 50 50, Pt 50 50, Pt 50 50] `shouldBe` Right [Pt 0 0,Pt 50 0,Pt 0 50,Pt 50 50]
+ it "can run in IO" $
+ harnessM 100 100 [Pt 50 50, Pt 50 50, Pt 50 50, Pt 50 50] `shouldReturn` Right [Pt 0 0,Pt 50 0,Pt 0 50,Pt 50 50]
+ it "can be setup" $
+ (do ctx <- create 10 10; setHeuristic ctx BestFirst) `shouldReturn` ()