| // stb_rect_pack.h - v0.11 - 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 |
| // |
| // Version history: |
| // |
| // 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 <stdlib.h> |
| #define STBRP_SORT qsort |
| #endif |
| |
| #ifndef STBRP_ASSERT |
| #include <assert.h> |
| #define STBRP_ASSERT assert |
| #endif |
| |
| #ifdef _MSC_VER |
| #define STBRP__NOTUSED(v) (void)(v) |
| #define STBRP__CDECL __cdecl |
| #else |
| #define STBRP__NOTUSED(v) (void)sizeof(v) |
| #define STBRP__CDECL |
| #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); |
| |
| 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 STBRP__CDECL 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 STBRP__CDECL 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; |
| #ifndef STBRP_LARGE_RECTS |
| STBRP_ASSERT(rects[i].w <= 0xffff && rects[i].h <= 0xffff); |
| #endif |
| } |
| |
| // 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. |
| ------------------------------------------------------------------------------ |
| */ |