#include "stb_rect_pack.h" #define STB_RECT_PACK_IMPLEMENTATION ////////////////////////////////////////////////////////////////////////////// // // 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); 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. 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