From b09f8186dcb7003774f07c99ab013fb6537bcf22 Mon Sep 17 00:00:00 2001 From: Sean Barrett Date: Mon, 24 Nov 2014 16:06:46 -0800 Subject: [PATCH 1/5] non-working rectangle packer --- stb_rect_pack.h | 402 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 402 insertions(+) create mode 100644 stb_rect_pack.h diff --git a/stb_rect_pack.h b/stb_rect_pack.h new file mode 100644 index 0000000..5800420 --- /dev/null +++ b/stb_rect_pack.h @@ -0,0 +1,402 @@ +// stb_rect_pack.h - v0.01 - public domain - rectangle packing +// +// Useful for e.g. packing rectangular textures into an atlas. +// +// By Sean Barrett and Ryan Gordon +// +// 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. Contact me for details of how to set up the +// heuristic enums and suchlike (as the code currently isn't +// designed to do that correctly internally). +// + +#ifndef STB_INCLUDE_STB_RECT_PACK_H +#define STB_INCLUDE_STB_RECT_PACK_H + +#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; + +enum +{ + STBRP_HEURISTIC_Skyline_default=0, + STBRP_HEURISTIC_Skyline_BL_sortHeight = STBRP_HEURISTIC_Skyline_default, + STBRP_HEURISTIC_Skyline_BF_sortHeight, +}; + +STBRP_DEF void stbrp_init_packer (stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes); +STBRP_DEF void stbrp_allow_oom (stbrp_context *context, int allow_out_of_mem); +STBRP_DEF void stbrp_set_heuristic(stbrp_context *context, int heuristic); +STBRP_DEF void stbrp_pack_rects (stbrp_context *context, stbrp_rect *rects, int num_rects); + +struct stbrp_rect +{ + // reserved for your use: + int id; + + // input: + unsigned short w, h; + + // output: + unsigned short x, y; + int was_packed; // non-zero if valid packing +}; // 16 bytes, nominally + +// the details of the following structures don't matter to you, but they must +// be visible so you can manage the memory allocations for them +struct stbrp_node +{ + unsigned short 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 user only needs to create 'width' for correctness, not width+1 +}; + +#ifdef __cplusplus +} +#endif + +#endif + + + +#ifdef STB_RECT_PACK_IMPLEMENTATION +#include + +enum +{ + STBRP__INIT_skyline = 1, +}; + +STBRP_DEF void stbrp_set_heuristic(stbrp_context *context, int heuristic) +{ + switch (context->init_mode) { + case STBRP__INIT_skyline: + assert(heuristic == STBRP_HEURISTIC_Skyline_BL_sortHeight || heuristic == STBRP_HEURISTIC_Skyline_BF_sortHeight); + break; + default: + assert(0); + } +} + +STBRP_DEF void stbrp_allow_oom(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_packer(stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes) +{ + int i; + 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->num_nodes = num_nodes; + stbrp_allow_oom(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 = width; + context->extra[1].y = 65535; + context->extra[2].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; + assert(first->x <= x0); + + #if 0 + // skip in case we're past the node + while (node->next->x <= x0) + ++node; + #else + assert(node->next->x > x0); // we ended up handling this in the caller for efficiency + #endif + + 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 ad more waste for everything we've visted + waste_area += visited_width * (node->y - min_y); + min_y = node->y; + } 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 += node->next->x - node->x; // adds too much the last time, but that's never used + node = node->next; + } + + *pwaste = waste_area; + return min_y; +} + +typedef struct +{ + int x,y; + stbrp_node **prev_link; +} stbrp__findresult; + +#define STBRP__HUGE_Y (1<<30) + +static stbrp__findresult stbrp__skyline_find_best_pos(stbrp_context *c, int width, int height) +{ + int best_waste = (1<<30), best_x, best_y = STBRP__HUGE_Y; + 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; + 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 (waste < best_waste) { + // can only use it if it first vertically + if (y + height <= c->height) { + 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->x <= c->width) { + int xpos = tail->x - width; + int y,waste; + assert(xpos >= 0); + // find the left position that matches this + while (node->next->x <= xpos) { + prev = &node; + node = node->next; + } + assert(node->next->x > xpos && node->x <= xpos); + y = stbrp__skyline_find_min_y(c, node, xpos, width, &waste); + if (waste <= best_waste && y + height < c->height) { + if (waste < best_waste || y < best_y || (y==best_y && xpos < best_x)) { + best_x = xpos; + best_y = y; + best_waste = waste; + best = prev; + } + } + tail = tail->next; + } + } + + fr.prev_link = prev; + 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 = res.x; + node->y = 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 nodes, until we get to one + // that shouldn't be freed + while (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->next; + cur = next; + } + + // stich the list back in + node->next = cur; + + if (cur->x < res.x + width) + cur->x = res.x+width; + +#ifdef _DEBUG + cur = context->active_head; + while (cur->x < context->width) { + assert(cur->x < cur->next->x); + cur = cur->next; + } + assert(cur->next == NULL); +#endif + + return res; +} + +static int rect_height_compare(const void *a, const void *b) +{ + stbrp_rect *p = (stbrp_rect *) a; + stbrp_rect *q = (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) +{ + stbrp_rect *p = (stbrp_rect *) a; + stbrp_rect *q = (stbrp_rect *) b; + return (p->was_packed < q->was_packed) ? -1 : (p->was_packed > q->was_packed); +} + +STBRP_DEF void stbrp_pack_rects(stbrp_context *context, stbrp_rect *rects, int num_rects) +{ + int i; + + // 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 + qsort(rects, num_rects, sizeof(rects[0]), rect_height_compare); + + for (i=0; i < num_rects; ++i) { + stbrp__findresult fr = stbrp__skyline_pack_rectangle(context, rects[i].w, rects[i].h); + if (fr.prev_link) { + rects[i].x = (unsigned short) fr.x; + rects[i].y = (unsigned short) fr.y; + } else { + rects[i].x = rects[i].y = 0xffff; + } + } + + // unsort + qsort(rects, num_rects, sizeof(rects[0]), rect_original_order); + + // set was_packed flags + for (i=0; i < num_rects; ++i) + rects[i].was_packed = !(rects[i].x == 0xffff && rects[i].y == 0xffff); +} +#endif From 0c10e7c40eab2af30b2b3964630a526e52cb2c4e Mon Sep 17 00:00:00 2001 From: Sean Barrett Date: Mon, 24 Nov 2014 17:47:06 -0800 Subject: [PATCH 2/5] tested & debugged on two cases (both heuristics); unknown if BF is *correct*. --- stb_rect_pack.h | 133 +++++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 102 insertions(+), 31 deletions(-) diff --git a/stb_rect_pack.h b/stb_rect_pack.h index 5800420..6f1065c 100644 --- a/stb_rect_pack.h +++ b/stb_rect_pack.h @@ -30,17 +30,26 @@ typedef struct stbrp_context stbrp_context; typedef struct stbrp_node stbrp_node; typedef struct stbrp_rect stbrp_rect; -enum -{ - STBRP_HEURISTIC_Skyline_default=0, - STBRP_HEURISTIC_Skyline_BL_sortHeight = STBRP_HEURISTIC_Skyline_default, - STBRP_HEURISTIC_Skyline_BF_sortHeight, -}; +#ifdef STBRP_LARGE_RECTS +typedef int stbrp_coord; +#else +typedef unsigned short stbrp_coord; +#endif -STBRP_DEF void stbrp_init_packer (stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes); -STBRP_DEF void stbrp_allow_oom (stbrp_context *context, int allow_out_of_mem); -STBRP_DEF void stbrp_set_heuristic(stbrp_context *context, int heuristic); -STBRP_DEF void stbrp_pack_rects (stbrp_context *context, stbrp_rect *rects, int num_rects); +STBRP_DEF void stbrp_pack_rects (stbrp_context *context, stbrp_rect *rects, int num_rects); +// Assign packing 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. struct stbrp_rect { @@ -48,19 +57,52 @@ struct stbrp_rect int id; // input: - unsigned short w, h; + stbrp_coord w, h; // output: - unsigned short x, y; + stbrp_coord x, y; int was_packed; // non-zero if valid packing + }; // 16 bytes, nominally + +STBRP_DEF void stbrp_init_packer (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 +// +// 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. + + +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. +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 manage the memory allocations for them +// be visible so you can handle the memory allocations for them struct stbrp_node { - unsigned short x,y; - stbrp_node *next; + stbrp_coord x,y; + stbrp_node *next; }; struct stbrp_context @@ -73,7 +115,7 @@ struct stbrp_context int num_nodes; stbrp_node *active_head; stbrp_node *free_head; - stbrp_node extra[2]; // we allocate two extra nodes so user only needs to create 'width' for correctness, not width+1 + stbrp_node extra[2]; // we allocate two extra nodes so optimal user-node-count is 'width' not 'width+2' }; #ifdef __cplusplus @@ -92,7 +134,7 @@ enum STBRP__INIT_skyline = 1, }; -STBRP_DEF void stbrp_set_heuristic(stbrp_context *context, int heuristic) +STBRP_DEF void stbrp_setup_heuristic(stbrp_context *context, int heuristic) { switch (context->init_mode) { case STBRP__INIT_skyline: @@ -103,7 +145,7 @@ STBRP_DEF void stbrp_set_heuristic(stbrp_context *context, int heuristic) } } -STBRP_DEF void stbrp_allow_oom(stbrp_context *context, int allow_out_of_mem) +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; @@ -126,6 +168,10 @@ STBRP_DEF void stbrp_allow_oom(stbrp_context *context, int allow_out_of_mem) STBRP_DEF void stbrp_init_packer(stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes) { int i; +#ifndef STBRP_LARGE_RECTS + assert(width <= 0xffff && height <= 0xffff); +#endif + for (i=0; i < num_nodes-1; ++i) nodes[i].next = &nodes[i+1]; nodes[i].next = NULL; @@ -134,16 +180,21 @@ STBRP_DEF void stbrp_init_packer(stbrp_context *context, int width, int height, context->free_head = &nodes[0]; context->active_head = &context->extra[0]; context->width = width; + context->height = height; context->num_nodes = num_nodes; - stbrp_allow_oom(context, 0); + 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 = width; +#ifdef STBRP_LARGE_RECTS + context->extra[1].y = (1<<30); +#else context->extra[1].y = 65535; - context->extra[2].next = NULL; +#endif + context->extra[1].next = NULL; } // find minimum y position if it starts at x1 @@ -171,7 +222,7 @@ static int stbrp__skyline_find_min_y(stbrp_context *c, stbrp_node *first, int x0 if (node->y > min_y) { // raise min_y higher. // we've accounted for all waste up to min_y, - // but we'll now ad more waste for everything we've visted + // but we'll now add more waste for everything we've visted waste_area += visited_width * (node->y - min_y); min_y = node->y; } else { @@ -195,11 +246,9 @@ typedef struct stbrp_node **prev_link; } stbrp__findresult; -#define STBRP__HUGE_Y (1<<30) - static stbrp__findresult stbrp__skyline_find_best_pos(stbrp_context *c, int width, int height) { - int best_waste = (1<<30), best_x, best_y = STBRP__HUGE_Y; + int best_waste = (1<<30), best_x, best_y = (1 << 30); stbrp__findresult fr; stbrp_node **prev, *node, *tail, **best = NULL; @@ -283,7 +332,7 @@ static stbrp__findresult stbrp__skyline_find_best_pos(stbrp_context *c, int widt } } - fr.prev_link = prev; + fr.prev_link = best; fr.x = best_x; fr.y = best_y; return fr; @@ -325,17 +374,17 @@ static stbrp__findresult stbrp__skyline_pack_rectangle(stbrp_context *context, i *res.prev_link = node; } - // from here, traverse cur and free nodes, until we get to one + // from here, traverse cur and free the nodes, until we get to one // that shouldn't be freed while (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->next; + context->free_head = cur; cur = next; } - // stich the list back in + // stitch the list back in node->next = cur; if (cur->x < res.x + width) @@ -348,6 +397,24 @@ static stbrp__findresult stbrp__skyline_pack_rectangle(stbrp_context *context, i cur = cur->next; } assert(cur->next == NULL); + + { + stbrp_node *L1 = NULL, *L2 = NULL; + int count=0; + cur = context->active_head; + while (cur) { + L1 = cur; + cur = cur->next; + ++count; + } + cur = context->free_head; + while (cur) { + L2 = cur; + cur = cur->next; + ++count; + } + assert(count == context->num_nodes+2); + } #endif return res; @@ -376,8 +443,12 @@ STBRP_DEF void stbrp_pack_rects(stbrp_context *context, stbrp_rect *rects, int n int i; // we use the 'was_packed' field internally to allow sorting/unsorting - for (i=0; i < num_rects; ++i) + for (i=0; i < num_rects; ++i) { rects[i].was_packed = i; + #ifndef STBRP_LARGE_RECTS + assert(rects[i].w <= 0xffff && rects[i].h <= 0xffff); + #endif + } // sort according to heuristic qsort(rects, num_rects, sizeof(rects[0]), rect_height_compare); @@ -385,8 +456,8 @@ STBRP_DEF void stbrp_pack_rects(stbrp_context *context, stbrp_rect *rects, int n for (i=0; i < num_rects; ++i) { stbrp__findresult fr = stbrp__skyline_pack_rectangle(context, rects[i].w, rects[i].h); if (fr.prev_link) { - rects[i].x = (unsigned short) fr.x; - rects[i].y = (unsigned short) fr.y; + rects[i].x = (stbrp_coord) fr.x; + rects[i].y = (stbrp_coord) fr.y; } else { rects[i].x = rects[i].y = 0xffff; } From 8d3ef72e3ce083ae7471e29115af9d41852f77c8 Mon Sep 17 00:00:00 2001 From: Sean Barrett Date: Mon, 24 Nov 2014 18:12:46 -0800 Subject: [PATCH 3/5] fixed bugs related to the best-fit heuristic --- stb_rect_pack.h | 37 +++++++++++++++++++++++++------------ 1 file changed, 25 insertions(+), 12 deletions(-) diff --git a/stb_rect_pack.h b/stb_rect_pack.h index 6f1065c..47a074d 100644 --- a/stb_rect_pack.h +++ b/stb_rect_pack.h @@ -1,17 +1,24 @@ // stb_rect_pack.h - v0.01 - public domain - rectangle packing +// Sean Barrett 2014 // // Useful for e.g. packing rectangular textures into an atlas. +// Does not do rotation. // -// By Sean Barrett and Ryan Gordon +// 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 stblib. // // 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. Contact me for details of how to set up the -// heuristic enums and suchlike (as the code currently isn't -// designed to do that correctly internally). -// +// function. #ifndef STB_INCLUDE_STB_RECT_PACK_H #define STB_INCLUDE_STB_RECT_PACK_H @@ -37,7 +44,7 @@ typedef unsigned short stbrp_coord; #endif STBRP_DEF void stbrp_pack_rects (stbrp_context *context, stbrp_rect *rects, int num_rects); -// Assign packing locations to rectangles. The rectangles are of type +// 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. // @@ -139,6 +146,7 @@ STBRP_DEF void stbrp_setup_heuristic(stbrp_context *context, int heuristic) switch (context->init_mode) { case STBRP__INIT_skyline: assert(heuristic == STBRP_HEURISTIC_Skyline_BL_sortHeight || heuristic == STBRP_HEURISTIC_Skyline_BF_sortHeight); + context->heuristic = heuristic; break; default: assert(0); @@ -218,21 +226,26 @@ static int stbrp__skyline_find_min_y(stbrp_context *c, stbrp_node *first, int x0 min_y = 0; waste_area = 0; visited_width = 0; - while (node->x <= x1) { + 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; } - visited_width += node->next->x - node->x; // adds too much the last time, but that's never used node = node->next; } @@ -259,7 +272,7 @@ static stbrp__findresult stbrp__skyline_find_best_pos(stbrp_context *c, int widt node = c->active_head; prev = &c->active_head; - while (node->x + width < c->width) { + 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 @@ -309,13 +322,13 @@ static stbrp__findresult stbrp__skyline_find_best_pos(stbrp_context *c, int widt // find first node that's admissible while (tail->x < width) tail = tail->next; - while (tail->x <= c->width) { + while (tail) { int xpos = tail->x - width; int y,waste; assert(xpos >= 0); // find the left position that matches this while (node->next->x <= xpos) { - prev = &node; + prev = &node->next; node = node->next; } assert(node->next->x > xpos && node->x <= xpos); @@ -376,7 +389,7 @@ static stbrp__findresult stbrp__skyline_pack_rectangle(stbrp_context *context, i // from here, traverse cur and free the nodes, until we get to one // that shouldn't be freed - while (cur->next->x <= res.x + width) { + 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; From a9e1f96765d6cd335af26c14b379470f6d23c0e5 Mon Sep 17 00:00:00 2001 From: Sean Barrett Date: Mon, 24 Nov 2014 18:20:13 -0800 Subject: [PATCH 4/5] rename 'stbrp_init_packer' to 'stbrp_init_target' since it must be called for every target; clean up docs --- stb_rect_pack.h | 34 +++++++++++++++++++++++++++++++--- 1 file changed, 31 insertions(+), 3 deletions(-) diff --git a/stb_rect_pack.h b/stb_rect_pack.h index 47a074d..62d9a4b 100644 --- a/stb_rect_pack.h +++ b/stb_rect_pack.h @@ -20,6 +20,12 @@ // implement them to the same API, but with a different init // function. + +////////////////////////////////////////////////////////////////////////////// +// +// INCLUDE SECTION +// + #ifndef STB_INCLUDE_STB_RECT_PACK_H #define STB_INCLUDE_STB_RECT_PACK_H @@ -57,6 +63,13 @@ STBRP_DEF void stbrp_pack_rects (stbrp_context *context, stbrp_rect *rects, int // 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. struct stbrp_rect { @@ -73,11 +86,17 @@ struct stbrp_rect }; // 16 bytes, nominally -STBRP_DEF void stbrp_init_packer (stbrp_context *context, int width, int height, stbrp_node *nodes, int num_nodes); +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' @@ -91,11 +110,14 @@ STBRP_DEF void stbrp_init_packer (stbrp_context *context, int width, int height, 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. 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. + enum { STBRP_HEURISTIC_Skyline_default=0, @@ -104,8 +126,11 @@ enum }; +////////////////////////////////////////////////////////////////////////////// +// // 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; @@ -131,7 +156,10 @@ struct stbrp_context #endif - +////////////////////////////////////////////////////////////////////////////// +// +// IMPLEMENTATION SECTION +// #ifdef STB_RECT_PACK_IMPLEMENTATION #include @@ -173,7 +201,7 @@ STBRP_DEF void stbrp_setup_allow_out_of_mem(stbrp_context *context, int allow_ou } } -STBRP_DEF void stbrp_init_packer(stbrp_context *context, int width, int height, stbrp_node *nodes, int 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 From 2c56e11c59c8373b81b0bb49562fe88cba088d4e Mon Sep 17 00:00:00 2001 From: Sean Barrett Date: Mon, 24 Nov 2014 18:21:36 -0800 Subject: [PATCH 5/5] doc tweaks --- stb_rect_pack.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/stb_rect_pack.h b/stb_rect_pack.h index 62d9a4b..38cd75a 100644 --- a/stb_rect_pack.h +++ b/stb_rect_pack.h @@ -110,13 +110,13 @@ STBRP_DEF void stbrp_init_target (stbrp_context *context, int width, int height, 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. +// 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. +// If you call init again, this will be reset to the default. enum {