cosmopolitan/third_party/stb/stb_rect_pack.c
Justine Tunney 23e235b7a5
Fix bugs in cosmocc toolchain
This change integrates e58abc1110b335a3341e8ad5821ad8e3880d9bb2 from
https://github.com/ahgamut/musl-cross-make/ which fixes the issues we
were having with our C language extension for symbolic constants. This
change also performs some code cleanup and bug fixes to getaddrinfo().
It's now possible to compile projects like ncurses, readline and python
without needing to patch anything upstream, except maybe a line or two.
Pretty soon it should be possible to build a Linux distro on Cosmo.
2023-06-08 23:44:03 -07:00

460 lines
17 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:3;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=3 sts=3 sw=3 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ │
│ stb_truetype │
│ Copyright 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. │
│ │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "third_party/stb/stb_rect_pack.h"
#include "libc/assert.h"
#include "libc/dce.h"
#include "libc/mem/alg.h"
asm(".ident\t\"\\n\\n\
stb_rect_pack (MIT License)\\n\
Copyright 2017 Sean Barrett\"");
asm(".include \"libc/disclaimer.inc\"");
/* clang-format off */
// stb_rect_pack.h - v1.01 - public domain - rectangle packing
// Sean Barrett 2014
//
// Useful for e.g. packing rectangular textures into an atlas.
// Does not do rotation.
//
// in the file that you want to have the implementation.
//
// 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:
//
// 1.01 (2021-07-11) always use large rect mode, expose STBRP__MAXVAL in public section
// 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
#define STBRP__INIT_skyline 1
typedef struct
{
int x,y;
stbrp_node **prev_link;
} stbrp__findresult;
// 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.
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:
__builtin_unreachable();
}
}
// 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).
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;
}
}
// 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.
void stbrp_init_target(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->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;
context->extra[1].y = (1<<30);
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;
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 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;
}
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;
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;
assert(xpos >= 0);
// find the left position that matches this
while (node->next->x <= xpos) {
prev = &node->next;
node = node->next;
}
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;
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);
#ifndef NDEBUG
cur = context->active_head;
while (cur->x < context->width) {
assert(cur->x < cur->next->x);
cur = cur->next;
}
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;
}
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);
}
// 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.
int stbrp_pack_rects(stbrp_context *context, stbrp_rect *rects, int num_rects)
{
stbrp__findresult fr;
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
qsort(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 {
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
qsort(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;
}