an initial draft of the new font rendering

3 files changed, 835 insertions, 160 deletions

diff --git a/lib/stb_rect_pack.h b/lib/stb_rect_pack.h
new file mode 100644
index 0000000..6a633ce
--- /dev/null
+++ b/lib/stb_rect_pack.h
@@ -0,0 +1,623 @@
+// 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.
+//
+// Before #including,
+//
+//    #define STB_RECT_PACK_IMPLEMENTATION
+//
+// 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
+//
+// 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;
+
+typedef int            stbrp_coord;
+
+#define STBRP__MAXVAL  0x7fffffff
+// Mostly for internal use, but this is the maximum supported coordinate value.
+
+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;
+
+   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;
+
+   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 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);
+}
+
+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/stb_truetype.c b/stb_truetype.c
index 2df7a90..07af6b9 100644
--- a/stb_truetype.c
+++ b/stb_truetype.c
@@ -1,4 +1,4 @@
-// used for debug build to speed things up
+// used to speed things up for debug build
 // just exports everything in stb_truetype.h
 
 
@@ -17,7 +17,14 @@
 #define no_warn_end
 #endif
 
+#if !DEBUG
+#define STBTT_STATIC
+#define STBRP_STATIC
+#endif
 #define STB_TRUETYPE_IMPLEMENTATION
+#define STB_RECT_PACK_IMPLEMENTATION
+
 no_warn_start
+#include "lib/stb_rect_pack.h"
 #include "lib/stb_truetype.h"
 no_warn_end
diff --git a/text.c b/text.c
index c869a5e..f2994aa 100644
--- a/text.c
+++ b/text.c
@@ -1,31 +1,18 @@
 #include "ted.h"
-
+ 
+no_warn_start
 #if DEBUG
-typedef struct
-{
-   unsigned short x0,y0,x1,y1; // coordinates of bbox in bitmap
-   float xoff,yoff,xadvance;
-} stbtt_bakedchar;
-typedef struct
-{
-   float x0,y0,s0,t0; // top-left
-   float x1,y1,s1,t1; // bottom-right
-} stbtt_aligned_quad;
-
-extern void stbtt_GetBakedQuad(const stbtt_bakedchar *chardata, int pw, int ph, int char_index, float *xpos, float *ypos, stbtt_aligned_quad *q, int opengl_fillrule); 
-extern int stbtt_BakeFontBitmap(const unsigned char *data, int offset, float pixel_height, unsigned char *pixels, int pw, int ph, int first_char, int num_chars, stbtt_bakedchar *chardata); 
+#include "lib/stb_rect_pack.h"
+#include "lib/stb_truetype.h"
 #else
-#define STBTT_STATIC
-no_warn_start
 #include "stb_truetype.c"
-no_warn_end
 #endif
+no_warn_end
 
-
-// We split up code points into a bunch of pages, so we don't have to load all of the font at
-// once into one texture.
-#define CHAR_PAGE_SIZE 2048
-#define CHAR_PAGE_COUNT UNICODE_CODE_POINTS / CHAR_PAGE_SIZE
+//no_warn_start
+//#define STB_IMAGE_WRITE_IMPLEMENTATION
+//#include "/~/apps/stb/stb_image_write.h"
+//no_warn_end
 
 typedef struct {
 	vec2 pos;
@@ -37,16 +24,37 @@ typedef struct {
 	TextVertex vert1, vert2, vert3;
 } TextTriangle;
 
+typedef struct {
+	char32_t c;
+	u32 texture;
+	stbtt_packedchar data;
+} CharInfo;
+
+// characters are split into this many "buckets" according to
+// their least significant bits. this is to create a Budget Hash Map™.
+// must be a power of 2.
+#define CHAR_BUCKET_COUNT (1 << 10)
+
+#define FONT_TEXTURE_WIDTH 512 // width of each texture
+#define FONT_TEXTURE_HEIGHT 512 // height of each texture
+
+typedef struct {
+	GLuint tex;
+	bool needs_update;
+	unsigned char *pixels;
+	TextTriangle *triangles;
+} FontTexture;
+
 struct Font {
 	bool force_monospace;
 	float space_width; // width of the character ' '. calculated when font is loaded.
 	float char_height;
-	GLuint textures[CHAR_PAGE_COUNT];
-	int tex_widths[CHAR_PAGE_COUNT], tex_heights[CHAR_PAGE_COUNT];
-	stbtt_bakedchar *char_pages[CHAR_PAGE_COUNT]; // character pages. NULL if the page hasn't been loaded yet.
+	stbtt_pack_context pack_context;
+	stbtt_fontinfo stb_info;
+	FontTexture *textures; // dynamic array of textures
+	CharInfo *char_info[CHAR_BUCKET_COUNT]; // each entry is a dynamic array of char info
 	// TTF data (i.e. the contents of the TTF file)
 	u8 *ttf_data;
-	TextTriangle *triangles[CHAR_PAGE_COUNT]; // triangles to render for each page
 };
 
 const TextRenderState text_render_state_default = {
@@ -122,14 +130,49 @@ void main() {\n\
 	return true;
 }
 
-static Status text_load_char_page(Font *font, int page) {
-	if (font->char_pages[page]) {
-		// already loaded
-		return true;
+static u32 char_bucket_index(char32_t c) {
+	return c & (CHAR_BUCKET_COUNT - 1);
+}
+
+// on success, *info is filled out
+static Status text_load_char(Font *font, char32_t c, CharInfo *info) {
+	u32 bucket = char_bucket_index(c);
+	arr_foreach_ptr(font->char_info[bucket], CharInfo, i) {
+		if (i->c == c) {
+			// already loaded
+			*info = *i;
+			return true;
+		}
 	}
 	
 	glGetError(); // clear error
 	
+	if (!font->textures) {
+		unsigned char *pixels = calloc(FONT_TEXTURE_WIDTH, FONT_TEXTURE_HEIGHT);
+		if (!pixels) {
+			text_set_err("Not enough memory for font bitmap.");
+			return false;
+		}
+		stbtt_PackBegin(&font->pack_context, pixels, FONT_TEXTURE_WIDTH, FONT_TEXTURE_HEIGHT,
+			FONT_TEXTURE_WIDTH, 1, NULL);
+		FontTexture *texture = arr_addp(font->textures);
+		glGenTextures(1, &texture->tex);
+		texture->pixels = pixels;
+	}
+	
+	FontTexture *texture = arr_lastp(font->textures);
+	{
+		info->c = c;
+		info->texture = arr_len(font->textures) - 1;
+		int success = stbtt_PackFontRange(&font->pack_context, font->ttf_data, 0, font->char_height,
+			(int)c, 1, &info->data);
+		printf("%lc %d\n",c,success);
+	}
+	texture->needs_update = true;
+	
+	arr_add(font->char_info[bucket], *info);
+	return true;
+#if 0
 	font->char_pages[page] = calloc(CHAR_PAGE_SIZE, sizeof *font->char_pages[page]);
 	for (int bitmap_width = 128, bitmap_height = 128; bitmap_width <= 4096; bitmap_width *= 2, bitmap_height *= 2) {
 		u8 *bitmap = calloc((size_t)bitmap_width, (size_t)bitmap_height);
@@ -174,6 +217,8 @@ static Status text_load_char_page(Font *font, int page) {
 		return false;
 	}
 	return true;
+#endif
+
 }
 
 Font *text_font_load(const char *ttf_filename, float font_size) {
@@ -182,40 +227,43 @@ Font *text_font_load(const char *ttf_filename, float font_size) {
 	
 	text_clear_err();
 
-	if (ttf_file) {
-		fseek(ttf_file, 0, SEEK_END);
-		u32 file_size = (u32)ftell(ttf_file);
-		fseek(ttf_file, 0, SEEK_SET);
-		if (file_size < (50UL<<20)) { // fonts aren't usually bigger than 50 MB
-			u8 *file_data = calloc(1, file_size);
-			font = calloc(1, sizeof *font);
-			if (file_data && font) {
-				size_t bytes_read = fread(file_data, 1, file_size, ttf_file);
-				if (bytes_read == file_size) {
-					font->char_height = font_size;
-					font->ttf_data = file_data;
-					if (text_load_char_page(font, 0)) { // load page with Latin text, etc.
-						// calculate width of the character ' '
-						font->space_width = font->char_pages[0][' '].xadvance;
-					}
-				} else {
-					text_set_err("Couldn't read font file.");
-				}
-			} else {
-				text_set_err("Not enough memory for font.");
-			}
-			if (text_has_err()) {
-				free(file_data);
-				free(font);
-				font = NULL;
+	if (!ttf_file) {
+		text_set_err("Couldn't open font file.", ttf_filename);
+		return NULL;
+	}
+	
+	fseek(ttf_file, 0, SEEK_END);
+	u32 file_size = (u32)ftell(ttf_file);
+	fseek(ttf_file, 0, SEEK_SET);
+	if (file_size >= (50UL<<20)) { // fonts aren't usually bigger than 50 MB
+		text_set_err("Font file too big (%u megabytes).", (uint)(file_size >> 20));
+		fclose(ttf_file);
+		return NULL;
+	}
+	u8 *file_data = calloc(1, file_size);
+	font = calloc(1, sizeof *font);
+	if (file_data && font) {
+		size_t bytes_read = fread(file_data, 1, file_size, ttf_file);
+		if (bytes_read == file_size) {
+			font->char_height = font_size;
+			font->ttf_data = file_data;
+			CharInfo space = {0};
+			if (text_load_char(font, ' ', &space)) {
+				// calculate width of the character ' '
+				font->space_width = space.data.xadvance;
 			}
-			fclose(ttf_file);
 		} else {
-			text_set_err("Font file too big (%u megabytes).", (uint)(file_size >> 20));
+			text_set_err("Couldn't read font file.");
 		}
 	} else {
-		text_set_err("Couldn't open font file.", ttf_filename);
+		text_set_err("Not enough memory for font.");
 	}
+	if (text_has_err()) {
+		free(file_data);
+		free(font);
+		font = NULL;
+	}
+	fclose(ttf_file);
 	return font;
 }
 
@@ -229,24 +277,31 @@ float text_font_char_height(Font *font) {
 
 float text_font_char_width(Font *font, char32_t c) {
 	if (c == ' ') return font->space_width;
-	uint page = c / CHAR_PAGE_SIZE;
-	uint index = c % CHAR_PAGE_SIZE;
-	if (!font->char_pages[page])
-		if (!text_load_char_page(font, (int)page))
-			return font->space_width;
-	return font->char_pages[page][index].xadvance;
+	CharInfo info = {0};
+	if (text_load_char(font, c, &info))
+		return info.data.xadvance;
+	else
+		return 0;
 }
 
 void text_render(Font *font) {
-	for (uint i = 0; i < CHAR_PAGE_COUNT; ++i) {
-		if (font->triangles[i]) {
+	arr_foreach_ptr(font->textures, FontTexture, texture) {
+		size_t ntriangles = arr_len(texture->triangles);
+		if (ntriangles) {
+			if (texture->needs_update) {
+				glBindTexture(GL_TEXTURE_2D, texture->tex);
+				glTexImage2D(GL_TEXTURE_2D, 0, GL_RED, FONT_TEXTURE_WIDTH, FONT_TEXTURE_HEIGHT, 0, GL_RED, GL_UNSIGNED_BYTE, texture->pixels);
+				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+				glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+				
+				//stbi_write_png("out.png", FONT_TEXTURE_WIDTH, FONT_TEXTURE_HEIGHT, 1, texture->pixels, FONT_TEXTURE_WIDTH);
+     				texture->needs_update = false;
+			}
 			// render these triangles
-			size_t ntriangles = arr_len(font->triangles[i]);
-		
 			if (gl_version_major >= 3)
 				glBindVertexArray(text_vao);
 			glBindBuffer(GL_ARRAY_BUFFER, text_vbo);
-			glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)(ntriangles * sizeof(TextTriangle)), font->triangles[i], GL_STREAM_DRAW);
+			glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)(ntriangles * sizeof(TextTriangle)), texture->triangles, GL_STREAM_DRAW);
 			glVertexAttribPointer(text_v_pos, 2, GL_FLOAT, 0, sizeof(TextVertex), (void *)offsetof(TextVertex, pos));
 			glEnableVertexAttribArray(text_v_pos);
 			glVertexAttribPointer(text_v_tex_coord, 2, GL_FLOAT, 0, sizeof(TextVertex), (void *)offsetof(TextVertex, tex_coord));
@@ -255,11 +310,11 @@ void text_render(Font *font) {
 			glEnableVertexAttribArray(text_v_color);
 			glUseProgram(text_program);
 			glActiveTexture(GL_TEXTURE0);
-			glBindTexture(GL_TEXTURE_2D, font->textures[i]);
+			glBindTexture(GL_TEXTURE_2D, texture->tex);
 			glUniform1i(text_u_sampler, 0);
 			glUniform2f(text_u_window_size, gl_window_width, gl_window_height);
 			glDrawArrays(GL_TRIANGLES, 0, (GLsizei)(3 * ntriangles));
-			arr_clear(font->triangles[i]);
+			arr_clear(texture->triangles);
 		}
 	}
 }
@@ -274,94 +329,86 @@ top:
 	}
 	if (c >= UNICODE_CODE_POINTS) c = UNICODE_BOX_CHARACTER; // code points this big should never appear in valid Unicode
 	
+	CharInfo info = {0};
+
+	if (!text_load_char(font, c, &info))
+		return;
+	const float char_height = font->char_height;
 	
-	uint page = c / CHAR_PAGE_SIZE;
-	uint index = c % CHAR_PAGE_SIZE;
-	if (state->render) {
-		if (!font->char_pages[page])
-			if (!text_load_char_page(font, (int)page))
-				return;
+	stbtt_aligned_quad q = {0};
+	
+	if (state->wrap && c == '\n') {
+		state->x = state->min_x;
+		state->y += char_height;
+		goto ret;
 	}
-	stbtt_bakedchar *char_data = font->char_pages[page];
-	const float char_height = font->char_height;
 	
-	if (char_data) { // if page was successfully loaded
-		stbtt_aligned_quad q = {0};
-		
-		if (state->wrap && c == '\n') {
-			state->x = state->min_x;
-			state->y += char_height;
-			goto ret;
-		}
+	{
+		float x, y;
+		x = (float)(state->x - floor(state->x));
+		y = (float)(state->y - floor(state->y));
+		y += char_height * 0.75f;
+		stbtt_GetPackedQuad(&info.data, FONT_TEXTURE_WIDTH, FONT_TEXTURE_HEIGHT, 0, &x, &y, &q, 1);
+		y -= char_height * 0.75f;
 		
-		{
-			float x, y;
-			x = (float)(state->x - floor(state->x));
-			y = (float)(state->y - floor(state->y));
-			y += char_height * 0.75f;
-			stbtt_GetBakedQuad(char_data, font->tex_widths[page], font->tex_heights[page],
-				(int)index, &x, &y, &q, 1);
-			y -= char_height * 0.75f;
-			
-			q.x0 += (float)floor(state->x);
-			q.y0 += (float)floor(state->y);
-			q.x1 += (float)floor(state->x);
-			q.y1 += (float)floor(state->y);
-			
-			if (font->force_monospace) {
-				state->x += font->space_width; // ignore actual character width
-			} else {
-				state->x = x + floor(state->x);
-				state->y = y + floor(state->y);
-			}
-		}
+		q.x0 += (float)floor(state->x);
+		q.y0 += (float)floor(state->y);
+		q.x1 += (float)floor(state->x);
+		q.y1 += (float)floor(state->y);
 		
-		float s0 = q.s0, t0 = q.t0;
-		float s1 = q.s1, t1 = q.t1;
-		float x0 = q.x0, y0 = q.y0;
-		float x1 = q.x1, y1 = q.y1;
-		const float min_x = state->min_x, max_x = state->max_x;
-		const float min_y = state->min_y, max_y = state->max_y;
-		
-		if (state->wrap && x1 >= max_x) {
-			state->x = min_x;
-			state->y += char_height;
-			goto top;
+		if (font->force_monospace) {
+			state->x += font->space_width; // ignore actual character width
+		} else {
+			state->x = x + floor(state->x);
+			state->y = y + floor(state->y);
 		}
+	}
+	
+	float s0 = q.s0, t0 = q.t0;
+	float s1 = q.s1, t1 = q.t1;
+	float x0 = q.x0, y0 = q.y0;
+	float x1 = q.x1, y1 = q.y1;
+	const float min_x = state->min_x, max_x = state->max_x;
+	const float min_y = state->min_y, max_y = state->max_y;
+	
+	if (state->wrap && x1 >= max_x) {
+		state->x = min_x;
+		state->y += char_height;
+		goto top;
+	}
 
-		if (x0 > max_x || y0 > max_y || x1 < min_x || y1 < min_y)
-			goto ret;
-		if (x0 < min_x) {
-			// left side of character is clipped
-			s0 = (min_x-x0) / (x1-x0) * (s1-s0) + s0;
-			x0 = min_x;
-		}
-		if (x1 >= max_x) {
-			// right side of character is clipped
-			s1 = (max_x-1-x0) / (x1-x0) * (s1-s0) + s0;
-			x1 = max_x-1;
-		}
-		if (y0 < min_y) {
-			// top side of character is clipped
-			t0 = (min_y-y0) / (y1-y0) * (t1-t0) + t0;
-			y0 = min_y;
-		}
-		if (y1 >= max_y) {
-			// bottom side of character is clipped
-			t1 = (max_y-1-y0) / (y1-y0) * (t1-t0) + t0;
-			y1 = max_y-1;
-		}
-		if (state->render) {
-			float r = state->color[0], g = state->color[1], b = state->color[2], a = state->color[3];
-			TextVertex v_1 = {{x0, y0}, {s0, t0}, {r, g, b, a}};
-			TextVertex v_2 = {{x0, y1}, {s0, t1}, {r, g, b, a}};
-			TextVertex v_3 = {{x1, y1}, {s1, t1}, {r, g, b, a}};
-			TextVertex v_4 = {{x1, y0}, {s1, t0}, {r, g, b, a}};
-			TextTriangle triangle1 = {v_1, v_2, v_3};
-			TextTriangle triangle2 = {v_3, v_4, v_1};
-			arr_add(font->triangles[page], triangle1);
-			arr_add(font->triangles[page], triangle2);
-		}
+	if (x0 > max_x || y0 > max_y || x1 < min_x || y1 < min_y)
+		goto ret;
+	if (x0 < min_x) {
+		// left side of character is clipped
+		s0 = (min_x-x0) / (x1-x0) * (s1-s0) + s0;
+		x0 = min_x;
+	}
+	if (x1 >= max_x) {
+		// right side of character is clipped
+		s1 = (max_x-1-x0) / (x1-x0) * (s1-s0) + s0;
+		x1 = max_x-1;
+	}
+	if (y0 < min_y) {
+		// top side of character is clipped
+		t0 = (min_y-y0) / (y1-y0) * (t1-t0) + t0;
+		y0 = min_y;
+	}
+	if (y1 >= max_y) {
+		// bottom side of character is clipped
+		t1 = (max_y-1-y0) / (y1-y0) * (t1-t0) + t0;
+		y1 = max_y-1;
+	}
+	if (state->render) {
+		float r = state->color[0], g = state->color[1], b = state->color[2], a = state->color[3];
+		TextVertex v_1 = {{x0, y0}, {s0, t0}, {r, g, b, a}};
+		TextVertex v_2 = {{x0, y1}, {s0, t1}, {r, g, b, a}};
+		TextVertex v_3 = {{x1, y1}, {s1, t1}, {r, g, b, a}};
+		TextVertex v_4 = {{x1, y0}, {s1, t0}, {r, g, b, a}};
+		TextTriangle triangle1 = {v_1, v_2, v_3};
+		TextTriangle triangle2 = {v_3, v_4, v_1};
+		arr_add(font->textures[info.texture].triangles, triangle1);
+		arr_add(font->textures[info.texture].triangles, triangle2);
 	}
 	ret:
 	if (state->x > state->x_largest)
@@ -449,12 +496,10 @@ void text_get_size32(Font *font, const char32_t *text, u64 len, float *width, fl
 
 void text_font_free(Font *font) {
 	free(font->ttf_data);
-	stbtt_bakedchar **char_pages = font->char_pages;
-	for (int i = 0; i < CHAR_PAGE_COUNT; ++i) {
-		if (char_pages[i]) {
-			free(char_pages[i]);
-		}
-		arr_clear(font->triangles[i]);
+	arr_foreach_ptr(font->textures, FontTexture, texture) {
+		glDeleteTextures(1, &texture->tex);
+		arr_free(texture->triangles);
 	}
+	arr_free(font->textures);
 	free(font);
 }