compress fonts using zlib

- smaller
- better
- ugly big-endian workaround no longer necessary

src/gui/fontzlib.cpp

@@ -0,0 +1,125 @@
+/**
+ * Furnace Tracker - multi-system chiptune tracker
+ * Copyright (C) 2021-2024 tildearrow and contributors
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "gui.h"
+#include <zlib.h>
+
+#define FONT_READ_SIZE 262144
+
+struct InflateBlock {
+  unsigned char* buf;
+  size_t len;
+  size_t blockSize;
+  InflateBlock(size_t s) {
+    buf=new unsigned char[s];
+    len=s;
+    blockSize=0;
+  }
+  ~InflateBlock() {
+    delete[] buf;
+    len=0;
+  }
+};
+
+ImFont* FurnaceGUI::addFontZlib(const void* data, size_t len, float size_pixels, const ImFontConfig* font_cfg, const ImWchar* glyph_ranges) {
+  z_stream zl;
+  memset(&zl,0,sizeof(z_stream));
+  logV("addFontZlib...");
+
+  zl.avail_in=len;
+  zl.next_in=(Bytef*)data;
+  zl.zalloc=NULL;
+  zl.zfree=NULL;
+  zl.opaque=NULL;
+
+  int nextErr;
+  nextErr=inflateInit(&zl);
+  if (nextErr!=Z_OK) {
+    if (zl.msg==NULL) {
+      logD("zlib error: unknown! %d",nextErr);
+    } else {
+      logD("zlib error: %s",zl.msg);
+    }
+    inflateEnd(&zl);
+    return NULL;
+  }
+
+  std::vector<InflateBlock*> blocks;
+  while (true) {
+    InflateBlock* ib=new InflateBlock(FONT_READ_SIZE);
+    zl.next_out=ib->buf;
+    zl.avail_out=ib->len;
+
+    nextErr=inflate(&zl,Z_SYNC_FLUSH);
+    if (nextErr!=Z_OK && nextErr!=Z_STREAM_END) {
+      if (zl.msg==NULL) {
+        logD("zlib error: unknown error! %d",nextErr);
+      } else {
+        logD("zlib inflate: %s",zl.msg);
+      }
+      for (InflateBlock* i: blocks) delete i;
+      blocks.clear();
+      delete ib;
+      inflateEnd(&zl);
+      return NULL;
+    }
+    ib->blockSize=ib->len-zl.avail_out;
+    blocks.push_back(ib);
+    if (nextErr==Z_STREAM_END) {
+      break;
+    }
+  }
+  nextErr=inflateEnd(&zl);
+  if (nextErr!=Z_OK) {
+    if (zl.msg==NULL) {
+      logD("zlib end error: unknown error! %d",nextErr);
+    } else {
+      logD("zlib end: %s",zl.msg);
+    }
+    for (InflateBlock* i: blocks) delete i;
+    blocks.clear();
+    return NULL;
+  }
+
+  size_t finalSize=0;
+  size_t curSeek=0;
+  for (InflateBlock* i: blocks) {
+    finalSize+=i->blockSize;
+  }
+  if (finalSize<1) {
+    logD("compressed too small!");
+    lastError="file too small";
+    for (InflateBlock* i: blocks) delete i;
+    blocks.clear();
+    return NULL;
+  }
+  unsigned char* finalData=new unsigned char[finalSize];
+  for (InflateBlock* i: blocks) {
+    memcpy(&finalData[curSeek],i->buf,i->blockSize);
+    curSeek+=i->blockSize;
+    delete i;
+  }
+  blocks.clear();
+  len=finalSize;
+
+  ImFontConfig fontConfig=(font_cfg==NULL)?ImFontConfig():(*font_cfg);
+  fontConfig.FontDataOwnedByAtlas=true;
+
+  return ImGui::GetIO().Fonts->AddFontFromMemoryTTF(finalData,finalSize,size_pixels,&fontConfig,glyph_ranges);
+}