add font loading and rendering to daguerre

applications/init/source/main.cpp

@@ -1,9 +1,9 @@
 #include <daguerre.hpp>
 
-void overlay_encode(
+void alpha_overlay(
   daguerre::hilbert_color &dest, const daguerre::rgb24 &src) {
   if (src.r != 0xff || src.g != 0x00 || src.b != 0xff)
-    daguerre::encode(dest, src);
+    daguerre::default_overlay(dest, src);
 }
 
 void invert(daguerre::rgb24 &dest, const daguerre::rgb24 &src) {
@@ -17,14 +17,15 @@ int main(int, char **) {
   auto framebuffer = daguerre::get_hilbert_framebuffer();
 
   daguerre::image<daguerre::rgb24> burden;
-  std::FILE *burden_file = std::fopen("/assets/burden.ppm", "r");
-  daguerre::try_load_ppm(burden_file, burden);
-  std::fclose(burden_file);
+  daguerre::try_load_ppm("/assets/burden.ppm", burden);
 
   daguerre::image<daguerre::rgb24> pointer;
-  std::FILE *pointer_file = std::fopen("/assets/pointer.ppm", "r");
-  daguerre::try_load_ppm(pointer_file, pointer);
-  std::fclose(pointer_file);
+  daguerre::try_load_ppm("/assets/pointer.ppm", pointer);
+
+  daguerre::fixed_bitmap_font<bool> terminus;
+  daguerre::try_load_psf("/assets/terminus-bold-18x10.psf", terminus);
+
+  terminus.overlay_text<>(burden, 0, 0, "this is a test");
 
   int32_t width = burden.width < framebuffer.width
                 ? burden.width : framebuffer.width;
@@ -39,9 +40,7 @@ int main(int, char **) {
   int32_t old_mouse_y = new_mouse_y;
   bool was_left_mouse_down = false;
 
-  daguerre::overlay_region<
-    daguerre::hilbert_color, daguerre::rgb24, daguerre::encode>(
-    framebuffer, x, y, burden, 0, 0, width, height);
+  daguerre::overlay_region<>(framebuffer, x, y, burden, 0, 0, width, height);
 
   while (1) {
 
@@ -96,8 +95,7 @@ int main(int, char **) {
       daguerre::overlay_region<daguerre::rgb24, daguerre::rgb24, invert>(
         burden, 0, 0, burden, 0, 0, width, height);
 
-      daguerre::overlay_region<
-        daguerre::hilbert_color, daguerre::rgb24, daguerre::encode>(
+      daguerre::overlay_region<>(
         framebuffer, x, y, burden, 0, 0, width, height);
 
       anything_changed = true;
@@ -105,12 +103,11 @@ int main(int, char **) {
     }
 
     if (anything_changed) {
-      daguerre::overlay_region<
-        daguerre::hilbert_color, daguerre::rgb24, daguerre::encode>(
+      daguerre::overlay_region<>(
         framebuffer, old_mouse_x + x, old_mouse_y + y, burden,
         old_mouse_x, old_mouse_y, pointer.width, pointer.height);
       daguerre::overlay_region<
-        daguerre::hilbert_color, daguerre::rgb24, overlay_encode>(
+        daguerre::hilbert_color, daguerre::rgb24, alpha_overlay>(
         framebuffer, new_mouse_x + x, new_mouse_y + y,
         pointer, 0, 0, pointer.width, pointer.height);
     }

euler/include/cstdio

@@ -10,6 +10,11 @@ namespace std {
   FILE *fopen(const char *filename, const char *mode);
   int fclose(FILE *stream);
 
+  int fseek(FILE *stream, long offset, int origin);
+  #define SEEK_SET 0
+  #define SEEK_CUR 2
+  #define SEEK_END 1
+
   size_t fread(void *buffer, size_t size, size_t count, FILE *stream);
 
 }

euler/makefile

@@ -1,6 +1,6 @@
 LIBSTDCPP_SOURCES = euler/stream.cpp strings/strlen.cpp euler/syscall.asm \
   euler/entry.cpp io/fopen.cpp euler/gcc.asm memory/delete.cpp euler/heap.cpp \
-  memory/new.cpp io/fclose.cpp io/fread.cpp strings/memcpy.cpp
+  memory/new.cpp io/fclose.cpp io/fread.cpp strings/memcpy.cpp io/fseek.cpp
 
 clean:
 	rm -rf build

euler/source/io/fseek.cpp

@@ -0,0 +1,11 @@
+#include <cstdio>
+
+namespace std {
+
+  int fseek(FILE *stream, long offset, int origin) {
+    if (origin < 0 || origin > 2)
+      return 1;
+    return stream->try_seek((__euler_seek_from)origin, offset) ? 0 : 2;
+  }
+
+}

libraries/daguerre/include/daguerre.hpp

@@ -14,6 +14,16 @@ namespace daguerre {
     uint8_t b;
   };
 
+  static inline void default_overlay(hilbert_color &dest, const rgb24 &src) {
+    dest = __euler_encode_color(src.r, src.g, src.b);
+  }
+
+  static inline void default_overlay(rgb24 &dest, const bool &src) {
+    dest.r = src ? 255 : 0;
+    dest.g = src ? 255 : 0;
+    dest.b = src ? 255 : 0;
+  }
+
   template <class color_t>
   class image {
 
@@ -100,7 +110,7 @@ namespace daguerre {
   //from [from_x, from_x + width) x [from_y, from_y + height).
   template <
     class to_color_t, class from_color_t,
-    void overlay(to_color_t &dest, const from_color_t &src)>
+    void overlay(to_color_t &dest, const from_color_t &src) = default_overlay>
   void overlay_region(
     image<to_color_t> &to, unsigned to_x, unsigned to_y,
     const image<from_color_t> &from, unsigned from_x, unsigned from_y,
@@ -116,12 +126,60 @@ namespace daguerre {
 
   }
 
-  static inline void encode(hilbert_color &dest, const rgb24 &src) {
-    dest = __euler_encode_color(src.r, src.g, src.b);
-  }
-
   image<hilbert_color> get_hilbert_framebuffer();
 
   bool try_load_ppm(std::FILE *input, image<rgb24> &into);
 
+  static inline bool try_load_ppm(const char *path, image<rgb24> &into) {
+    std::FILE *f = std::fopen(path, "r");
+    if (!f)
+      return false;
+    bool success = try_load_ppm(f, into);
+    std::fclose(f);
+    return success;
+  }
+
+  //TODO: unicode
+  template <class color_t>
+  class fixed_bitmap_font {
+
+  public:
+    unsigned width;
+    unsigned height;
+    image<color_t> glyphs[128];
+
+    template <class target_color_t,
+      void overlay(target_color_t &dest, const color_t &src) = default_overlay>
+    void overlay_text(
+      image<target_color_t> &target, unsigned x,
+      unsigned y, const char *text) const {
+
+      while (1) {
+        uint8_t ch = (uint8_t)*text;
+        if (ch == 0)
+          return;
+        if (ch < 128) {
+          overlay_region<target_color_t, color_t, overlay>(
+            target, x, y, glyphs[ch], 0, 0, width, height);
+          x += width;
+        }
+        ++text;
+      }
+
+    }
+
+  };
+
+  bool try_load_psf(std::FILE *input, fixed_bitmap_font<bool> &into);
+
+  static inline bool try_load_psf(
+    const char *path, fixed_bitmap_font<bool> &into) {
+    std::FILE *f = std::fopen(path, "r");
+    if (!f)
+      return false;
+    bool success = try_load_psf(f, into);
+    std::fclose(f);
+    return success;
+  }
+
 }

libraries/daguerre/source/daguerre.cpp

@@ -26,6 +26,7 @@ namespace daguerre {
     return n;
   }
 
+  //only supports p6 format
   bool try_load_ppm(std::FILE *input, image<rgb24> &into) {
 
     char header[3];
@@ -62,4 +63,48 @@ namespace daguerre {
 
   }
 
+  //assumes the font is in psf2 format, and has a unicode table
+  bool try_load_psf(std::FILE *input, fixed_bitmap_font<bool> &into) {
+
+    uint32_t header[8];
+    if (std::fread(header, 4, 8, input) != 8)
+      return false;
+
+    const uint32_t glyphs_start = header[2];
+    const uint32_t glyph_count = header[4];
+    const uint32_t glyph_length = header[5];
+    into.height = header[6];
+    into.width = header[7];
+
+    const uint32_t unicode_start = glyphs_start + glyph_count * glyph_length;
+    std::fseek(input, unicode_start, SEEK_SET);
+
+    uint32_t indices[128];
+
+    for (uint32_t index = 0; index < glyph_count; ++index) {
+      uint8_t ch;
+      std::fread(&ch, 1, 1, input);
+      if (ch < 128)
+        indices[ch] = index;
+      do
+        std::fread(&ch, 1, 1, input);
+      while (ch != 0xff);
+    }
+
+    for (uint8_t ch = 0; ch < 128; ++ch) {
+      std::fseek(input, glyphs_start + glyph_length * indices[ch], SEEK_SET);
+      into.glyphs[ch] = image<bool>(into.width, into.height);
+      for (unsigned h = 0; h < into.height; ++h)
+        for (unsigned wb = 0; wb < into.width; wb += 8) {
+          uint8_t byte;
+          std::fread(&byte, 1, 1, input);
+          for (unsigned x = 0; x < 8 && wb + x < into.width; ++x)
+            into.glyphs[ch].set(wb + x, h, (byte >> (7 - x)) & 1);
+        }
+    }
+
+    return true;
+
+  }
+
 }

readme.txt

@@ -39,6 +39,11 @@ acknowledgements (any under "dependencies" are downloaded during build):
       license: https://unsplash.com/license
       source: https://unsplash.com/photos/selective-focus-photography-snowflakes-9yhy1FXlKwI
 
+  - skeleton/assets/terminus-bold-18x10.psf (terminus font, bold, 18x10)
+      copyright 2020 dimitar toshkov zhekov
+      license: skeleton/assets/terminus-ofl.txt (sil open font license v1.1)
+      homepage: https://terminus-font.sourceforge.net/
+
 everything in the following directories is copyright 2024 benji dial, under the
 license in license.txt (the isc license):
 

skeleton/assets/readme.txt

@@ -4,3 +4,7 @@ https://unsplash.com/photos/selective-focus-photography-snowflakes-9yhy1FXlKwI.
 its license can be found online at https://unsplash.com/license.
 
 the icon in pointer.ppm is by me :)
+
+the font in terminus-bold-18x10.psf is the "terminus" font, in bold weight, at
+18x10. it can be found only at https://terminus-font.sourceforge.net/ and is
+under the license in terminus-ofl.txt (the sil open font license v1.1).

skeleton/assets/terminus-ofl.txt

@@ -0,0 +1,94 @@
+Copyright (C) 2020 Dimitar Toshkov Zhekov,
+with Reserved Font Name "Terminus Font".
+
+This Font Software is licensed under the SIL Open Font License, Version 1.1.
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
+
+
+-----------------------------------------------------------
+SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+-----------------------------------------------------------
+
+PREAMBLE
+The goals of the Open Font License (OFL) are to stimulate worldwide
+development of collaborative font projects, to support the font creation
+efforts of academic and linguistic communities, and to provide a free and
+open framework in which fonts may be shared and improved in partnership
+with others.
+
+The OFL allows the licensed fonts to be used, studied, modified and
+redistributed freely as long as they are not sold by themselves. The
+fonts, including any derivative works, can be bundled, embedded,
+redistributed and/or sold with any software provided that any reserved
+names are not used by derivative works. The fonts and derivatives,
+however, cannot be released under any other type of license. The
+requirement for fonts to remain under this license does not apply
+to any document created using the fonts or their derivatives.
+
+DEFINITIONS
+"Font Software" refers to the set of files released by the Copyright
+Holder(s) under this license and clearly marked as such. This may
+include source files, build scripts and documentation.
+
+"Reserved Font Name" refers to any names specified as such after the
+copyright statement(s).
+
+"Original Version" refers to the collection of Font Software components as
+distributed by the Copyright Holder(s).
+
+"Modified Version" refers to any derivative made by adding to, deleting,
+or substituting -- in part or in whole -- any of the components of the
+Original Version, by changing formats or by porting the Font Software to a
+new environment.
+
+"Author" refers to any designer, engineer, programmer, technical
+writer or other person who contributed to the Font Software.
+
+PERMISSION & CONDITIONS
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of the Font Software, to use, study, copy, merge, embed, modify,
+redistribute, and sell modified and unmodified copies of the Font
+Software, subject to the following conditions:
+
+1) Neither the Font Software nor any of its individual components,
+in Original or Modified Versions, may be sold by itself.
+
+2) Original or Modified Versions of the Font Software may be bundled,
+redistributed and/or sold with any software, provided that each copy
+contains the above copyright notice and this license. These can be
+included either as stand-alone text files, human-readable headers or
+in the appropriate machine-readable metadata fields within text or
+binary files as long as those fields can be easily viewed by the user.
+
+3) No Modified Version of the Font Software may use the Reserved Font
+Name(s) unless explicit written permission is granted by the corresponding
+Copyright Holder. This restriction only applies to the primary font name as
+presented to the users.
+
+4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+Software shall not be used to promote, endorse or advertise any
+Modified Version, except to acknowledge the contribution(s) of the
+Copyright Holder(s) and the Author(s) or with their explicit written
+permission.
+
+5) The Font Software, modified or unmodified, in part or in whole,
+must be distributed entirely under this license, and must not be
+distributed under any other license. The requirement for fonts to
+remain under this license does not apply to any document created
+using the Font Software.
+
+TERMINATION
+This license becomes null and void if any of the above conditions are
+not met.
+
+DISCLAIMER
+THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
+COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
+OTHER DEALINGS IN THE FONT SOFTWARE.