5 files changed, 214 insertions, 0 deletions
diff --git a/src/user/libfont/bdf.c b/src/user/libfont/bdf.c
new file mode 100644
index 0000000..2c19a15
--- /dev/null
+++ b/src/user/libfont/bdf.c
@@ -0,0 +1,99 @@
+#include <libfont/fonts.h>
+
+#include <knob/format.h>
+#include <knob/panic.h>
+#include <knob/block.h>
+#include <knob/heap.h>
+#include <knob/file.h>
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#define LINE_BUF_SIZE 1000
+char line_buf[LINE_BUF_SIZE];
+
+static inline uint8_t hex_to_n(char ch) {
+  return ch - (ch >= 'A' ? 'A' - 10 : '0');
+}
+
+//very minimal implementation
+bool try_load_bdf(const char *path, struct font_info *into) {
+  struct file *f = open_file(path);
+  if (!f)
+    PANIC("Can't open font file sent by get_font.");
+
+  read_line_from_file(f, line_buf, LINE_BUF_SIZE - 1);
+  if (!strequ(line_buf, "STARTFONT 2.1")) {
+    close_file(f);
+    return false;
+  }
+
+  for (uint16_t i = 0; i < 256; ++i)
+    into->bitmaps[i] = 0;
+  into->space_height = -1;
+  into->space_width = -1;
+  into->char_height = -1;
+  into->char_width = -1;
+
+  uint32_t current = 0;
+
+  while (read_line_from_file(f, line_buf, LINE_BUF_SIZE - 1)) {
+    if (blockequ(line_buf, "FONTBOUNDINGBOX ", 16)) {
+      uint32_t n;
+      uint32_t l = try_swtou(line_buf + 16, &n);
+      if (!l)
+        goto bad_format;
+      into->space_width = n;
+      into->char_width = n;
+      l = try_swtou(line_buf + 16 + l, &n);
+      if (!l)
+        goto bad_format;
+      into->space_height = n;
+      into->char_height = n;
+    }
+    else if (blockequ(line_buf, "ENCODING ", 9)) {
+      if (!try_swtou(line_buf + 9, &current))
+        goto bad_format;
+    }
+    else if (strequ(line_buf, "BITMAP")) {
+      if (current >= 256)
+        continue;
+      bool *bm = get_block(into->char_height * into->char_width);
+      if (!bm)
+        PANIC("could not allocate memory for font character bitmap");
+      into->bitmaps[current] = bm;
+
+      for (uint32_t y = 0; y < into->char_height; ++y) {
+        read_line_from_file(f, line_buf, LINE_BUF_SIZE - 1);
+        for (uint32_t x = 0; x < into->char_width; ++x)
+          bm[y * into->char_width + x] = (hex_to_n(line_buf[x / 4]) >> (3 - x % 4)) & 1;
+      }
+    }
+  }
+
+  close_file(f);
+  f = 0;
+
+  if ((into->char_height  == -1) ||
+      (into->char_width   == -1) ||
+      (into->space_height == -1) ||
+      (into->space_width  == -1))
+    goto bad_format;
+
+  if (!into->bitmaps[0]) {
+    const uint32_t bytes = (into->char_height * into->char_width - 1) / 8 + 1;
+    into->bitmaps[0] = get_block(bytes);
+    for (uint32_t i = 0; i < bytes; ++i)
+      into->bitmaps[0][i] = 0b01011010;
+  }
+
+  return true;
+
+bad_format:
+  if (f)
+    close_file(f);
+  for (uint16_t i = 0; i < 256; ++i)
+    if (into->bitmaps[i])
+      free_block(into->bitmaps[i]);
+  return false;
+}
+\ No newline at end of file
diff --git a/src/user/libfont/bdf.h b/src/user/libfont/bdf.h
new file mode 100644
index 0000000..4ed4189
--- /dev/null
+++ b/src/user/libfont/bdf.h
@@ -0,0 +1,8 @@
+#ifndef LIBFONT_BDF_H
+#define LIBFONT_BDF_H
+
+#include <stdbool.h>
+
+bool try_load_bdf(const char *path, struct font_info *into);
+
+#endif
+\ No newline at end of file
diff --git a/src/user/libfont/filist.c b/src/user/libfont/filist.c
new file mode 100644
index 0000000..ae24429
--- /dev/null
+++ b/src/user/libfont/filist.c
@@ -0,0 +1,33 @@
+#include <libfont/fonts.h>
+#include <knob/block.h>
+#include <knob/heap.h>
+
+struct dict_entry {
+  char *name;
+  struct font_info *fi;
+  struct dict_entry *prev;
+} *last_entry = 0;
+
+__attribute__ ((pure))
+struct font_info *find_entry(const char *name) {
+  for (struct dict_entry *i = last_entry; i; i = i->prev)
+    if (strequ(i->name, name))
+      return i->fi;
+  return 0;
+}
+
+struct font_info *new_entry(const char *name) {
+  struct dict_entry *const nde = get_block(sizeof(struct dict_entry));
+  nde->name = strdup(name);
+  nde->fi = get_block(sizeof(struct font_info));
+  nde->prev = last_entry;
+  last_entry = nde;
+  return nde->fi;
+}
+
+void del_last() {//only called when last_entry isn't 0
+  free_block(last_entry->name);
+  free_block(last_entry->fi);
+  free_block(last_entry);
+  last_entry = last_entry->prev;
+}
+\ No newline at end of file
diff --git a/src/user/libfont/filist.h b/src/user/libfont/filist.h
new file mode 100644
index 0000000..c78c640
--- /dev/null
+++ b/src/user/libfont/filist.h
@@ -0,0 +1,8 @@
+#ifndef LIBFONT_FILIST_H
+#define LIBFONT_FILIST_H
+
+struct font_info *find_entry(const char *name) __attribute__ ((pure));
+struct font_info *new_entry(const char *name);
+void del_last();
+
+#endif
+\ No newline at end of file
diff --git a/src/user/libfont/fonts.c b/src/user/libfont/fonts.c
new file mode 100644
index 0000000..1692992
--- /dev/null
+++ b/src/user/libfont/fonts.c
@@ -0,0 +1,66 @@
+#include <libfont/fonts.h>
+#include <knob/format.h>
+#include <knob/block.h>
+#include <knob/heap.h>
+#include <knob/file.h>
+
+#include "filist.h"
+#include "bdf.h"
+
+#define FONT_PATH "fonts/"
+#define FONT_PATH_L 6
+
+struct font_loader_t {
+  const char *ext;
+  bool (*func)(const char *, struct font_info *);
+} font_loaders[] = {
+  { .ext = ".bdf",
+    .func = try_load_bdf
+  },
+  { .ext = ""
+  }
+};
+
+struct font_info *get_font(const char *name) {
+  struct font_info *font = find_entry(name);
+  if (font)
+    return font;
+  font = new_entry(name);
+  if (!font)
+    return 0;//out of memory?
+
+  const uint32_t name_len = strlen(name);
+  for (struct font_loader_t *i = font_loaders; i->ext[0]; ++i) {
+    char *buf = get_block(FONT_PATH_L + name_len + strlen(i->ext) + 1);
+    blockcpy(buf, FONT_PATH, FONT_PATH_L);
+    blockcpy(buf + FONT_PATH_L, name, name_len);
+    strcpy(buf + FONT_PATH_L + name_len, i->ext);
+    struct file *f = open_file(buf);
+    if (!f) {
+      free_block(buf);
+      continue;
+    }
+    syslogf("[libfont] Loading %s%s...", name, i->ext);
+    if (i->func(buf, font)) {
+      close_file(f);
+      free_block(buf);
+      syslogf("[libfont] Loaded %s%s.", name, i->ext);
+      return font;
+    }
+    close_file(f);
+    free_block(buf);
+    syslogf("[libfont] Failed to load %s%s.", name, i->ext);
+  }
+  del_last();
+  return 0;
+}
+
+void put_char(const struct font_info *font, char ch, uint8_t *pb_ptr, uint32_t pb_pitch, uint8_t bg, uint8_t fg) {
+//char *const msg = format("put_char(font = 0x%x, ch = '%c', pb_ptr = 0x%x, pb_pitch = %u, bg = 0x%2x, fg = 0x%2x);", font, ch, pb_ptr, pb_pitch, bg, fg);
+//_system_log(msg);
+//free_block(msg);
+  const bool *const bitmap = font->bitmaps[(uint8_t)ch] ? font->bitmaps[(uint8_t)ch] : font->bitmaps[0];
+  for (uint32_t y = 0; y < font->char_height; ++y)
+    for (uint32_t x = 0; x < font->char_width; ++x)
+      pb_ptr[y * pb_pitch + x] = bitmap[y * font->char_width + x] ? fg : bg;
+}
+\ No newline at end of file