puzzles: dynamic text size via custom font pack

Up to now, we'd just ignore whatever font size the puzzle asked for,
and instead just go with either the UI font or system font regardless
of their size, which led to some horrible-looking puzzles. This patch
adds the ability to automatically load fonts of the proper size when
they are available, which makes text-based puzzles such as Pattern and
Slant function correctly with any UI font.

The font pack, which should be extracted to the system-wide fonts
directory consists of 3 small bitmap fonts from 7px to 10px and then
anti-aliased Deja Vu fonts from 10px to 36px. It is available in the
source tree (apps/plugins/puzzles/fonts.zip), or from
<http://download.rockbox.org/useful/sgt-fonts.zip>.

Change-Id: I05c8fe7bd6d867e14de9b941deb91e8c642ee4a8

1 files changed, 137 insertions, 13 deletions

diff --git a/apps/plugins/puzzles/rockbox.c b/apps/plugins/puzzles/rockbox.c
index 56bb83e3a6..18194dad36 100644
--- a/apps/plugins/puzzles/rockbox.c
+++ b/apps/plugins/puzzles/rockbox.c
@@ -30,7 +30,9 @@
 #ifndef COMBINED
 #include "lib/playback_control.h"
 #endif
+#include "lib/simple_viewer.h"
 #include "lib/xlcd.h"
+
 #include "fixedpoint.h"
 
 /* how many ticks between timer callbacks */
@@ -131,28 +133,128 @@ static void rb_color(int n)
     rb->lcd_set_foreground(colors[n]);
 }
 
-static void rb_draw_text(void *handle, int x, int y, int fonttype,
-                         int fontsize, int align, int color, char *text)
+/* font bundle size range */
+#define BUNDLE_MIN 7
+#define BUNDLE_MAX 36
+#define BUNDLE_COUNT (BUNDLE_MAX - BUNDLE_MIN + 1)
+
+static struct bundled_font {
+    int status; /* -3 = never tried loading, or unloaded, -2 = failed to load, >= -1: loaded successfully */
+    int last_use;
+} loaded_fonts[2*BUNDLE_COUNT]; /* monospace are first, then proportional */
+
+static int n_fonts, access_counter = -1;
+
+static void unload_fonts(void)
 {
-    (void) fontsize;
-    LOGF("rb_draw_text(%d %d %s)", x, y, text);
+    for(int i = 0; i < 2 * BUNDLE_COUNT; ++i)
+        if(loaded_fonts[i].status > 0) /* don't unload FONT_UI */
+        {
+            rb->font_unload(loaded_fonts[i].status);
+            loaded_fonts[i].status = -3;
+        }
+    access_counter = -1;
+    rb->lcd_setfont(FONT_UI);
+}
 
-    offset_coords(&x, &y);
+static void rb_setfont(int type, int size)
+{
+    if(access_counter < 0)
+    {
+        for(int i = 0; i < 2 * BUNDLE_COUNT; ++i)
+                loaded_fonts[i].status = -3;
+        access_counter = 0;
+        n_fonts = 0;
+    }
+
+    /* out of range */
+    if(BUNDLE_MAX < size)
+        size = BUNDLE_MAX;
 
-    /* TODO: variable font size */
-    switch(fonttype)
+    int font_idx = (type == FONT_FIXED ? 0 : BUNDLE_COUNT) + size - BUNDLE_MIN;
+    switch(loaded_fonts[font_idx].status)
     {
-    case FONT_FIXED:
-        rb->lcd_setfont(FONT_SYSFIXED);
-        break;
-    case FONT_VARIABLE:
-        rb->lcd_setfont(FONT_UI);
+    case -3:
+    {
+        /* never loaded */
+        char buf[MAX_PATH];
+        if(size < 10) /* Deja Vu only goes down to 10px, below that it's a giant blob */
+        {
+            if(size < 7)
+                size = 7; /* we're not going to force anyone to read 05-Tiny :P */
+            /* we also don't care about monospace/proportional at this point */
+            switch(size)
+            {
+            case 7:
+                rb->snprintf(buf, sizeof(buf), FONT_DIR "/07-Fixed.fnt");
+                break;
+            case 8:
+                rb->snprintf(buf, sizeof(buf), FONT_DIR "/08-Rockfont.fnt");
+                break;
+            case 9:
+                rb->snprintf(buf, sizeof(buf), FONT_DIR "/09-Fixed.fnt");
+                break;
+            default:
+                assert(false);
+            }
+        }
+        else
+            rb->snprintf(buf, sizeof(buf), FONT_DIR "/%02d-%s.fnt", size, type == FONT_FIXED ? "DejaVuSansMono" : "DejaVuSans");
+
+        if(n_fonts >= MAXUSERFONTS - 3) /* safety margin, FIXME */
+        {
+            /* unload an old font */
+            int oldest_use = -1, oldest_idx = -1;
+            for(int i = 0; i < 2 * BUNDLE_COUNT; ++i)
+            {
+                if((loaded_fonts[i].status >= 0 && loaded_fonts[i].last_use < oldest_use) || oldest_use < 0)
+                {
+                    oldest_use = loaded_fonts[i].last_use;
+                    oldest_idx = i;
+                }
+            }
+            assert(oldest_idx >= 0);
+            rb->font_unload(loaded_fonts[oldest_idx].status);
+            loaded_fonts[oldest_idx].status = -3;
+            n_fonts--;
+        }
+
+        loaded_fonts[font_idx].status = rb->font_load(buf);
+        if(loaded_fonts[font_idx].status < 0)
+            goto fallback;
+        loaded_fonts[font_idx].last_use = access_counter++;
+        n_fonts++;
+        rb->lcd_setfont(loaded_fonts[font_idx].status);
         break;
+    }
+    case -2:
+    case -1:
+        goto fallback;
     default:
-        fatal("bad font");
+        loaded_fonts[font_idx].last_use = access_counter++;
+        rb->lcd_setfont(loaded_fonts[font_idx].status);
         break;
     }
 
+    return;
+
+fallback:
+
+    rb->lcd_setfont(type == FONT_FIXED ? FONT_SYSFIXED : FONT_UI);
+
+    return;
+}
+
+static void rb_draw_text(void *handle, int x, int y, int fonttype,
+                         int fontsize, int align, int color, char *text)
+{
+    (void) fontsize;
+    LOGF("rb_draw_text(%d %d %s)", x, y, text);
+
+    offset_coords(&x, &y);
+
+    rb_setfont(fonttype, fontsize);
+
     int w, h;
     rb->lcd_getstringsize(text, &w, &h);
 
@@ -1053,6 +1155,27 @@ static void quick_help(void)
     return;
 }
 
+static void full_help(const char *name)
+{
+    unsigned old_bg = rb->lcd_get_background();
+
+    bool orig_clipped = clipped;
+    if(orig_clipped)
+        rb_unclip(NULL);
+
+    rb->lcd_set_foreground(LCD_WHITE);
+    rb->lcd_set_background(LCD_BLACK);
+    unload_fonts();
+    rb->lcd_setfont(FONT_UI);
+
+    view_text(name, help_text);
+
+    rb->lcd_set_background(old_bg);
+
+    if(orig_clipped)
+        rb_clip(NULL, clip_rect.x, clip_rect.y, clip_rect.width, clip_rect.height);
+}
+
 static void init_default_settings(void)
 {
     settings.slowmo_factor = 1;
@@ -1663,6 +1786,7 @@ static char *init_for_game(const game *gm, int load_fd, bool draw)
 
 static void exit_handler(void)
 {
+    unload_fonts();
 #ifdef HAVE_ADJUSTABLE_CPU_FREQ
     rb->cpu_boost(false);
 #endif