From 6a9bc8688fcbbd294c3b711867dc7c3264831f52 Mon Sep 17 00:00:00 2001
From: Phil Howard <phil@gadgetoid.com>
Date: Thu, 31 Mar 2022 18:09:50 +0100
Subject: [PATCH] Bitmap Fonts: Add accent rendering.

Render accents above and below the 64 characters > 127.

Different offsets for upper/lower case characters.
---
 common/unicode_sorta.hpp                  |  6 +++-
 libraries/bitmap_fonts/bitmap_fonts.cpp   | 37 ++++++++++++++++++++---
 libraries/bitmap_fonts/bitmap_fonts.hpp   |  3 ++
 libraries/bitmap_fonts/font6_data.hpp     | 14 ++++++++-
 libraries/bitmap_fonts/font8_data.hpp     | 14 ++++++++-
 libraries/hershey_fonts/hershey_fonts.cpp |  5 +--
 6 files changed, 67 insertions(+), 12 deletions(-)

diff --git a/common/unicode_sorta.hpp b/common/unicode_sorta.hpp
index 7dc77e0f..0022e2d8 100644
--- a/common/unicode_sorta.hpp
+++ b/common/unicode_sorta.hpp
@@ -9,6 +9,8 @@ It permits rudimentary support for unicode characters by providing a lookup
 table to map anything prefixed with 0xc3 to its non-accented equivilent.
 */
 
+namespace unicode_sorta {
+
 const uint8_t UNICODE_PREFIX = 0xc3;
 
 enum accents : uint8_t {
@@ -155,4 +157,6 @@ static const char char_base[] = {
     'y', // ý - c3 bd - Y + ACUTE
     ' ', // þ - c3 be - THORN
     'y', // ÿ - c3 bf - Y + DIAERESIS
-};
\ No newline at end of file
+};
+
+}
\ No newline at end of file
diff --git a/libraries/bitmap_fonts/bitmap_fonts.cpp b/libraries/bitmap_fonts/bitmap_fonts.cpp
index e20d93a0..da509e9d 100644
--- a/libraries/bitmap_fonts/bitmap_fonts.cpp
+++ b/libraries/bitmap_fonts/bitmap_fonts.cpp
@@ -10,7 +10,7 @@ namespace bitmap {
     uint8_t char_index = c;
 
     if(char_index > 127) {
-      char_index = char_base[c - 128];
+      char_index = unicode_sorta::char_base[c - 128];
     }
 
     char_index -= 32;
@@ -32,22 +32,49 @@ namespace bitmap {
     }
 
     uint8_t char_index = c;
+    unicode_sorta::accents char_accent = unicode_sorta::ACCENT_NONE;
 
     if(char_index > 127) {
-      char_index = char_base[c - 128];
+      char_index = unicode_sorta::char_base[c - 128];
+      char_accent = unicode_sorta::char_accent[c - 128];
     }
 
+    bool upper = char_index < 97; // Only valid for A-Z and a-z
     char_index -= 32;
 
     const uint8_t *d = &font->data[char_index * font->max_width];
+    const uint8_t *a = &font->data[96 * font->max_width + char_accent * font->max_width];
+
+    // Vertical offset of our char within the 32 pixel column canvas
+    // At 16 pixels this gives us 8 pixels above and below the char for accents and spacing.
+    uint8_t offset = (32 - font->height) / 2;
+
     for(uint8_t cx = 0; cx < font->widths[char_index]; cx++) {
-      for(uint8_t cy = 0; cy < font->height; cy++) {
-        if((1U << cy) & *d) {
-          rectangle(x + (cx * scale), y + (cy * scale), scale, scale);
+      // Our maximum bitmap font height will be 16 pixels
+      // give ourselves a 32 pixel high canvas in which to plot the char and accent.
+      uint32_t data = *d << offset;
+      if(char_accent != unicode_sorta::ACCENT_NONE) {
+        uint32_t accent = *a;
+        accent <<= offset; // Shift the char to the middle of the canvas
+        if(char_accent == unicode_sorta::ACCENT_CEDILLA) {
+          // Special case handling for the Cedilla- that little upside-down question mark that goes beneath characters
+          accent <<= font->accent_offset_below;
+        } else {
+          accent >>= upper ? font->accent_offset_upper : font->accent_offset_lower; // Shift the accent above the char
+        }
+        data |= accent; // Merge the accent data into the canvas
+      }
+      // Offset our y position to account for our column canvas being 32 pixels
+      int y_offset = y - (offset * scale);
+      // Dra the 32 pixel high column
+      for(uint8_t cy = 0; cy < 32; cy++) {
+        if((1U << cy) & data) {
+          rectangle(x + (cx * scale), y_offset + (cy * scale), scale, scale);
         }
       }
 
       d++;
+      a++;
     }
   }
 
diff --git a/libraries/bitmap_fonts/bitmap_fonts.hpp b/libraries/bitmap_fonts/bitmap_fonts.hpp
index 432cafd7..c175eb1c 100644
--- a/libraries/bitmap_fonts/bitmap_fonts.hpp
+++ b/libraries/bitmap_fonts/bitmap_fonts.hpp
@@ -8,6 +8,9 @@ namespace bitmap {
   struct font_t {
     const uint8_t height;
     const uint8_t max_width;
+    const uint8_t accent_offset_upper; // Number of pixels to shift accents UP above uppercase letters
+    const uint8_t accent_offset_lower; // Number of pixels to shift accents UP above lowercase letters
+    const uint8_t accent_offset_below; // Number of pixels to shift accents DOWN below lowercase letters (height of the cedilla accent)
     const uint8_t widths[96];
     const uint8_t data[];
   };
diff --git a/libraries/bitmap_fonts/font6_data.hpp b/libraries/bitmap_fonts/font6_data.hpp
index 7b199476..c270c5f5 100644
--- a/libraries/bitmap_fonts/font6_data.hpp
+++ b/libraries/bitmap_fonts/font6_data.hpp
@@ -5,6 +5,9 @@
 const bitmap::font_t font6 {
   .height = 6,
   .max_width = 6,
+  .accent_offset_upper = 2,
+  .accent_offset_lower = 2,
+  .accent_offset_below = 2,
   .widths = {
     3, 2, 4, 6, 6, 6, 7, 2, 3, 3, 4, 4, 2, 4, 2, 4,
     6, 3, 5, 5, 6, 5, 6, 6, 6, 6, 2, 2, 4, 4, 4, 5,
@@ -109,6 +112,15 @@ const bitmap::font_t font6 {
     0x3e,0x00,0x00,0x00,0x00,0x00, // |
     0x22,0x3e,0x08,0x00,0x00,0x00, // }
     0x04,0x02,0x02,0x00,0x00,0x00, // ~
-    0x00,0x00,0x00,0x00,0x00,0x00
+    0x00,0x00,0x00,0x00,0x00,0x00,
+    // Accents
+    0x00,0x00,0x01,0x02,0x00,0x00, // Grave
+    0x00,0x00,0x02,0x01,0x00,0x00, // Acute
+    0x00,0x02,0x01,0x02,0x00,0x00, // Circumflex
+    0x00,0x01,0x02,0x01,0x02,0x00, // Tilde
+    0x00,0x01,0x00,0x01,0x00,0x00, // Diaresis
+    0x00,0x06,0x09,0x06,0x00,0x00, // Ring Above
+    0x00,0x40,0x20,0x10,0x00,0x00, // Stroke
+    0x00,0x00,0x28,0x10,0x00,0x00  // Cedilla
   }
 };
\ No newline at end of file
diff --git a/libraries/bitmap_fonts/font8_data.hpp b/libraries/bitmap_fonts/font8_data.hpp
index ad9601dc..e0a6212f 100644
--- a/libraries/bitmap_fonts/font8_data.hpp
+++ b/libraries/bitmap_fonts/font8_data.hpp
@@ -5,6 +5,9 @@
 const bitmap::font_t font8 {
   .height = 8,
   .max_width = 6,
+  .accent_offset_upper = 2,
+  .accent_offset_lower = 1,
+  .accent_offset_below = 1,
   .widths = {
     2, 2, 4, 6, 5, 5, 5, 2, 4, 4, 4, 4, 3, 4, 3, 5,
     5, 4, 5, 5, 5, 5, 5, 5, 5, 5, 2, 3, 4, 4, 4, 5,
@@ -109,6 +112,15 @@ const bitmap::font_t font8 {
     0x7f,0x00,0x00,0x00,0x00,0x00, // |
     0x41,0x3e,0x08,0x00,0x00,0x00, // }
     0x08,0x04,0x08,0x04,0x00,0x00, // ~
-    0x00,0x00,0x00,0x00,0x00,0x00
+    0x00,0x00,0x00,0x00,0x00,0x00,
+    // Accents
+    0x00,0x00,0x01,0x02,0x00,0x00, // Grave
+    0x00,0x00,0x02,0x01,0x00,0x00, // Acute
+    0x00,0x02,0x01,0x02,0x00,0x00, // Circumflex
+    0x00,0x01,0x02,0x01,0x02,0x00, // Tilde
+    0x00,0x01,0x00,0x01,0x00,0x00, // Diaresis
+    0x00,0x06,0x09,0x06,0x00,0x00, // Ring Above
+    0x00,0x40,0x20,0x00,0x00,0x00, // Stroke
+    0x00,0x00,0xa0,0x40,0x00,0x00  // Cedilla
   }
 };
\ No newline at end of file
diff --git a/libraries/hershey_fonts/hershey_fonts.cpp b/libraries/hershey_fonts/hershey_fonts.cpp
index 56c0d8c1..7136ba1f 100644
--- a/libraries/hershey_fonts/hershey_fonts.cpp
+++ b/libraries/hershey_fonts/hershey_fonts.cpp
@@ -24,7 +24,7 @@ namespace hershey {
     }
 
     if(c > 127) {
-      c = char_base[c - 128];
+      c = unicode_sorta::char_base[c - 128];
     }
 
     return &font->chars[c - 32];
@@ -50,9 +50,6 @@ namespace hershey {
   }
 
   int32_t glyph(const font_t* font, line_func line, unsigned char c, int32_t x, int32_t y, float s, float a) {
-    if (c == UNICODE_PREFIX) {
-      return 0;
-    }
     const font_glyph_t *gd = glyph_data(font, c);
 
     // if glyph data not found (id too great) then skip