PicoVector: Text wrap support.

libraries/pico_vector/alright_fonts.cpp

@@ -11,6 +11,19 @@
 using namespace pretty_poly;
 
 namespace alright_fonts {
+  /*
+    utility functions
+  */
+  pretty_poly::rect_t measure_character(text_metrics_t &tm, uint16_t codepoint) {
+    if(tm.face.glyphs.count(codepoint) == 1) {
+      glyph_t glyph = tm.face.glyphs[codepoint];
+
+      return {0, 0, ((glyph.advance * tm.size) / 128), tm.size};
+    }
+
+    return {0, 0, 0, 0};
+  }
+
   /*
     render functions
   */

libraries/pico_vector/alright_fonts.hpp

@@ -52,14 +52,19 @@ namespace alright_fonts {
 
     void set_size(int s) {
       size = s;
-      line_height = size * 1.2;
+      line_height = size;
       letter_spacing = 0;
-      word_spacing = size;
+      word_spacing = size / 2;
     }
 
     text_metrics_t() {};
   };
 
+  /*
+    utility functions
+  */
+  pretty_poly::rect_t measure_character(text_metrics_t &tm, uint16_t codepoint);
+
   /* 
     render functions
   */

libraries/pico_vector/pico_vector.cpp

@@ -13,16 +13,56 @@ namespace pimoroni {
     // TODO: Normalize types somehow, so we're not converting?
     pretty_poly::point_t<int> caret = pretty_poly::point_t<int>(origin.x, origin.y);
 
-    for (auto c : text) {
-        alright_fonts::render_character(text_metrics, c, caret);
-        if(text_metrics.face.glyphs.count(c) == 1) {
-            alright_fonts::glyph_t glyph = text_metrics.face.glyphs[c];
-            caret.x += ((glyph.advance * text_metrics.size) / 128);
-            if(caret.x > graphics->bounds.w) {
-                caret.y += text_metrics.size;
-                caret.x = origin.x;
-            }
+    // Align text from the bottom left
+    caret.y += text_metrics.size;
+
+    int16_t space_width = alright_fonts::measure_character(text_metrics, ' ').w;
+    if (space_width == 0) {
+      space_width = text_metrics.word_spacing;
+    }
+
+    size_t i = 0;
+
+    while(i < text.length()) {
+      size_t next_space = text.find(' ', i + 1);
+
+      if(next_space == std::string::npos) {
+        next_space = text.length();
+      }
+
+      size_t next_linebreak = text.find('\n', i + 1);
+
+      if(next_linebreak == std::string::npos) {
+        next_linebreak = text.length();
+      }
+
+      size_t next_break = std::min(next_space, next_linebreak);
+
+      uint16_t word_width = 0;
+      for(size_t j = i; j < next_break; j++) {
+        word_width += alright_fonts::measure_character(text_metrics, text[j]).w;
+        word_width += text_metrics.letter_spacing;
+      }
+
+      if(caret.x != 0 && caret.x + word_width > graphics->clip.w) {
+        caret.x = 0;
+        caret.y += text_metrics.line_height;
+      }
+
+      for(size_t j = i; j < std::min(next_break + 1, text.length()); j++) {
+        if (text[j] == '\n') { // Linebreak
+          caret.x = 0;
+          caret.y += text_metrics.line_height;
+        } else if (text[j] == ' ') { // Space
+          caret.x += space_width;
+        } else {
+          alright_fonts::render_character(text_metrics, text[j], caret);
         }
+        caret.x += alright_fonts::measure_character(text_metrics, text[j]).w;
+        caret.x += text_metrics.letter_spacing;
+      }
+
+      i = next_break + 1;
     }
 
     return Point(caret.x, caret.y);

libraries/pico_vector/pico_vector.hpp

@@ -21,7 +21,7 @@ namespace pimoroni {
                             }
                         }
                     }
-                }, pretty_poly::NONE, {0, 0, graphics->bounds.w, graphics->bounds.h});
+                }, pretty_poly::X4, {0, 0, graphics->bounds.w, graphics->bounds.h});
             };
 
             bool set_font(std::string_view font_path, unsigned int font_size) {