Small improvements to rotated font rendering

Author: MichaelBell

libraries/pico_vector/alright_fonts.cpp

@@ -41,7 +41,8 @@ namespace alright_fonts {
     }
   }
 
-  void render_character(text_metrics_t &tm, uint16_t codepoint, pretty_poly::point_t<int> origin, pretty_poly::mat3_t transform) {
+  template<typename mat_t>
+  void render_character(text_metrics_t &tm, uint16_t codepoint, pretty_poly::point_t<int> origin, mat_t transform) {
     if(tm.face.glyphs.count(codepoint) == 1) {
       glyph_t glyph = tm.face.glyphs[codepoint];
 
@@ -51,26 +52,35 @@ namespace alright_fonts {
       unsigned scale = tm.size << 9;
 
       std::vector<pretty_poly::contour_t<int8_t>> contours;
+      contours.reserve(glyph.contours.size());
 
+      unsigned int total_points = 0;
       for(auto i = 0u; i < glyph.contours.size(); i++) {
-        unsigned int count = glyph.contours[i].count;
-        point_t<int8_t> *points = (point_t<int8_t> *)malloc(sizeof(point_t<int8_t>) * count);
+        total_points += glyph.contours[i].count;;
+      }
+
+      point_t<int8_t> *points = (point_t<int8_t> *)malloc(sizeof(point_t<int8_t>) * total_points);
+
+      for(auto i = 0u; i < glyph.contours.size(); i++) {
+        const unsigned int count = glyph.contours[i].count;
         for(auto j = 0u; j < count; j++) {
           point_t<float> point(glyph.contours[i].points[j].x, glyph.contours[i].points[j].y);
           point *= transform;
           points[j] = point_t<int8_t>(point.x, point.y);
         }
         contours.emplace_back(points, count);
+        points += count;
       }
 
       pretty_poly::draw_polygon<int8_t>(contours, origin, scale);
 
-      for(auto contour : contours) {
-        free(contour.points);
-      }
+      free(contours[0].points);
     }
   }
 
+  template void render_character<pretty_poly::mat3_t>(text_metrics_t &tm, uint16_t codepoint, pretty_poly::point_t<int> origin, pretty_poly::mat3_t transform);
+  template void render_character<pretty_poly::mat2_t>(text_metrics_t &tm, uint16_t codepoint, pretty_poly::point_t<int> origin, pretty_poly::mat2_t transform);
+
   /*
     load functions
   */

libraries/pico_vector/alright_fonts.hpp

@@ -70,5 +70,6 @@ namespace alright_fonts {
   */
 
   void render_character(text_metrics_t &tm, uint16_t codepoint, pretty_poly::point_t<int> origin);
-  void render_character(text_metrics_t &tm, uint16_t codepoint, pretty_poly::point_t<int> origin, pretty_poly::mat3_t transform);
+  template<typename mat_t>
+  void render_character(text_metrics_t &tm, uint16_t codepoint, pretty_poly::point_t<int> origin, mat_t transform);
 }

libraries/pico_vector/pico_vector.cpp

@@ -114,7 +114,7 @@ namespace pimoroni {
 
     // Prepare a transformation matrix for character and offset rotation
     angle = (2 * (float)M_PI / 360.f) * angle;
-    pretty_poly::mat3_t transform = pretty_poly::mat3_t::rotation(angle);
+    pretty_poly::mat2_t transform = pretty_poly::mat2_t::rotation(angle);
 
     // Align text from the bottom left
     caret.y += text_metrics.line_height;

libraries/pico_vector/pretty_poly.cpp

@@ -252,7 +252,7 @@ namespace pretty_poly {
   }
 
   template<typename T>
-  void draw_polygon(std::vector<contour_t<T>> contours, point_t<int> origin, int scale) {    
+  void draw_polygon(const std::vector<contour_t<T>>& contours, point_t<int> origin, int scale) {    
 
     debug("> draw polygon with %lu contours\n", contours.size());
 
@@ -306,7 +306,7 @@ namespace pretty_poly {
         memset(tile.data, 0, tile_buffer_size);
 
         // build the nodes for each contour
-        for(contour_t<T> &contour : contours) {
+        for(const contour_t<T> &contour : contours) {
           debug("    : build nodes for contour\n");
           build_nodes(contour, tile, origin, scale);
         }
@@ -333,7 +333,7 @@ namespace pretty_poly {
   }
 }
 
-template void pretty_poly::draw_polygon<int>(std::vector<contour_t<int>> contours, point_t<int> origin, int scale);
-template void pretty_poly::draw_polygon<float>(std::vector<contour_t<float>> contours, point_t<int> origin, int scale);
-template void pretty_poly::draw_polygon<uint8_t>(std::vector<contour_t<uint8_t>> contours, point_t<int> origin, int scale);
-template void pretty_poly::draw_polygon<int8_t>(std::vector<contour_t<int8_t>> contours, point_t<int> origin, int scale);
+template void pretty_poly::draw_polygon<int>(const std::vector<contour_t<int>>& contours, point_t<int> origin, int scale);
+template void pretty_poly::draw_polygon<float>(const std::vector<contour_t<float>>& contours, point_t<int> origin, int scale);
+template void pretty_poly::draw_polygon<uint8_t>(const std::vector<contour_t<uint8_t>>& contours, point_t<int> origin, int scale);
+template void pretty_poly::draw_polygon<int8_t>(const std::vector<contour_t<int8_t>>& contours, point_t<int> origin, int scale);

libraries/pico_vector/pretty_poly.hpp

@@ -68,5 +68,5 @@ namespace pretty_poly {
   void draw_polygon(T *points, unsigned count);
 
   template<typename T>
-  void draw_polygon(std::vector<contour_t<T>> contours, point_t<int> origin = point_t<int>(0, 0), int scale = 65536);
+  void draw_polygon(const std::vector<contour_t<T>>& contours, point_t<int> origin = point_t<int>(0, 0), int scale = 65536);
 }

libraries/pico_vector/pretty_poly_types.hpp

@@ -145,7 +145,7 @@ namespace pretty_poly {
     //point_t<T> *begin() const { return points; };
     //point_t<T> *end() const { return points + count * sizeof(point_t<T>); };
 
-    rect_t bounds() {
+    rect_t bounds() const {
       T minx = this->points[0].x, maxx = minx;
       T miny = this->points[0].y, maxy = miny;
       for(auto i = 1u; i < this->count; i++) {