add vgcanvas_get_text_metrics

docs/changes.md

@@ -3,7 +3,8 @@
 * 2020/06/30
   * 完善 font gen（感谢智明提供补丁）。
   * 完善 image dither（感谢大恒提供补丁）。
-  
+  * add vgcanvas\_get\_text\_metrics.
+
 * 2020/06/29
   * 完善 listview layout（感谢尧燊提供补丁）
 	* 完善 input\_type\_to\_keyboard\_name（感谢俊杰提供补丁）

src/base/canvas.c

@@ -1799,3 +1799,25 @@ ret_t canvas_reset(canvas_t* c) {
 
   return RET_OK;
 }
+
+ret_t canvas_get_text_metrics(canvas_t* c, float_t* ascent, float_t* descent,
+                              float_t* line_hight) {
+  return_value_if_fail(c!= NULL, RET_BAD_PARAMS);
+  return_value_if_fail(ascent != NULL && descent != NULL && line_hight != NULL, RET_BAD_PARAMS);
+
+  if(c->lcd != NULL && c->lcd->get_text_metrics != NULL) {
+    return c->lcd->get_text_metrics(c->lcd, ascent, descent, line_hight);
+  } else if(c->font != NULL) {
+    font_vmetrics_t vmetrics = font_get_vmetrics(c->font, c->font_size);
+
+    *ascent = vmetrics.ascent;
+    *descent = vmetrics.descent;
+    *line_hight = vmetrics.line_gap + vmetrics.ascent + vmetrics.descent;
+    return RET_OK;
+  } else {
+    *ascent = 0;
+    *descent = 0;
+    *line_hight = 0;
+    return RET_FAIL;
+  }
+}

src/base/canvas.h

@@ -690,6 +690,20 @@ ret_t canvas_set_font_manager(canvas_t* c, font_manager_t* font_manager);
  */
 ret_t canvas_set_assets_manager(canvas_t* c, assets_manager_t* assets_manager);
 
+/**
+ * @method canvas_get_text_metrics
+ * 获取当前字体的度量信息。
+ *
+ * @param {canvas_t*} canvas canvas对象。
+ * @param {float_t*} ascent 用于返回ascent。
+ * @param {float_t*} descent 用于返回descent。
+ * @param {float_t*} line_hight 用于返回line height。
+ *
+ * @return {ret_t} 返回RET_OK表示成功，否则表示失败。
+ */
+ret_t canvas_get_text_metrics(canvas_t* canvas, float_t* ascent, 
+                                      float_t* descent, float_t* line_hight);
+
 /**
  * @method canvas_begin_frame
  * 绘制开始。

src/base/lcd.c

@@ -320,3 +320,11 @@ wh_t lcd_get_height(lcd_t* lcd) {
     return lcd->h;
   }
 }
+
+ret_t lcd_get_text_metrics(lcd_t* lcd, float_t* ascent, 
+                                      float_t* descent, float_t* line_hight) {
+  return_value_if_fail(lcd != NULL && lcd->get_text_metrics != NULL, RET_BAD_PARAMS);
+
+  return lcd->get_text_metrics(lcd, ascent, descent, line_hight);
+}
+

src/base/lcd.h

@@ -45,6 +45,8 @@ typedef ret_t (*lcd_begin_frame_t)(lcd_t* lcd, rect_t* dirty_rect);
 typedef ret_t (*lcd_set_clip_rect_t)(lcd_t* lcd, rect_t* rect);
 typedef ret_t (*lcd_get_clip_rect_t)(lcd_t* lcd, rect_t* rect);
 typedef ret_t (*lcd_resize_t)(lcd_t* lcd, wh_t w, wh_t h, uint32_t line_length);
+typedef ret_t (*lcd_get_text_metrics_t)(lcd_t* lcd, float_t* ascent, 
+                                      float_t* descent, float_t* line_hight);
 
 typedef ret_t (*lcd_set_global_alpha_t)(lcd_t* lcd, uint8_t alpha);
 typedef ret_t (*lcd_set_text_color_t)(lcd_t* lcd, color_t color);
@@ -164,6 +166,7 @@ struct _lcd_t {
   lcd_set_fill_color_t set_fill_color;
   lcd_set_font_name_t set_font_name;
   lcd_set_font_size_t set_font_size;
+  lcd_get_text_metrics_t get_text_metrics;
   lcd_draw_vline_t draw_vline;
   lcd_draw_hline_t draw_hline;
   lcd_fill_rect_t fill_rect;
@@ -608,6 +611,20 @@ bool_t lcd_is_swappable(lcd_t* lcd);
  */
 ret_t lcd_end_frame(lcd_t* lcd);
 
+/**
+ * @method lcd_get_text_metrics
+ * 获取当前字体的度量信息。
+ *
+ * @param {lcd_t*} lcd lcd对象。
+ * @param {float_t*} ascent 用于返回ascent。
+ * @param {float_t*} descent 用于返回descent。
+ * @param {float_t*} line_hight 用于返回line height。
+ *
+ * @return {ret_t} 返回RET_OK表示成功，否则表示失败。
+ */
+ret_t lcd_get_text_metrics(lcd_t* lcd, float_t* ascent, 
+                                      float_t* descent, float_t* line_hight);
+
 /**
  * @method lcd_destroy
  * 销毁lcd对象。

src/base/vgcanvas.c

@@ -510,3 +510,12 @@ wh_t vgcanvas_get_height(vgcanvas_t* vgcanvas) {
     return vgcanvas->h;
   }
 }
+
+ret_t vgcanvas_get_text_metrics(vgcanvas_t* vg, float_t* ascent, 
+                                      float_t* descent, float_t* line_hight) {
+  return_value_if_fail(vg != NULL && vg->vt != NULL, RET_BAD_PARAMS);
+  return_value_if_fail(vg->vt->get_text_metrics != NULL, RET_BAD_PARAMS);
+
+  return vg->vt->get_text_metrics(vg, ascent, descent, line_hight);
+}
+

src/base/vgcanvas.h

@@ -86,6 +86,8 @@ typedef ret_t (*vgcanvas_set_font_t)(vgcanvas_t* vg, const char* font);
 typedef ret_t (*vgcanvas_set_font_size_t)(vgcanvas_t* vg, float_t size);
 typedef ret_t (*vgcanvas_set_text_align_t)(vgcanvas_t* vg, const char* value);
 typedef ret_t (*vgcanvas_set_text_baseline_t)(vgcanvas_t* vg, const char* value);
+typedef ret_t (*vgcanvas_get_text_metrics_t)(vgcanvas_t* vg, float_t* ascent, 
+                                      float_t* descent, float_t* line_hight);
 typedef ret_t (*vgcanvas_fill_text_t)(vgcanvas_t* vg, const char* text, float_t x, float_t y,
                                       float_t max_width);
 typedef float_t (*vgcanvas_measure_text_t)(vgcanvas_t* vg, const char* text);
@@ -169,6 +171,7 @@ typedef struct _vgcanvas_vtable_t {
   vgcanvas_set_font_size_t set_font_size;
   vgcanvas_set_text_align_t set_text_align;
   vgcanvas_set_text_baseline_t set_text_baseline;
+  vgcanvas_get_text_metrics_t get_text_metrics;
   vgcanvas_fill_text_t fill_text;
   vgcanvas_measure_text_t measure_text;
   vgcanvas_draw_image_t draw_image;
@@ -853,6 +856,20 @@ ret_t vgcanvas_set_text_align(vgcanvas_t* vg, const char* value);
  */
 ret_t vgcanvas_set_text_baseline(vgcanvas_t* vg, const char* value);
 
+/**
+ * @method vgcanvas_get_text_metrics
+ * 获取当前字体的度量信息。
+ *
+ * @param {vgcanvas_t*} vg vgcanvas对象。
+ * @param {float_t*} ascent 用于返回ascent。
+ * @param {float_t*} descent 用于返回descent。
+ * @param {float_t*} line_hight 用于返回line height。
+ *
+ * @return {ret_t} 返回RET_OK表示成功，否则表示失败。
+ */
+ret_t vgcanvas_get_text_metrics(vgcanvas_t* vg, float_t* ascent, 
+                                      float_t* descent, float_t* line_hight);
+
 /**
  * @method vgcanvas_fill_text
  * 绘制文本。

src/lcd/lcd_vgcanvas.inc

@@ -251,6 +251,12 @@ static bitmap_format_t lcd_vgcanvas_get_desired_bitmap_format(lcd_t* lcd) {
   return BITMAP_FMT_RGBA8888;
 }
 
+static ret_t lcd_vgcanvas_get_text_metrics(lcd_t* lcd, float_t* ascender, 
+                                      float_t* descender, float_t* lineh) {
+  vgcanvas_t* canvas = LCD(lcd)->canvas;
+  return vgcanvas_get_text_metrics(canvas, ascender, descender, lineh);
+}
+
 lcd_t* lcd_vgcanvas_init(wh_t w, wh_t h, vgcanvas_t* canvas) {
   lcd_vgcanvas_t* lcd = TKMEM_ZALLOC(lcd_vgcanvas_t);
   lcd_t* base = &(lcd->base);
@@ -279,7 +285,7 @@ lcd_t* lcd_vgcanvas_init(wh_t w, wh_t h, vgcanvas_t* canvas) {
   base->get_width = lcd_vgcanvas_get_width;
   base->get_height = lcd_vgcanvas_get_height;
   base->destroy = lcd_vgcanvas_destroy;
-
+  base->get_text_metrics = lcd_vgcanvas_get_text_metrics;
   base->w = (wh_t)w;
   base->h = (wh_t)h;
   base->ratio = canvas->ratio;

src/vgcanvas/vgcanvas_nanovg.inc

@@ -393,6 +393,31 @@ static float_t vgcanvas_nanovg_measure_text(vgcanvas_t* vgcanvas, const char* te
   return nvgTextBounds(vg, 0, 0, text, text + strlen(text), bounds);
 }
 
+static ret_t vgcanvas_nanovg_get_text_metrics(vgcanvas_t* vgcanvas, float_t* ascent, 
+                                      float_t* descent, float_t* line_hight) {
+  NVGcontext* vg = ((vgcanvas_nanovg_t*)vgcanvas)->vg;
+
+  float a = 0;
+  float  d = 0;
+  float  h = 0;
+
+  nvgTextMetrics(vg, &a, &d, &h);
+
+  if(ascent != NULL) {
+    *ascent = a;
+  }
+
+  if(descent != NULL) {
+    *descent = d;
+  }
+
+  if(line_hight != NULL) {
+    *line_hight = h;
+  }
+
+  return RET_OK;
+}
+
 static ret_t vgcanvas_nanovg_draw_image(vgcanvas_t* vgcanvas, bitmap_t* img, float_t sx, float_t sy,
                                         float_t sw, float_t sh, float_t dx, float_t dy, float_t dw,
                                         float_t dh) {
@@ -616,6 +641,7 @@ static const vgcanvas_vtable_t vt = {
     .set_line_join = vgcanvas_nanovg_set_line_join,
     .set_line_cap = vgcanvas_nanovg_set_line_cap,
     .set_miter_limit = vgcanvas_nanovg_set_miter_limit,
+    .get_text_metrics = vgcanvas_nanovg_get_text_metrics,
     .save = vgcanvas_nanovg_save,
     .restore = vgcanvas_nanovg_restore,
     .end_frame = vgcanvas_nanovg_end_frame,