fix(draw): center imgfont's drawing position (#3668)

Signed-off-by: pengyiqiang <pengyiqiang@xiaomi.com>
Co-authored-by: pengyiqiang <pengyiqiang@xiaomi.com>
Co-authored-by: Gabor Kiss-Vamosi <kisvegabor@gmail.com>
Co-authored-by: W-Mai <1341398182@qq.com>

examples/others/imgfont/lv_example_imgfont_1.c

@@ -7,10 +7,11 @@
 LV_IMG_DECLARE(emoji_F617)
 static bool get_imgfont_path(const lv_font_t * font, void * img_src,
                              uint16_t len, uint32_t unicode, uint32_t unicode_next,
-                             void * user_data)
+                             lv_coord_t * offset_y, void * user_data)
 {
     LV_UNUSED(font);
     LV_UNUSED(unicode_next);
+    LV_UNUSED(offset_y);
     LV_UNUSED(user_data);
     LV_ASSERT_NULL(img_src);
 
@@ -22,11 +23,10 @@ static bool get_imgfont_path(const lv_font_t * font, void * img_src,
     else {
         char * path = (char *)img_src;
 #if LV_USE_FFMPEG
-        snprintf(path, len, "%s/%04X.%s", "lvgl/examples/assets/emoji", unicode, "png");
+        lv_snprintf(path, len, "%s/%04X.png", "lvgl/examples/assets/emoji", unicode);
 #elif LV_USE_PNG
-        snprintf(path, len, "%s/%04X.%s", "A:lvgl/examples/assets/emoji", unicode, "png");
+        lv_snprintf(path, len, "%s/%04X.png", "A:lvgl/examples/assets/emoji", unicode);
 #endif
-        path[len - 1] = '\0';
     }
 
     return true;
@@ -40,6 +40,7 @@ void lv_example_imgfont_1(void)
     lv_font_t * imgfont = lv_imgfont_create(80, get_imgfont_path, NULL);
     if(imgfont == NULL) {
         LV_LOG_ERROR("imgfont init error");
+        return;
     }
 
     imgfont->fallback = LV_FONT_DEFAULT;

examples/others/imgfont/lv_example_imgfont_1.py

@@ -14,7 +14,7 @@ try:
 except NameError: 
     script_path = ''
     
-def get_imgfont_path(font, img_src, length, unicode, unicode_next,user_data) :
+def get_imgfont_path(font, img_src, length, unicode, unicode_next, offset_y, user_data) :
     if unicode < 0xf600:
         return
     if LV_USE_FFMPEG:
@@ -31,6 +31,7 @@ def get_imgfont_path(font, img_src, length, unicode, unicode_next,user_data) :
 imgfont = lv.imgfont_create(80, get_imgfont_path, None)
 if imgfont == None:
     print("imgfont init error")
+    sys.exit(1)
 
 imgfont.fallback = LV_FONT_DEFAULT
 

src/draw/sw/lv_draw_sw_letter.c

@@ -130,9 +130,21 @@ void lv_draw_sw_letter(lv_draw_ctx_t * draw_ctx, const lv_draw_label_dsc_t * dsc
     /*Don't draw anything if the character is empty. E.g. space*/
     if((g.box_h == 0) || (g.box_w == 0)) return;
 
+    lv_coord_t real_h;
+#if LV_USE_IMGFONT
+    if(g.bpp == LV_IMGFONT_BPP) {
+        /*Center imgfont's drawing position*/
+        real_h = (dsc->font->line_height - g.box_h) / 2;
+    }
+    else
+#endif
+    {
+        real_h = (dsc->font->line_height - dsc->font->base_line) - g.box_h;
+    }
+
     lv_point_t gpos;
     gpos.x = pos_p->x + g.ofs_x;
-    gpos.y = pos_p->y + (dsc->font->line_height - dsc->font->base_line) - g.box_h - g.ofs_y;
+    gpos.y = pos_p->y + real_h - g.ofs_y;
 
     /*If the letter is completely out of mask don't draw it*/
     if(gpos.x + g.box_w < draw_ctx->clip_area->x1 ||

src/others/imgfont/lv_imgfont.c

@@ -19,7 +19,7 @@
  **********************/
 typedef struct {
     lv_font_t * font;
-    lv_get_imgfont_path_cb_t path_cb;
+    lv_imgfont_get_path_cb_t path_cb;
     void * user_data;
     char path[LV_IMGFONT_PATH_MAX_LEN];
 } imgfont_dsc_t;
@@ -46,7 +46,7 @@ static bool imgfont_get_glyph_dsc(const lv_font_t * font, lv_font_glyph_dsc_t *
 /**********************
  *   GLOBAL FUNCTIONS
  **********************/
-lv_font_t * lv_imgfont_create(uint16_t height, lv_get_imgfont_path_cb_t path_cb, void * user_data)
+lv_font_t * lv_imgfont_create(uint16_t height, lv_imgfont_get_path_cb_t path_cb, void * user_data)
 {
     LV_ASSERT_MSG(LV_IMGFONT_PATH_MAX_LEN > sizeof(lv_img_dsc_t),
                   "LV_IMGFONT_PATH_MAX_LEN must be greater than sizeof(lv_img_dsc_t)");
@@ -75,9 +75,7 @@ lv_font_t * lv_imgfont_create(uint16_t height, lv_get_imgfont_path_cb_t path_cb,
 
 void lv_imgfont_destroy(lv_font_t * font)
 {
-    if(font == NULL) {
-        return;
-    }
+    LV_ASSERT_NULL(font);
 
     imgfont_dsc_t * dsc = (imgfont_dsc_t *)font->dsc;
     lv_free(dsc);
@@ -104,7 +102,9 @@ static bool imgfont_get_glyph_dsc(const lv_font_t * font, lv_font_glyph_dsc_t *
     LV_ASSERT_NULL(dsc);
     if(dsc->path_cb == NULL) return false;
 
-    if(!dsc->path_cb(dsc->font, dsc->path, LV_IMGFONT_PATH_MAX_LEN, unicode, unicode_next, dsc->user_data)) {
+    lv_coord_t offset_y = 0;
+
+    if(!dsc->path_cb(dsc->font, dsc->path, LV_IMGFONT_PATH_MAX_LEN, unicode, unicode_next, &offset_y, dsc->user_data)) {
         return false;
     }
 
@@ -134,7 +134,7 @@ static bool imgfont_get_glyph_dsc(const lv_font_t * font, lv_font_glyph_dsc_t *
     dsc_out->box_h = img_header->h;
     dsc_out->bpp = LV_IMGFONT_BPP;   /* is image identifier */
     dsc_out->ofs_x = 0;
-    dsc_out->ofs_y = 0;
+    dsc_out->ofs_y = offset_y;
 
     return true;
 }

src/others/imgfont/lv_imgfont.h

@@ -26,9 +26,9 @@ extern "C" {
  **********************/
 
 /* gets the image path name of this character */
-typedef bool (*lv_get_imgfont_path_cb_t)(const lv_font_t * font, void * img_src,
+typedef bool (*lv_imgfont_get_path_cb_t)(const lv_font_t * font, void * img_src,
                                          uint16_t len, uint32_t unicode, uint32_t unicode_next,
-                                         void * user_data);
+                                         lv_coord_t * offset_y, void * user_data);
 
 /**********************
  * GLOBAL PROTOTYPES
@@ -40,7 +40,7 @@ typedef bool (*lv_get_imgfont_path_cb_t)(const lv_font_t * font, void * img_src,
  * @param path_cb a function to get the image path name of character.
  * @return pointer to the new imgfont or NULL if create error.
  */
-lv_font_t * lv_imgfont_create(uint16_t height, lv_get_imgfont_path_cb_t path_cb, void * user_data);
+lv_font_t * lv_imgfont_create(uint16_t height, lv_imgfont_get_path_cb_t path_cb, void * user_data);
 
 /**
  * Destroy a image font that has been created.