From b8356ebe6cfcb5e1b0818101b5174b83cd220e9b Mon Sep 17 00:00:00 2001
From: Gabor Kiss-Vamosi <kisvegabor@gmail.com>
Date: Fri, 1 Sep 2023 11:13:21 +0200
Subject: [PATCH] fix(draw): stride handling for RGB565A8 images

---
 src/draw/lv_img_decoder.c       | 20 ++++++++++++++------
 src/draw/sw/lv_draw_sw_letter.c |  4 +++-
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/src/draw/lv_img_decoder.c b/src/draw/lv_img_decoder.c
index a7c294ba5..fc69d3cc5 100644
--- a/src/draw/lv_img_decoder.c
+++ b/src/draw/lv_img_decoder.c
@@ -34,6 +34,7 @@ typedef struct {
 static lv_res_t decode_indexed_line(lv_color_format_t color_format, const lv_color32_t * palette, lv_coord_t y,
                                     lv_coord_t w_px, const uint8_t * in, lv_color32_t * out);
 
+static uint32_t img_width_to_stride(lv_img_header_t * header);
 /**********************
  *  STATIC VARIABLES
  **********************/
@@ -93,9 +94,7 @@ lv_res_t lv_img_decoder_get_info(const void * src, lv_img_header_t * header)
         if(d->info_cb) {
             res = d->info_cb(d, src, header);
             if(res == LV_RES_OK) {
-                if(header->stride == 0) {
-                    header->stride = header->w * lv_color_format_get_size(header->cf);
-                }
+                if(header->stride == 0) header->stride = img_width_to_stride(header);
                 break;
             }
         }
@@ -143,9 +142,7 @@ lv_res_t lv_img_decoder_open(lv_img_decoder_dsc_t * dsc, const void * src, lv_co
         res = decoder->info_cb(decoder, src, &dsc->header);
         if(res != LV_RES_OK) continue;
 
-        if(dsc->header.stride == 0) {
-            dsc->header.stride = dsc->header.w * lv_color_format_get_size(dsc->header.cf);
-        }
+        if(dsc->header.stride == 0) dsc->header.stride = img_width_to_stride(&dsc->header);
 
         dsc->decoder = decoder;
         res = decoder->open_cb(decoder, dsc);
@@ -483,3 +480,14 @@ static lv_res_t decode_indexed_line(lv_color_format_t color_format, const lv_col
     }
     return LV_RES_OK;
 }
+
+
+static uint32_t img_width_to_stride(lv_img_header_t * header)
+{
+    if(header->cf == LV_COLOR_FORMAT_RGB565A8) {
+        return header->w * 2;
+    }
+    else {
+        return header->w * lv_color_format_get_size(header->cf);
+    }
+}
diff --git a/src/draw/sw/lv_draw_sw_letter.c b/src/draw/sw/lv_draw_sw_letter.c
index c987e26a4..5f4a19f46 100644
--- a/src/draw/sw/lv_draw_sw_letter.c
+++ b/src/draw/sw/lv_draw_sw_letter.c
@@ -76,12 +76,14 @@ LV_ATTRIBUTE_FAST_MEM static void draw_letter_cb(lv_draw_unit_t * draw_unit, lv_
 #endif
         }
         else if(glyph_draw_dsc->format == LV_DRAW_LETTER_BITMAP_FORMAT_A8) {
+            lv_area_t mask_area = *glyph_draw_dsc->letter_coords;
+            mask_area.x2 = mask_area.x1 + lv_draw_buf_width_to_stride(lv_area_get_width(&mask_area), LV_COLOR_FORMAT_A8) - 1;
             lv_draw_sw_blend_dsc_t blend_dsc;
             lv_memzero(&blend_dsc, sizeof(blend_dsc));
             blend_dsc.color = glyph_draw_dsc->color;
             blend_dsc.opa = glyph_draw_dsc->opa;
             blend_dsc.mask_buf = glyph_draw_dsc->bitmap;
-            blend_dsc.mask_area = glyph_draw_dsc->letter_coords;
+            blend_dsc.mask_area = &mask_area;
             blend_dsc.blend_area = glyph_draw_dsc->letter_coords;
             blend_dsc.mask_res = LV_DRAW_SW_MASK_RES_CHANGED;