Fix font shadow color

Use the average alpha value for rendering text. Resolves #150. Signed-off-by: Artem Senichev <[email protected]>
artemsen · Jul 10, 2024 · c2ed948 · c2ed948
1 parent 2f33c4c
commit c2ed948
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Showing 4 changed files with 18 additions and 17 deletions.
diff --git a/extra/swayimgrc b/extra/swayimgrc
@@ -68,10 +68,10 @@ preload = 1
 name = monospace
 # Font size (in pt)
 size = 14
-# Font color
+# Font color (RGB or RGBA, e.g. #11223344)
 color = #cccccc
-# Drop shadow (none/RGB, e.g. #112233)
-shadow = #000000
+# Shadow color (RGB or RGBA, disable: #00000000)
+shadow = #000000a0
 
 ################################################################################
 # Image meta info scheme (format, size, EXIF, etc)

diff --git a/extra/swayimgrc.5 b/extra/swayimgrc.5
@@ -135,8 +135,9 @@ Set the font size (in pt), default is \fI14\fR.
 .IP "\fBcolor\fR = \fI#COLOR\fR"
 Set text color in RGB hex format, default is \fI#cccccc\fR.
 .\" ----------------------------------------------------------------------------
-.IP "\fBshadow\fR = \fI[none|COLOR]\fR"
-Draw text shadow with specified color, default is \fI#000000\fR.
+.IP "\fBshadow\fR = \fI#COLOR\fR"
+Draw text shadow with specified color, default is \fI#000000a0\fR.
+To disable shadow use fully transparent color \fI#00000000\fR.
 .\" ****************************************************************************
 .\" Text info config section
 .\" ****************************************************************************

diff --git a/src/pixmap.c b/src/pixmap.c
@@ -147,9 +147,12 @@ void pixmap_apply_mask(struct pixmap* dst, size_t x, size_t y,
         const uint8_t* mask_line = &mask[mask_y * width];
 
         for (size_t mask_x = 0; mask_x < mask_width; ++mask_x) {
-            const uint8_t alpha = mask_line[mask_x];
-            if (alpha != 0) {
-                alpha_blend(ARGB_SET_A(alpha) | color, &dst_line[mask_x]);
+            const uint8_t alpha_mask = mask_line[mask_x];
+            if (alpha_mask != 0) {
+                const uint8_t alpha_color = ARGB_GET_A(color);
+                const uint8_t alpha = ((uint32_t)alpha_mask + alpha_color) / 2;
+                const argb_t clr = ARGB_SET_A(alpha) | (color & 0x00ffffff);
+                alpha_blend(clr, &dst_line[mask_x]);
             }
         }
     }

diff --git a/src/text.c b/src/text.c
@@ -9,11 +9,8 @@
 
 #include <string.h>
 
-// Text rendering parameters
-#define TEXT_COLOR     0x00cccccc
-#define TEXT_SHADOW    0x00000000
-#define TEXT_NO_SHADOW 0xff000000
-#define TEXT_PADDING   10 // space between text layout and window edge
+// Space between text layout and window edge
+#define TEXT_PADDING 10
 
 /** Text context. */
 struct text {
@@ -22,8 +19,8 @@ struct text {
 };
 
 static struct text ctx = {
-    .color = TEXT_COLOR,
-    .shadow = TEXT_SHADOW,
+    .color = 0xffcccccc,
+    .shadow = 0x80000000,
 };
 
 /**
@@ -35,7 +32,7 @@ static struct text ctx = {
 static void draw_text(struct pixmap* wnd, size_t x, size_t y,
                       const struct text_surface* text)
 {
-    if (ctx.shadow != TEXT_NO_SHADOW) {
+    if (ARGB_GET_A(ctx.shadow)) {
         size_t shadow_offset = text->height / 16;
         if (shadow_offset < 1) {
             shadow_offset = 1;
@@ -61,7 +58,7 @@ static enum config_status load_config(const char* key, const char* value)
         }
     } else if (strcmp(key, "shadow") == 0) {
         if (strcmp(value, "none") == 0) {
-            ctx.shadow = TEXT_NO_SHADOW;
+            ctx.shadow = 0;
             status = cfgst_ok;
         } else if (config_to_color(value, &ctx.shadow)) {
             status = cfgst_ok;