From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sat, 26 Aug 2023 01:43:57 +0000 (-0700)
Subject: Use float not double in webp_load alpha conversion
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=8bc21ef1109bb0a82485920ac067bbc06d377f86;p=emacs.git

Use float not double in webp_load alpha conversion

* src/image.c (webp_load): Pacify gcc -Wdouble-promotion
by using (1 - a), where the 1 is converted to 1.0f, rather
than (1.0 - a), which mistakenly converts a to double.
Also, reindent to use GNU style.
---

diff --git a/src/image.c b/src/image.c
index 70dd280b5dd..e785659aea1 100644
--- a/src/image.c
+++ b/src/image.c
@@ -10497,17 +10497,20 @@ webp_load (struct frame *f, struct image *img)
 	  int r, g, b;
 	  /* The WebP alpha channel allows 256 levels of partial
 	     transparency.  Blend it with the background manually.  */
-	  if (features.has_alpha || anim) {
-	    float a = (float) p[3] / UINT8_MAX;
-	    r = (int)(a * p[0] + (1.0 - a) * bg_color.red)   << 8;
-	    g = (int)(a * p[1] + (1.0 - a) * bg_color.green) << 8;
-	    b = (int)(a * p[2] + (1.0 - a) * bg_color.blue)  << 8;
-	    p += 4;
-	  } else {
-	    r = *p++ << 8;
-	    g = *p++ << 8;
-	    b = *p++ << 8;
-	  }
+	  if (features.has_alpha || anim)
+	    {
+	      float a = (float) p[3] / UINT8_MAX;
+	      r = (int)(a * p[0] + (1 - a) * bg_color.red)   << 8;
+	      g = (int)(a * p[1] + (1 - a) * bg_color.green) << 8;
+	      b = (int)(a * p[2] + (1 - a) * bg_color.blue)  << 8;
+	      p += 4;
+	    }
+	  else
+	    {
+	      r = *p++ << 8;
+	      g = *p++ << 8;
+	      b = *p++ << 8;
+	    }
 	  PUT_PIXEL (ximg, x, y, lookup_rgb_color (f, r, g, b));
 	}
     }