From: Benjamin Otte <otte@redhat.com>
Date: Fri, 21 Jul 2023 23:11:19 +0000 (+0200)
Subject: gdk: Add function to query alpha format for depth
X-Git-Tag: archive/raspbian/4.12.3+ds-1+rpi1~1^2^2^2~22^2~1^2~52^2
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=b1b8a9856895ea5b06c9ac3019d7c6cebfe5470f;p=gtk4.git

gdk: Add function to query alpha format for depth

It's meant to be used in renderers.
---

diff --git a/gdk/gdkmemoryformat.c b/gdk/gdkmemoryformat.c
index 95663e9ba7..ec5583a2ad 100644
--- a/gdk/gdkmemoryformat.c
+++ b/gdk/gdkmemoryformat.c
@@ -704,6 +704,33 @@ gdk_memory_depth_merge (GdkMemoryDepth depth1,
     }
 }
 
+/*
+ * gdk_memory_depth_get_alpha_format:
+ * @depth: the depth
+ *
+ * Gets the preferred format to use for rendering masks and other
+ * alpha-only content.
+ *
+ * Returns: the format
+ **/
+GdkMemoryFormat
+gdk_memory_depth_get_alpha_format (GdkMemoryDepth depth)
+{
+  switch (depth)
+    {
+      case GDK_MEMORY_U8:
+        return GDK_MEMORY_A8;
+      case GDK_MEMORY_U16:
+        return GDK_MEMORY_A16;
+      case GDK_MEMORY_FLOAT16:
+        return GDK_MEMORY_A16_FLOAT;
+      case GDK_MEMORY_FLOAT32:
+        return GDK_MEMORY_A32_FLOAT;
+      default:
+        g_return_val_if_reached (GDK_MEMORY_A8);
+    }
+}
+
 gboolean
 gdk_memory_format_gl_format (GdkMemoryFormat  format,
                              gboolean         gles,
diff --git a/gdk/gdkmemoryformatprivate.h b/gdk/gdkmemoryformatprivate.h
index 07286d9a6c..9f56442de5 100644
--- a/gdk/gdkmemoryformatprivate.h
+++ b/gdk/gdkmemoryformatprivate.h
@@ -44,6 +44,7 @@ gsize                   gdk_memory_format_bytes_per_pixel   (GdkMemoryFormat
 GdkMemoryDepth          gdk_memory_format_get_depth         (GdkMemoryFormat             format) G_GNUC_CONST;
 GdkMemoryDepth          gdk_memory_depth_merge              (GdkMemoryDepth              depth1,
                                                              GdkMemoryDepth              depth2) G_GNUC_CONST;
+GdkMemoryFormat         gdk_memory_depth_get_alpha_format   (GdkMemoryDepth              depth) G_GNUC_CONST;
 gboolean                gdk_memory_format_gl_format         (GdkMemoryFormat             format,
                                                              gboolean                    gles,
                                                              guint                       gl_major,