From fa85ec5cf533fb3e597df44c05887f61f70c1857 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Timm=20B=C3=A4der?= <mail@baedert.org>
Date: Fri, 24 Jul 2020 18:33:33 +0200
Subject: [PATCH] GskTransform: Restructure _to_affine and _to_translation

Make the simple cases more explicit.
---
 gsk/gsktransform.c | 72 ++++++++++++++++++++++++++++++++--------------
 1 file changed, 50 insertions(+), 22 deletions(-)

diff --git a/gsk/gsktransform.c b/gsk/gsktransform.c
index eabdd7861f..a12c68e557 100644
--- a/gsk/gsktransform.c
+++ b/gsk/gsktransform.c
@@ -1539,7 +1539,7 @@ gsk_transform_to_2d (GskTransform *self,
  * Converts a #GskTransform to 2D affine transformation
  * factors.
  * @self must be a 2D transformation. If you are not
- * sure, use gsk_transform_get_category() >= 
+ * sure, use gsk_transform_get_category() >=
  * %GSK_TRANSFORM_CATEGORY_2D_AFFINE to check.
  */
 void
@@ -1549,15 +1549,8 @@ gsk_transform_to_affine (GskTransform *self,
                          float        *out_dx,
                          float        *out_dy)
 {
-  if (self == NULL ||
-      self->category < GSK_TRANSFORM_CATEGORY_2D_AFFINE)
+  if (self == NULL)
     {
-      if (self != NULL)
-        {
-          char *s = gsk_transform_to_string (self);
-          g_warning ("Given transform \"%s\" is not an affine 2D transform.", s);
-          g_free (s);
-        }
       *out_scale_x = 1.0f;
       *out_scale_y = 1.0f;
       *out_dx = 0.0f;
@@ -1565,9 +1558,32 @@ gsk_transform_to_affine (GskTransform *self,
       return;
     }
 
-  gsk_transform_to_affine (self->next,
-                           out_scale_x, out_scale_y,
-                           out_dx, out_dy);
+  if (G_UNLIKELY (self->category < GSK_TRANSFORM_CATEGORY_2D_AFFINE))
+    {
+      char *s = gsk_transform_to_string (self);
+      g_warning ("Given transform \"%s\" is not an affine 2D transform.", s);
+      g_free (s);
+
+      *out_scale_x = 1.0f;
+      *out_scale_y = 1.0f;
+      *out_dx = 0.0f;
+      *out_dy = 0.0f;
+      return;
+    }
+
+  if (self->next != NULL)
+    {
+      gsk_transform_to_affine (self->next,
+                               out_scale_x, out_scale_y,
+                               out_dx, out_dy);
+    }
+  else
+    {
+      *out_scale_x = 1.0f;
+      *out_scale_y = 1.0f;
+      *out_dx = 0.0f;
+      *out_dy = 0.0f;
+    }
 
   self->transform_class->apply_affine (self,
                                        out_scale_x, out_scale_y,
@@ -1592,22 +1608,34 @@ gsk_transform_to_translate (GskTransform *self,
                             float        *out_dx,
                             float        *out_dy)
 {
-  if (self == NULL ||
-      self->category < GSK_TRANSFORM_CATEGORY_2D_TRANSLATE)
+  if (self == NULL)
     {
-      if (self != NULL)
-        {
-          char *s = gsk_transform_to_string (self);
-          g_warning ("Given transform \"%s\" is not a 2D translation.", s);
-          g_free (s);
-        }
       *out_dx = 0.0f;
       *out_dy = 0.0f;
       return;
     }
 
-  gsk_transform_to_translate (self->next,
-                              out_dx, out_dy);
+  if (G_UNLIKELY (self->category < GSK_TRANSFORM_CATEGORY_2D_TRANSLATE))
+    {
+      char *s = gsk_transform_to_string (self);
+      g_warning ("Given transform \"%s\" is not an affine 2D translation.", s);
+      g_free (s);
+
+      *out_dx = 0.0f;
+      *out_dy = 0.0f;
+      return;
+    }
+
+  if (self->next != NULL)
+    {
+      gsk_transform_to_translate (self->next,
+                                  out_dx, out_dy);
+    }
+  else
+    {
+      *out_dx = 0.0f;
+      *out_dy = 0.0f;
+    }
 
   self->transform_class->apply_translate (self,
                                           out_dx, out_dy);
-- 
2.30.2