From 832617188f78ae61f595f275a09b07a2bcb48890 Mon Sep 17 00:00:00 2001
From: Thomas Bernard <miniupnp@free.fr>
Date: Tue, 20 Nov 2018 10:53:16 +0100
Subject: [PATCH] improve Update_pixel_renderer()

+doxygen
---
 src/graph.c  | 79 ++++++++++++++++++++++++++++------------------------
 src/struct.h |  2 +-
 2 files changed, 43 insertions(+), 38 deletions(-)

diff --git a/src/graph.c b/src/graph.c
index 6d7c62dd..d2fd69bc 100644
--- a/src/graph.c
+++ b/src/graph.c
@@ -3603,58 +3603,63 @@ byte Read_pixel_from_current_layer(word x,word y)
   return *((y)*Main.image_width+(x)+Main.backups->Pages->Image[Main.current_layer].Pixels);
 }
 
+/**
+ * Update the pixel functions according to the current Image_mode.
+ *
+ * Pixel_in_current_screen and Pixel_in_current_screen_with_preview are updated.
+ */
 void Update_pixel_renderer(void)
 {
-  if (Main.backups->Pages->Image_mode == IMAGE_MODE_ANIMATION)
+  switch (Main.backups->Pages->Image_mode)
   {
+  case IMAGE_MODE_C64MULTI: //TODO
+  case IMAGE_MODE_C64FLI: //TODO
+  case IMAGE_MODE_GBC:  // TODO
+  case IMAGE_MODE_ANIMATION:
     // direct
     Pixel_in_current_screen = Pixel_in_screen_direct;
     Pixel_in_current_screen_with_preview = Pixel_in_screen_direct_with_preview;
-  }
-  else
-  if (Main.backups->Pages->Image_mode == IMAGE_MODE_LAYERED)
-  {
+    break;
+  case IMAGE_MODE_LAYERED:
     // layered
     Pixel_in_current_screen = Pixel_in_screen_layered;
     Pixel_in_current_screen_with_preview = Pixel_in_screen_layered_with_preview;
-  }
-  else
-  if (Main.backups->Pages->Image_mode == IMAGE_MODE_EGX
-   || Main.backups->Pages->Image_mode == IMAGE_MODE_EGX2)
-  {
+    break;
+  case IMAGE_MODE_EGX:
+  case IMAGE_MODE_EGX2:
     // special "EGX" mode
     Pixel_in_current_screen = Pixel_in_screen_egx;
     Pixel_in_current_screen_with_preview = Pixel_in_screen_egx_with_preview;
-  }
-  else
-  if (Main.backups->Pages->Image_mode == IMAGE_MODE_THOMSON)
-  {
+    break;
+  case IMAGE_MODE_THOMSON:
     Pixel_in_current_screen = Pixel_in_screen_thomson;
     Pixel_in_current_screen_with_preview = Pixel_in_screen_thomson_with_preview;
-  }
-  else
-  if (Main.backups->Pages->Image_mode == IMAGE_MODE_ZX)
-  {
+    break;
+  case IMAGE_MODE_C64HIRES:
+  case IMAGE_MODE_ZX:
     Pixel_in_current_screen = Pixel_in_screen_zx;
     Pixel_in_current_screen_with_preview = Pixel_in_screen_zx_with_preview;
-  }
-  // Implicit else : Image_mode must be IMAGE_MODE_MODE5 or IMAGE_MODE_RASTER
-  else if ( Main.current_layer == 4)
-  {
-    // overlay
-    Pixel_in_current_screen = Pixel_in_screen_overlay;
-    Pixel_in_current_screen_with_preview = Pixel_in_screen_overlay_with_preview;
-  }
-  else if (Main.current_layer<4 && (Main.layers_visible & (1<<4)))
-  {
-    // underlay
-    Pixel_in_current_screen = Pixel_in_screen_underlay;
-    Pixel_in_current_screen_with_preview = Pixel_in_screen_underlay_with_preview;
-  }
-  else
-  {
-    // layered (again, for layers > 4 in MODE5 and RASTER)
-    Pixel_in_current_screen = Pixel_in_screen_layered;
-    Pixel_in_current_screen_with_preview = Pixel_in_screen_layered_with_preview;
+    break;
+  case IMAGE_MODE_MODE5:
+  case IMAGE_MODE_RASTER:
+    if ( Main.current_layer == 4)
+    {
+      // overlay
+      Pixel_in_current_screen = Pixel_in_screen_overlay;
+      Pixel_in_current_screen_with_preview = Pixel_in_screen_overlay_with_preview;
+    }
+    else if (Main.current_layer<4 && (Main.layers_visible & (1<<4)))
+    {
+      // underlay
+      Pixel_in_current_screen = Pixel_in_screen_underlay;
+      Pixel_in_current_screen_with_preview = Pixel_in_screen_underlay_with_preview;
+    }
+    else
+    {
+      // layered (again, for layers > 4 in MODE5 and RASTER)
+      Pixel_in_current_screen = Pixel_in_screen_layered;
+      Pixel_in_current_screen_with_preview = Pixel_in_screen_layered_with_preview;
+    }
+    break;
   }
 }
diff --git a/src/struct.h b/src/struct.h
index 6efc2e88..27253f3e 100644
--- a/src/struct.h
+++ b/src/struct.h
@@ -406,7 +406,7 @@ typedef struct T_Page
   int       Height;  ///< Image height in pixels.
   T_Palette Palette; ///< Image palette.
 
-  byte      Image_mode; ///< 0= layered image, 1=animation,
+  enum IMAGE_MODES Image_mode; ///< 0= layered image, 1=animation,
 
   char      Comment[COMMENT_SIZE+1]; ///< Comment to store in the image file.