New: function imImageSetAlpha.

3 files changed, 46 insertions, 2 deletions

diff --git a/src/im.def b/src/im.def
index 6efacc4..9c448d5 100644
--- a/src/im.def
+++ b/src/im.def
@@ -121,6 +121,7 @@ EXPORTS
   imImageCopyPlane
   imImageCreateBased
   imImageAddAlpha
+  imImageSetAlpha
   imDibToHBitmap
   imDibLogicalPalette
   imDibCaptureScreen
diff --git a/src/im_image.cpp b/src/im_image.cpp
index 171d897..5f865f8 100644
--- a/src/im_image.cpp
+++ b/src/im_image.cpp
@@ -2,7 +2,7 @@
  * \brief Image Manipulation
  *
  * See Copyright Notice in im_lib.h
- * $Id: im_image.cpp,v 1.6 2010/01/15 17:21:47 scuri Exp $
+ * $Id: im_image.cpp,v 1.7 2010/01/17 18:18:12 scuri Exp $
  */
 
 #include <stdlib.h>
@@ -273,6 +273,39 @@ void imImageClear(imImage* image)
     memset(image->data[image->depth], 0, image->plane_size);
 }
 
+template <class T> 
+inline void iSet(T *map, T value, int count)
+{
+  for (int i = 0; i < count; i++)
+  {
+    *map++ = value;
+  }
+}
+  
+void imImageSetAlpha(imImage* image, float alpha)
+{
+  assert(image);
+
+  if (image->has_alpha)
+  {
+    switch(image->data_type)
+    {
+    case IM_BYTE:
+      memset(image->data[image->depth], (imbyte)alpha, image->plane_size);
+      break;                                                                                
+    case IM_USHORT:                                                                           
+      iSet((imushort*)image->data[image->depth], (imushort)alpha, image->plane_size);
+      break;                                                                                
+    case IM_INT:                                                                           
+      iSet((int*)image->data[image->depth], (int)alpha, image->plane_size);
+      break;                                                                                
+    case IM_FLOAT:                                                                           
+      iSet((float*)image->data[image->depth], (float)alpha, image->plane_size);
+      break;                                                                                
+    }
+  }
+}
+
 int imImageIsBitmap(const imImage* image)
 {
   assert(image);
diff --git a/src/lua5/imlua_image.c b/src/lua5/imlua_image.c
index 77cc499..9900e7d 100644
--- a/src/lua5/imlua_image.c
+++ b/src/lua5/imlua_image.c
@@ -2,7 +2,7 @@
  * \brief IM Lua 5 Binding
  *
  * See Copyright Notice in im_lib.h
- * $Id: imlua_image.c,v 1.8 2010/01/15 17:23:13 scuri Exp $
+ * $Id: imlua_image.c,v 1.9 2010/01/17 18:18:12 scuri Exp $
  */
 
 #include <string.h>
@@ -128,6 +128,15 @@ static int imluaImageAddAlpha (lua_State *L)
 }
 
 /*****************************************************************************\
+ image:SetAlpha()
+\*****************************************************************************/
+static int imluaImageSetAlpha (lua_State *L)
+{
+  imImageSetAlpha(imlua_checkimage(L, 1), (float)luaL_checknumber(L, 2));
+  return 0;
+}
+
+/*****************************************************************************\
  image:Reshape()
 \*****************************************************************************/
 static int imluaImageReshape (lua_State *L)
@@ -1016,6 +1025,7 @@ static const luaL_reg imimage_lib[] = {
 static const luaL_reg imimage_metalib[] = {
   {"Destroy", imluaImageDestroy},
   {"AddAlpha", imluaImageAddAlpha},
+  {"SetAlpha", imluaImageSetAlpha},
   {"Reshape", imluaImageReshape},
   {"Copy", imluaImageCopy},
   {"CopyData", imluaImageCopyData},