Added new public API routine R_GetPatchName for querying the name

associated with a unique patch identifier.

I opted not to make use of patchinfo_t because the games currently
statically-allocate copies of this struct.

This needs cleaning up; either:
a) engine manages the extended info and stores it so the game can
retrieve an immutable pointer to it whenever it is required
b) game asks the engine to dynamically allocate the info which the
game should then take care to destroy when no longer needed.

doomsday/engine/api/doomsday.def

@@ -1,7 +1,7 @@
 ; Doomsday Engine API (Routines exported from Doomsday.exe).
 ;
 ; Highest ordinal is currently: --> 510 <--
-; Other free ordinals: 90 133 247
+; Other free ordinals: 90 133
 
 NAME                            "DOOMSDAY"
 EXPORTS
@@ -375,6 +375,7 @@ EXPORTS
     R_SetBorderGfx              @93 NONAME
     R_GetSpriteInfo             @94 NONAME
     R_GetPatchInfo              @237 NONAME
+    R_GetPatchName              @247 NONAME
     R_PointToAngle2             @101 NONAME
     R_PointInSubsector          @102 NONAME
     R_HSVToRGB                  @439 NONAME

doomsday/engine/api/doomsday.h

@@ -467,7 +467,8 @@ scalemode_t R_ChooseScaleMode(int width, int height, int availWidth, int availHe
 
     void            R_SetBorderGfx(const dduri_t* paths[9]);
     boolean         R_GetSpriteInfo(int sprite, int frame, spriteinfo_t* sprinfo);
-    boolean         R_GetPatchInfo(patchid_t id, patchinfo_t* info);
+boolean R_GetPatchInfo(patchid_t id, patchinfo_t* info);
+const ddstring_t* R_GetPatchName(patchid_t id);
     void            R_HSVToRGB(float* rgb, float h, float s, float v);
     angle_t         R_PointToAngle2(float x1, float y1, float x2, float y2);
     struct subsector_s* R_PointInSubsector(float x, float y);

doomsday/engine/portable/include/r_data.h

@@ -482,7 +482,17 @@ patchid_t       R_RegisterPatch(const char* name);
 
 patchtex_t*     R_PatchTextureByIndex(patchid_t id);
 void            R_ClearPatchTexs(void);
-boolean         R_GetPatchInfo(patchid_t id, patchinfo_t* info);
+
+/**
+ * Retrieve extended info for the patch associated with @a id.
+ * @param id  Unique identifier of the patch to lookup.
+ * @param info  Extend info will be written here if found.
+ * @return  @c true= Extended info for this patch was found.
+ */
+boolean R_GetPatchInfo(patchid_t id, patchinfo_t* info);
+
+/// @return  Name of the patch associated with @a id.
+const ddstring_t* R_GetPatchName(patchid_t id);
 
 void R_InitRawTexs(void);
 void R_UpdateRawTexs(void);

doomsday/engine/portable/src/r_data.c

@@ -1145,28 +1145,45 @@ patchid_t R_RegisterPatch(const char* name)
 
 boolean R_GetPatchInfo(patchid_t id, patchinfo_t* info)
 {
+    const patchtex_t* patch;
     if(!info)
         Con_Error("R_GetPatchInfo: Argument 'info' cannot be NULL.");
-    {
-    const patchtex_t* p;
+
     memset(info, 0, sizeof(*info));
-    if(NULL != (p = getPatchTex(id)))
+    patch = getPatchTex(id);
+    if(NULL != patch)
     {
-        texture_t* tex = GL_ToTexture(p->texId);
+        texture_t* tex = GL_ToTexture(patch->texId);
         assert(NULL != tex);
         info->id = id;
         info->width = Texture_Width(tex);
         info->height = Texture_Height(tex);
-        info->offset = p->offX;
-        info->topOffset = p->offY;
-        info->isCustom = p->isCustom;
+        info->offset = patch->offX;
+        info->topOffset = patch->offY;
+        info->isCustom = patch->isCustom;
         /// \kludge:
-        info->extraOffset[0] = info->extraOffset[1] = (p->flags & PF_UPSCALE_AND_SHARPEN)? -1 : 0;
+        info->extraOffset[0] = info->extraOffset[1] = (patch->flags & PF_UPSCALE_AND_SHARPEN)? -1 : 0;
         return true;
     }
-    VERBOSE(Con_Message("R_GetPatchInfo: Warning, unknown Patch %i.\n", id));
+    if(id != 0)
+    {
+        VERBOSE( Con_Message("Warning:R_GetPatchInfo Invalid Patch id #%u.\n", (uint)id) )
+    }
     return false;
+}
+
+const ddstring_t* R_GetPatchName(patchid_t id)
+{
+    const patchtex_t* patch = getPatchTex(id);
+    if(NULL != patch)
+    {
+        return &patch->name;
     }
+    if(id != 0)
+    {
+        VERBOSE( Con_Message("Warning:R_GetPatchName: Invalid Patch id #%u.\n", (uint)id) )
+    }
+    return NULL;
 }
 
 patchid_t R_PrecachePatch(const char* name, patchinfo_t* info)