allow image mods for overlay image mod

doc/PACKS.md

@@ -231,7 +231,8 @@ a table representing an enum with the following constants: \
 
   + img_mods filter to be applied on the img
     - `@disabled`: grey-scale
-    - `overlay|path/to/img.png`: draw a second image over it
+    - `overlay|path/to/img.png|overlay_filters...`: draw a second image over it; overlay_filters are applied to overlay (since 0.25.6)
+    - NOTE: order matters, applied left to right
   + inherit_codes: true will make stage3 provide codes for item, stage1, 2 and 3 (default true)
 
 * `"toggle"`:

src/ui/trackerview.cpp

@@ -15,6 +15,8 @@
 #include "maptooltip.h"
 #include "mapwidget.h"
 #include "defaults.h" // DEFAULT_FONT_*
+#include <string>
+#include <vector>
 
 namespace Ui {
 
@@ -25,23 +27,35 @@ std::list<ImageFilter> imageModsToFilters(Tracker* tracker, const std::list<std:
 {
     std::list<ImageFilter> filters;
     for (auto& mod: mods) {
-        std::string name, arg;
+        std::string name;
+        std::vector<std::string> args;
         size_t p = mod.find('|');
         if (p == mod.npos) name = mod;
         else {
             name = mod.substr(0,p);
-            arg  = mod.substr(p+1);
+            while (true) {
+                auto q = mod.find('|', p+1);
+                if (q == mod.npos) {
+                    args.push_back(mod.substr(p+1));
+                    break;
+                }
+                args.push_back(mod.substr(p+1, q-p-1));
+                p = q;
+            }
         }
         if (name == "overlay") {
             // read actual image data into arg instead of filename
-            std::string tmp = std::move(arg);
-            tracker->getPack()->ReadFile(tmp, arg);
+            std::string tmp = std::move(args[0]);
+            tracker->getPack()->ReadFile(tmp, args[0]);
+            for (size_t i=1; i<args.size(); i++)
+                if (args[i] == "@disable" || args[i] == "@disabled")
+                    args[i] = "grey";
         }
         if (name == "@disable" || name == "@disabled")
         {
             name = "grey";
         }
-        filters.push_back({name,arg});
+        filters.push_back({name,args});
     }
     return filters;
 }

src/uilib/imagefilter.cpp

@@ -4,23 +4,31 @@
 
 namespace Ui {
 
-SDL_Surface* ImageFilter::apply(SDL_Surface *surf)
+SDL_Surface* ImageFilter::apply(SDL_Surface *surf) const
 {
     if (!surf) return surf;
 
     if (name=="grey" || name=="disable") {
         return makeGreyscale(surf, true);
     }
-    if (name=="overlay" && !arg.empty()) {
-        auto overlay = IMG_Load_RW(SDL_RWFromMem((void*)arg.c_str(), (int)arg.length()), 1);
+    if (name=="overlay" && !args.empty()) {
+        auto overlay = IMG_Load_RW(SDL_RWFromMem((void*)args[0].c_str(), (int)args[0].length()), 1);
         overlay = makeTransparent(overlay, 0xff, 0x00, 0xff, false);
         if (overlay) {
+            bool first = true;
+            for (const auto& arg: args) {
+                if (first) {
+                    first = false; // skip the first arg (the image)
+                } else {
+                    overlay = ImageFilter(arg).apply(overlay);
+                }
+            }
             SDL_BlitSurface(overlay, nullptr, surf, nullptr);
             SDL_FreeSurface(overlay);
         }
         else {
             fprintf(stderr, "IMG_Load: %s\n", IMG_GetError());
-        }        
+        }
     }
 
     return surf;

src/uilib/imagefilter.h

@@ -4,23 +4,36 @@
 
 #include "colorhelper.h"
 #include <string>
+#include <vector>
 #include <SDL2/SDL_image.h>
 
 
 namespace Ui {
 
 struct ImageFilter {
-    ImageFilter(std::string name) { this->name=name; }
-    ImageFilter(std::string name, std::string arg) { this->name=name; this->arg=arg; }
-
+    ImageFilter(std::string name)
+        : name(name)
+    {
+    }
+
+    ImageFilter(std::string name, std::string arg)
+        : name(name), args({arg})
+    {
+    }
+
+    ImageFilter(std::string name, std::vector<std::string>& args)
+        : name(name), args(args)
+    {
+    }
+
     std::string name;
-    std::string arg;
+    std::vector<std::string> args;
 
-    SDL_Surface* apply(SDL_Surface *surf);
+    SDL_Surface* apply(SDL_Surface *surf) const;
 
     bool operator==(const ImageFilter& rhs) const
     {
-        return name == rhs.name && arg == rhs.arg;
+        return name == rhs.name && args == rhs.args;
     }
 };