Implement a PenArray class for caching parts of rendered screens

library/LuaApi.cpp

@@ -1041,6 +1041,88 @@ static void OpenPen(lua_State *state)
     lua_pop(state, 1);
 }
 
+/******************
+* PenArray object *
+******************/
+
+static int DFHACK_PENARRAY_TOKEN = 0;
+using Screen::PenArray;
+
+static PenArray *check_penarray_native(lua_State *L, int index)
+{
+    lua_rawgetp(L, LUA_REGISTRYINDEX, &DFHACK_PENARRAY_TOKEN);
+
+    if (!lua_getmetatable(L, index) || !lua_rawequal(L, -1, -2))
+        luaL_argerror(L, index, "not a penarray object");
+
+    lua_pop(L, 2);
+
+    return (PenArray*)lua_touserdata(L, index);
+}
+
+static int dfhack_penarray_new(lua_State *L)
+{
+    int bufwidth = luaL_checkint(L, 1);
+    int bufheight = luaL_checkint(L, 2);
+    new (L) PenArray(bufwidth, bufheight);
+
+    lua_rawgetp(L, LUA_REGISTRYINDEX, &DFHACK_PENARRAY_TOKEN);
+    lua_setmetatable(L, -2);
+
+    return 1;
+}
+
+static int dfhack_penarray_clear(lua_State *L)
+{
+    PenArray *parr = check_penarray_native(L, 1);
+    parr->clear();
+    return 0;
+}
+
+static int dfhack_penarray_set_tile(lua_State *L)
+{
+    PenArray *parr = check_penarray_native(L, 1);
+    unsigned int x = luaL_checkint(L, 2);
+    unsigned int y = luaL_checkint(L, 3);
+    Pen pen;
+    Lua::CheckPen(L, &pen, 4);
+    parr->set_tile(x, y, pen);
+    return 0;
+}
+
+static int dfhack_penarray_draw(lua_State *L)
+{
+    PenArray *parr = check_penarray_native(L, 1);
+    unsigned int x = (unsigned int)luaL_checkint(L, 2);
+    unsigned int y = (unsigned int)luaL_checkint(L, 3);
+    unsigned int w = (unsigned int)luaL_checkint(L, 4);
+    unsigned int h = (unsigned int)luaL_checkint(L, 5);
+    unsigned int bufx = (unsigned int)luaL_optint(L, 6, 0);
+    unsigned int bufy = (unsigned int)luaL_optint(L, 7, 0);
+    parr->draw(x, y, w, h, bufx, bufy);
+    return 0;
+}
+
+static const luaL_Reg dfhack_penarray_funcs[] = {
+    { "new", dfhack_penarray_new },
+    { "clear", dfhack_penarray_clear },
+    { "set_tile", dfhack_penarray_set_tile },
+    { "draw", dfhack_penarray_draw },
+    { NULL, NULL }
+};
+
+static void OpenPenArray(lua_State *state)
+{
+    luaL_getsubtable(state, lua_gettop(state), "penarray");
+
+    lua_dup(state);
+    lua_rawsetp(state, LUA_REGISTRYINDEX, &DFHACK_PENARRAY_TOKEN);
+
+    luaL_setfuncs(state, dfhack_penarray_funcs, 0);
+
+    lua_pop(state, 1);
+}
+
 /********************
  * Random generator *
  ********************/
@@ -2516,6 +2598,7 @@ void OpenDFHackApi(lua_State *state)
     OpenPersistent(state);
     OpenMatinfo(state);
     OpenPen(state);
+    OpenPenArray(state);
     OpenRandom(state);
 
     LuaWrapper::SetFunctionWrappers(state, dfhack_module);

library/include/LuaTools.h

@@ -48,6 +48,7 @@ namespace DFHack {
     }
     namespace Screen {
         struct Pen;
+        struct PenArray;
     };
 }
 

library/include/modules/Screen.h

@@ -114,6 +114,19 @@ namespace DFHack
             Pen chtile(char ch, int tile) { Pen cp(*this); cp.ch = ch; cp.tile = tile; return cp; }
         };
 
+        class DFHACK_EXPORT PenArray {
+            Pen *buffer;
+            unsigned int dimx;
+            unsigned int dimy;
+        public:
+            PenArray(unsigned int bufwidth, unsigned int bufheight);
+            ~PenArray();
+            void clear();
+            void set_tile(unsigned int x, unsigned int y, Screen::Pen pen);
+            void draw(unsigned int x, unsigned int y, unsigned int width, unsigned int height,
+                unsigned int bufx = 0, unsigned int bufy = 0);
+        };
+
         struct DFHACK_EXPORT ViewRect {
             rect2d view, clip;
 

library/lua/dfhack.lua

@@ -264,6 +264,12 @@ function dfhack.random:__tostring()
     return "<random generator>"
 end
 
+dfhack.penarray.__index = dfhack.penarray
+
+function dfhack.penarray.__tostring()
+    return "<penarray>"
+end
+
 function dfhack.maps.getSize()
     local map = df.global.world.map
     return map.x_count_block, map.y_count_block, map.z_count_block

library/modules/Screen.cpp

@@ -65,6 +65,7 @@ using df::global::gview;
 using df::global::enabler;
 
 using Screen::Pen;
+using Screen::PenArray;
 
 using std::string;
 
@@ -436,6 +437,58 @@ df::interface_key Screen::charToKey(char code)
         return df::interface_key(interface_key::STRING_A128 + (val-128));
 }
 
+/*
+ * Pen array
+ */
+
+PenArray::PenArray(unsigned int bufwidth, unsigned int bufheight)
+    :dimx(bufwidth), dimy(bufheight)
+{
+    buffer = new Pen[bufwidth * bufheight];
+    clear();
+}
+
+PenArray::~PenArray()
+{
+    delete[] buffer;
+}
+
+void PenArray::clear()
+{
+    for (unsigned int x = 0; x < dimx; x++)
+    {
+        for (unsigned int y = 0; y < dimy; y++)
+        {
+            set_tile(x, y, Screen::Pen(0, 0, 0, 0, false));
+        }
+    }
+}
+
+void PenArray::set_tile(unsigned int x, unsigned int y, Screen::Pen pen)
+{
+    if (x < dimx && y < dimy)
+        buffer[(y * dimx) + x] = pen;
+}
+
+void PenArray::draw(unsigned int x, unsigned int y, unsigned int width, unsigned int height,
+                    unsigned int bufx, unsigned int bufy)
+{
+    if (!gps)
+        return;
+    for (unsigned int gridx = x; gridx < x + width; gridx++)
+    {
+        for (unsigned int gridy = y; gridy < y + height; gridy++)
+        {
+            if (gridx >= gps->dimx ||
+                gridy >= gps->dimy ||
+                gridx - x + bufx >= dimx ||
+                gridy - y + bufy >= dimy)
+                continue;
+            Screen::paintTile(buffer[((gridy - y + bufy) * dimx) + (gridx - x + bufx)], gridx, gridy);
+        }
+    }
+}
+
 /*
  * Base DFHack viewscreen.
  */