Map Renderer|Light Grid: Updated LightGrid implementation; addressed …

…limitations

Revised the LightGrid, re-implementing it in C++ with Doomsday 2.0
components. The internal design of this component is mostly unchanged
however.

Noteworthy changes:
* The grid is initialized automatically should it be enabled after
the map has already loaded.
* Significantly reduced memory requirements through the use of a sparse
grid of block references and a special "null-block".
* An instance of LightGrid is now owned by the GameMap rather than a
global "singleton".

doomsday/client/include/map/gamemap.h

@@ -31,6 +31,10 @@
 #include "p_particle.h"
 #include "Polyobj"
 
+#ifdef __CLIENT__
+#  include "render/r_lgrid.h"
+#endif
+
 class Vertex;
 class Line;
 class Sector;
@@ -76,6 +80,11 @@ struct clpolyobj_s;
 class GameMap
 {
 public:
+#ifdef __CLIENT__
+    /// Required light grid is missing. @ingroup errors
+    DENG2_ERROR(MissingLightGridError);
+#endif
+
     typedef QList<Vertex *> Vertexes;
     typedef QList<Sector *> Sectors;
     typedef QList<Line *> Lines;
@@ -603,6 +612,27 @@ class GameMap
 
 #ifdef __CLIENT__
     void buildSurfaceLists();
+
+    /**
+     * Returns @c true iff a LightGrid has been initialized for the map.
+     *
+     * @see lightGrid()
+     */
+    bool hasLightGrid();
+
+    /**
+     * Provides access to the light grid for the map.
+     *
+     * @see hasLightGrid()
+     */
+    de::LightGrid &lightGrid();
+
+    /**
+     * Initialize the ambient lighting grid (smoothed sector lighting).
+     * If the grid has already been initialized calling this will perform
+     * a full update.
+     */
+    void initLightGrid();
 #endif
 
     bool buildBsp();

doomsday/client/include/map/sector.h

@@ -43,7 +43,6 @@ class Surface;
  */
 ///@{
 #define SIF_VISIBLE             0x1 ///< Sector is visible on this frame.
-#define SIF_LIGHT_CHANGED       0x2
 
 // Flags to clear before each frame.
 #define SIF_FRAME_CLEAR         SIF_VISIBLE

doomsday/client/include/network/net_main.h

@@ -251,7 +251,11 @@ int             Net_TimeDelta(byte now, byte then);
 void            Net_Update(void);
 void            Net_ResetTimer(void);
 void            Net_Ticker(timespan_t time);
-void            Net_Drawer(void);
+
+/**
+ * Does drawing for the engine's HUD, not just the net.
+ */
+void Net_Drawer(void);
 
 boolean         Net_IsLocalPlayer(int pNum);
 

doomsday/client/include/render/r_lgrid.h

@@ -1,4 +1,4 @@
-/** @file r_lgrid.h
+/** @file render/r_lgrid.h Light Grid (Smoothed ambient sector lighting).
  *
  * @authors Copyright © 2003-2013 Jaakko Keränen <jaakko.keranen@iki.fi>
  * @authors Copyright © 2006-2013 Daniel Swanson <danij@dengine.net>
@@ -17,51 +17,108 @@
  * http://www.gnu.org/licenses</small>
  */
 
-/**
- * Smoothed ambient sector lighting.
- */
-
-#ifndef LIBDENG_REFRESH_LIGHT_GRID_H
-#define LIBDENG_REFRESH_LIGHT_GRID_H
+#ifndef DENG_RENDER_LIGHT_GRID_H
+#define DENG_RENDER_LIGHT_GRID_H
 
 #include "dd_types.h"
-#include "map/p_mapdata.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+#include <de/Vector>
 
-void LG_Register(void);
-void LG_InitForMap(void);
-void LG_Update(void);
-
-/**
- * Called when a setting is changed which affects the lightgrid.
- */
-void LG_MarkAllForUpdate(void);
+class GameMap;
+class Sector;
 
-void LG_SectorChanged(Sector* sector);
+namespace de {
 
 /**
- * Calculate the light color for a 3D point in the world.
+ * Simple global illumination method utilizing a 2D grid of light levels, achieving
+ * smoothed ambient sector lighting.
  *
- * @param point      3D point.
- * @param destColor  Evaluated color of the point (return value).
+ * @ingroup render
  */
-void LG_Evaluate(coord_t const point[3], float destColor[3]);
+class LightGrid
+{
+public:
+    /**
+     * Two dimensioned reference to a block in the grid [X, Y].
+     */
+    typedef Vector2i Ref;
 
-/**
- * Calculate the light level for a 3D point in the world.
- *
- * @param point  3D point.
- * @return  Evaluated light level of the point.
- */
-float LG_EvaluateLightLevel(coord_t const point[3]);
+    /**
+     * Linear reference to a block in the grid (X + Y * Grid Width).
+     */
+    typedef int Index;
+
+public:
+    /**
+     * Construct and initialize a new LightGrid for the specifed map.
+     *
+     * @note Initialization may take some time depending on the complexity of the map
+     * (world dimensions, number of sectors) and should therefore be done "off-line".
+     */
+    LightGrid(GameMap &map);
+
+    /**
+     * Register the console comands and variables of this module.
+     */
+    static void consoleRegister();
+
+    /**
+     * Update the grid by finding the strongest light source in each grid block.
+     * Should be called periodically to update/refresh the grid contents (e.g., when
+     * beginning a new render frame).
+     */
+    void update();
+
+    /**
+     * To be called when an engine variable which affects the lightgrid changes.
+     */
+    void markAllForUpdate();
+
+    /**
+     * Returns the dimensions of the light grid in blocks. For informational purposes.
+     */
+    Vector2i const &dimensions() const;
+
+    /**
+     * Returns the size of grid block in map coordinate space units. For informational
+     * purposes.
+     */
+    coord_t blockSize() const;
+
+    /**
+     * Determine the ambient light color for a point in the map coordinate space.
+     *
+     * @param point  3D point.
+     *
+     * @return  Evaluated color at the specified point.
+     */
+    Vector3f evaluate(Vector3d const &point);
+
+    /**
+     * Determine the ambient light level for a point in the map coordinate space.
+     *
+     * @param point  3D point.
+     *
+     * @return  Evaluated light level at the specified point.
+     */
+    float evaluateLightLevel(Vector3d const &point);
+
+    /**
+     * To be called when the ambient lighting properties in the sector change.
+     *
+     * @todo Replace with internal de::Observers based mechanism.
+     */
+    void sectorChanged(Sector &sector);
+
+    /**
+     * Draw the light grid debug visual.
+     */
+    void drawDebugVisual();
 
-void LG_Debug(void);
+private:
+    DENG2_PRIVATE(d)
+};
 
-#ifdef __cplusplus
-} // extern "C"
-#endif
+} // namespace de
 
-#endif // LIBDENG_REFRESH_LIGHT_GRID_H
+#endif // DENG_RENDER_LIGHT_GRID_H

doomsday/client/src/map/gamemap.cpp

@@ -20,6 +20,8 @@
 
 #include <cmath>
 
+#include <de/libdeng2.h>
+
 #include "de_base.h"
 #include "de_console.h"
 #include "de_play.h"
@@ -59,6 +61,8 @@ DENG2_PIMPL(GameMap)
 #ifdef __CLIENT__
     SurfaceSet decoratedSurfaces;
     SurfaceSet glowingSurfaces;
+
+    QScopedPointer<LightGrid> lightGrid;
 #endif
 
     coord_t skyFix[2]; // [floor, ceiling]
@@ -690,6 +694,36 @@ void GameMap::buildSurfaceLists()
     }
 }
 
+bool GameMap::hasLightGrid()
+{
+    return !d->lightGrid.isNull();
+}
+
+LightGrid &GameMap::lightGrid()
+{
+    if(!d->lightGrid.isNull())
+    {
+        return *d->lightGrid;
+    }
+    /// @throw MissingLightGrid Attempted with no LightGrid initialized.
+    throw MissingLightGridError("GameMap::lightGrid", "No light grid is initialized");
+}
+
+void GameMap::initLightGrid()
+{
+    // Disabled?
+    if(!Con_GetInteger("rend-bias-grid"))
+        return;
+
+    // Time to initialize the LightGrid?
+    if(d->lightGrid.isNull())
+    {
+        d->lightGrid.reset(new LightGrid(*this));
+    }
+    // Perform a full update right away.
+    d->lightGrid->update();
+}
+
 #endif // __CLIENT__
 
 de::Uri GameMap::uri() const

doomsday/client/src/map/p_data.cpp

@@ -228,8 +228,7 @@ DENG_EXTERN_C boolean P_LoadMap(char const *uriCString)
         R_InitShadowProjectionListsForMap(); // Projected mobj shadows.
         VL_InitForMap(); // Converted vlights (from lumobjs) management.
 
-        // Initialize the lighting grid.
-        LG_InitForMap();
+        theMap->initLightGrid();
 
         R_InitRendPolyPools();
 #endif

doomsday/client/src/map/p_dmu.cpp

@@ -833,15 +833,13 @@ static void updateSector(Sector &sector, bool forceUpdate = false)
         sector._lightColor[1] != sector._oldLightColor[1] ||
         sector._lightColor[2] != sector._oldLightColor[2]))
     {
-        sector._frameFlags |= SIF_LIGHT_CHANGED;
         sector._oldLightLevel = sector._lightLevel;
         sector._oldLightColor = sector._lightColor;
 
-        LG_SectorChanged(&sector);
-    }
-    else
-    {
-        sector._frameFlags &= ~SIF_LIGHT_CHANGED;
+        if(theMap->hasLightGrid())
+        {
+            theMap->lightGrid().sectorChanged(sector);
+        }
     }
 #endif
 }

doomsday/client/src/network/net_main.cpp

@@ -741,18 +741,9 @@ void Net_DrawDemoOverlay(void)
 
 #endif // __CLIENT__
 
-/**
- * Does drawing for the engine's HUD, not just the net.
- */
-void Net_Drawer(void)
+void Net_Drawer()
 {
 #ifdef __CLIENT__
-    // Draw the Shadow Bias Editor HUD (if it is active).
-    SBE_DrawHUD();
-
-    // Draw lightgrid debug display.
-    LG_Debug();
-
     // Draw the blockmap debug display.
     Rend_BlockmapDebug();