optimized light drawing: process only "possible lit panels" instead of all walls

diff --git a/src/game/g_game.pas b/src/game/g_game.pas
index 693798382f8943bdb8cfbf2858d7fca05e9e4af8..8aa98c68cef328bdf3623d39f78f0863865aca12 100644 (file)
--- a/src/game/g_game.pas
+++ b/src/game/g_game.pas
@@ -2634,6 +2634,7 @@ var
   //R: TRect;
   lln: Integer;
   lx, ly, lrad: Integer;
+  ltminx, ltminy, ltmaxx, ltmaxy: Integer;
 begin
   if (p = nil) or (p.FDummy) then
   begin
@@ -2739,54 +2740,82 @@ begin
 
   if gwin_has_stencil and (g_dynLightCount > 0) then
   begin
-    // setup OpenGL parameters
-    glStencilMask($FFFFFFFF);
-    glStencilFunc(GL_ALWAYS, 0, $FFFFFFFF);
-    glEnable(GL_STENCIL_TEST);
-    glEnable(GL_SCISSOR_TEST);
-    glClear(GL_STENCIL_BUFFER_BIT);
-    glStencilFunc(GL_EQUAL, 0, $ff);
+    // get light bounds
+    ltminx := $3fffffff;
+    ltminy := $3fffffff;
+    ltmaxx := -$3fffffff;
+    ltmaxy := -$3fffffff;
 
     for lln := 0 to g_dynLightCount-1 do
     begin
-      lx := g_dynLights[lln].x;
-      ly := g_dynLights[lln].y;
+      lx := g_dynLights[lln].x-sX;
+      ly := g_dynLights[lln].y-sY;
       lrad := g_dynLights[lln].radius;
       if lrad < 3 then continue;
-      // set scissor to optimize drawing
-      glScissor((lx-sX)-lrad+2, gPlayerScreenSize.Y-(ly-sY)-lrad-1+2, lrad*2-4, lrad*2-4);
-      // clear stencil buffer
-      //glClear(GL_STENCIL_BUFFER_BIT); //!!!
-      glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
-      // draw extruded panels
-      glDisable(GL_TEXTURE_2D);
-      glDisable(GL_BLEND);
-      glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE); // no need to modify color buffer
-      if (lrad > 4) then g_Map_DrawPanelShadowVolumes(lx, ly, lrad);
-      // render light texture
-      glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE); // modify color buffer
-      //glStencilOp(GL_KEEP, GL_KEEP, GL_KEEP);
-      glStencilOp(GL_ZERO, GL_ZERO, GL_ZERO); // draw light, and clear stencil buffer
-      // blend it
-      glEnable(GL_BLEND);
-      glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-      glEnable(GL_TEXTURE_2D);
-      // color and opacity
-      glColor4f(g_dynLights[lln].r, g_dynLights[lln].g, g_dynLights[lln].b, g_dynLights[lln].a);
-      glBindTexture(GL_TEXTURE_2D, g_Texture_Light());
-      glBegin(GL_QUADS);
-        glTexCoord2f(0.0, 0.0); glVertex2i(lx-lrad, ly-lrad); // top-left
-        glTexCoord2f(1.0, 0.0); glVertex2i(lx+lrad, ly-lrad); // top-right
-        glTexCoord2f(1.0, 1.0); glVertex2i(lx+lrad, ly+lrad); // bottom-right
-        glTexCoord2f(0.0, 1.0); glVertex2i(lx-lrad, ly+lrad); // bottom-left
-      glEnd();
+
+      if lx+lrad < 0 then continue;
+      if ly+lrad < 0 then continue;
+      if lx-lrad >= gPlayerScreenSize.X then continue;
+      if ly-lrad >= gPlayerScreenSize.Y then continue;
+
+      lx := lx+sX;
+      ly := ly+sY;
+
+      if ltminx > lx-lrad then ltminx := lx-lrad;
+      if ltminy > ly-lrad then ltminy := ly-lrad;
+      if ltmaxx < lx+lrad then ltmaxx := lx+lrad;
+      if ltmaxy < ly+lrad then ltmaxy := ly+lrad;
     end;
 
-    // done
-    glDisable(GL_STENCIL_TEST);
-    glDisable(GL_BLEND);
-    glDisable(GL_SCISSOR_TEST);
-    glScissor(0, 0, sWidth, sHeight);
+    if g_Map_BuildPLP(ltminx, ltminy, ltmaxx, ltmaxy) then
+    begin
+      // setup OpenGL parameters
+      glStencilMask($FFFFFFFF);
+      glStencilFunc(GL_ALWAYS, 0, $FFFFFFFF);
+      glEnable(GL_STENCIL_TEST);
+      glEnable(GL_SCISSOR_TEST);
+      glClear(GL_STENCIL_BUFFER_BIT);
+      glStencilFunc(GL_EQUAL, 0, $ff);
+
+      for lln := 0 to g_dynLightCount-1 do
+      begin
+        lx := g_dynLights[lln].x;
+        ly := g_dynLights[lln].y;
+        lrad := g_dynLights[lln].radius;
+        if lrad < 3 then continue;
+        // set scissor to optimize drawing
+        glScissor((lx-sX)-lrad+2, gPlayerScreenSize.Y-(ly-sY)-lrad-1+2, lrad*2-4, lrad*2-4);
+        // no need to clear stencil buffer, light blitting will do it for us
+        glStencilOp(GL_KEEP, GL_KEEP, GL_INCR);
+        // draw extruded panels
+        glDisable(GL_TEXTURE_2D);
+        glDisable(GL_BLEND);
+        glColorMask(GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE); // no need to modify color buffer
+        if (lrad > 4) then g_Map_DrawPanelShadowVolumes(lx, ly, lrad);
+        // render light texture
+        glColorMask(GL_TRUE, GL_TRUE, GL_TRUE, GL_TRUE); // modify color buffer
+        glStencilOp(GL_ZERO, GL_ZERO, GL_ZERO); // draw light, and clear stencil buffer
+        // blend it
+        glEnable(GL_BLEND);
+        glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+        glEnable(GL_TEXTURE_2D);
+        // color and opacity
+        glColor4f(g_dynLights[lln].r, g_dynLights[lln].g, g_dynLights[lln].b, g_dynLights[lln].a);
+        glBindTexture(GL_TEXTURE_2D, g_Texture_Light());
+        glBegin(GL_QUADS);
+          glTexCoord2f(0.0, 0.0); glVertex2i(lx-lrad, ly-lrad); // top-left
+          glTexCoord2f(1.0, 0.0); glVertex2i(lx+lrad, ly-lrad); // top-right
+          glTexCoord2f(1.0, 1.0); glVertex2i(lx+lrad, ly+lrad); // bottom-right
+          glTexCoord2f(0.0, 1.0); glVertex2i(lx-lrad, ly+lrad); // bottom-left
+        glEnd();
+      end;
+
+      // done
+      glDisable(GL_STENCIL_TEST);
+      glDisable(GL_BLEND);
+      glDisable(GL_SCISSOR_TEST);
+      glScissor(0, 0, sWidth, sHeight);
+    end;
   end;
 
   g_Map_DrawPanels(PANEL_FORE);

diff --git a/src/game/g_map.pas b/src/game/g_map.pas
index aceb7e3d2069d8b5c95c550b044aa95e4fa37cea..f8599dd3435fcf8e7319685c0b5b71e67b483d47 100644 (file)
--- a/src/game/g_map.pas
+++ b/src/game/g_map.pas
@@ -92,6 +92,8 @@ function g_Map_PanelForPID(PanelID: Integer; var PanelArrayID: Integer): PPanel;
 procedure g_Map_SaveState(Var Mem: TBinMemoryWriter);
 procedure g_Map_LoadState(Var Mem: TBinMemoryReader);
 
+// build "possibly lit panels" index, so we can avoid looping over all level panels again and again
+function g_Map_BuildPLP (ltminx, ltminy, ltmaxx, ltmaxy: Integer): Boolean; // returns `false` if no patels lit
 procedure g_Map_DrawPanelShadowVolumes(lightX: Integer; lightY: Integer; radius: Integer);
 
 const
@@ -1794,8 +1796,41 @@ begin
   end;
 end;
 
+var
+  plpset: array of Integer = nil; // potentially lit panels
+  plpcount: Integer; // to avoid constant reallocations
+
+function g_Map_BuildPLP (ltminx, ltminy, ltmaxx, ltmaxy: Integer): Boolean;
+var
+  idx: Integer;
+  panels: TPanelArray;
+begin
+  panels := gWalls;
+  plpcount := 0;
+  if (ltminx < ltmaxx) and (ltminy < ltmaxy) then
+  begin
+    if panels <> nil then
+    begin
+      for idx := 0 to High(panels) do
+      begin
+        if (panels[idx].Width < 1) or (panels[idx].Height < 1) then continue;
+        if (panels[idx].X+panels[idx].Width <= ltminx) then continue;
+        if (panels[idx].Y+panels[idx].Height <= ltminy) then continue;
+        if (panels[idx].X > ltmaxx) then continue;
+        if (panels[idx].Y > ltmaxy) then continue;
+        if plpcount = length(plpset) then SetLength(plpset, plpcount+32768);
+        plpset[plpcount] := idx;
+        Inc(plpcount);
+      end;
+      //e_WriteLog(Format('%d panels left out of %d', [plpcount, Length(panels)]), MSG_NOTIFY);
+    end;
+  end;
+  result := (plpcount > 0);
+end;
+
 procedure g_Map_DrawPanelShadowVolumes(lightX: Integer; lightY: Integer; radius: Integer);
 
+  (* old
   procedure drawPanels (var panels: TPanelArray);
   var
     a: Integer;
@@ -1808,10 +1843,18 @@ procedure g_Map_DrawPanelShadowVolumes(lightX: Integer; lightY: Integer; radius:
       end;
     end;
   end;
-
+  *)
+var
+  idx: Integer;
 begin
+  (*
   drawPanels(gWalls);
   //drawPanels(gRenderForegrounds);
+  *)
+  for idx := 0 to plpcount-1 do
+  begin
+    gWalls[plpset[idx]].DrawShadowVolume(lightX, lightY, radius);
+  end;
 end;
 
 procedure g_Map_DrawBack(dx, dy: Integer);