Refactor|Client: Revising game view drawing and compositing

The rendered game view is now drawn to the window FBO as part of
view layers composition.

Todo: Unlit floors not rendered correctly, depth/stencil issue?

doomsday/apps/client/include/clientapp.h

@@ -35,6 +35,8 @@
 #include "busyrunner.h"
 #include "world/clientserverworld.h"
 
+class ClientPlayer;
+
 /**
  * The client application.
  */
@@ -60,6 +62,9 @@ class ClientApp : public de::BaseGuiApp, public DoomsdayApp
             de::String const &userMessageIfIncompatible,
             std::function<void ()> finalizeFunc) override;
 
+    de::LoopResult forLocalPlayers(std::function<de::LoopResult (ClientPlayer &)> func);
+
+public:
     /**
      * Reports a new alert to the user.
      *
@@ -68,7 +73,6 @@ class ClientApp : public de::BaseGuiApp, public DoomsdayApp
      */
     static void alert(de::String const &msg, de::LogEntry::Level level = de::LogEntry::Message);
 
-public:
     static ClientApp &          app();
     static BusyRunner &         busyRunner();
     static Updater &            updater();

doomsday/apps/client/include/render/viewports.h

@@ -134,6 +134,8 @@ viewport_t const *R_CurrentViewPort();
  */
 void R_UseViewPort(viewport_t const *vp);
 
+void R_UseViewPort(int consoleNum);
+
 void R_UpdateViewer(int consoleNum);
 
 void R_ResetViewer();

doomsday/apps/client/include/ui/viewcompositor.h

@@ -76,9 +76,9 @@ class ViewCompositor
      * Note that the existing contents of the game view framebuffer are used as-is; the
      * game view needs to be redrawn separately beforehand, if needed.
      *
-     * @param playerNum  Player number.
+     * @param rect  Rectangle in which to draw the layers.
      */
-    void drawCompositedLayers();
+    void drawCompositedLayers(de::Rectanglei const &rect);
 
 private:
     DENG2_PRIVATE(d)

doomsday/apps/client/src/clientapp.cpp

@@ -678,6 +678,24 @@ void ClientApp::checkPackageCompatibility(StringList const &packageIds,
     }
 }
 
+LoopResult ClientApp::forLocalPlayers(std::function<LoopResult (ClientPlayer &)> func)
+{
+    auto const &players = DoomsdayApp::players();
+    for (int i = 0; i < players.count(); ++i)
+    {
+        ClientPlayer &player = players.at(i).as<ClientPlayer>();
+        if (player.isInGame() &&
+            player.publicData().flags & DDPF_LOCAL)
+        {
+            if (auto result = func(player))
+            {
+                return result;
+            }
+        }
+    }
+    return LoopContinue;
+}
+
 void ClientApp::alert(String const &msg, LogEntry::Level level)
 {
     if (ClientWindow::mainExists())

doomsday/apps/client/src/render/viewports.cpp

@@ -702,14 +702,14 @@ void R_UseViewPort(viewport_t const *vp)
     if (!vp)
     {
         currentViewport = nullptr;
-        /*ClientWindow::main().game().glApplyViewport(
+        ClientWindow::main().game().glApplyViewport(
                 Rectanglei::fromSize(Vector2i(DENG_GAMEVIEW_X, DENG_GAMEVIEW_Y),
-                                     Vector2ui(DENG_GAMEVIEW_WIDTH, DENG_GAMEVIEW_HEIGHT)));*/
+                                     Vector2ui(DENG_GAMEVIEW_WIDTH, DENG_GAMEVIEW_HEIGHT)));
     }
     else
     {
         currentViewport = const_cast<viewport_t *>(vp);
-        //ClientWindow::main().game().glApplyViewport(vp->geometry);
+        ClientWindow::main().game().glApplyViewport(vp->geometry);
     }
 }
 
@@ -1056,6 +1056,7 @@ void R_RenderViewPort(int playerNum)
     dint const oldDisplay = displayPlayer;
     displayPlayer = vp->console;
     R_UseViewPort(vp);
+    //currentViewport = vp;
 
     if(displayPlayer < 0 || (DD_Player(displayPlayer)->publicData().flags & DDPF_UNDEFINED_ORIGIN))
     {
@@ -1085,9 +1086,10 @@ void R_RenderViewPort(int playerNum)
     //case Player3DViewLayer:
 
     R_UpdateViewer(vp->console);
+
     //LensFx_BeginFrame(vp->console);
 
-    gx.DrawViewPort(localNum, &vpGeometry, &vdWindow, displayPlayer, 0/*layer #0*/);
+    gx.DrawViewPort(localNum, &vpGeometry, &vdWindow, displayPlayer, /* layer: */ 0);
 
         //LensFx_EndFrame();
         //break;
@@ -1098,7 +1100,7 @@ void R_RenderViewPort(int playerNum)
         break;
 
     case HUDLayer:
-        gx.DrawViewPort(p, &vpGeometry, &vdWindow, displayPlayer, 1/*layer #1*/);
+        gx.DrawViewPort(p, &vpGeometry, &vdWindow, displayPlayer, /* layer: */ 1);
         break;
     }
 #endif
@@ -1122,6 +1124,8 @@ void R_RenderViewPort(int playerNum)
     // Restore things back to normal.
     displayPlayer = oldDisplay;
     R_UseViewPort(nullptr);
+
+    //currentViewport = nullptr;
 }
 
 #if 0
@@ -1489,3 +1493,16 @@ void Viewports_Register()
 
     C_CMD("viewgrid", "ii", ViewGrid);
 }
+
+void R_UseViewPort(int consoleNum)
+{
+    int local = P_ConsoleToLocal(consoleNum);
+    if (local >= 0)
+    {
+        R_UseViewPort(&viewportOfLocalPlayer[local]);
+    }
+    else
+    {
+        R_UseViewPort(nullptr);
+    }
+}

doomsday/apps/client/src/ui/viewcompositor.cpp

@@ -17,9 +17,15 @@
  */
 
 #include "ui/viewcompositor.h"
+#include "ui/clientwindow.h"
+#include "render/viewports.h"
+#include "world/p_players.h"
 #include "api_render.h"
+#include "clientapp.h"
 
 #include <de/GLState>
+#include <de/GLShaderBank>
+#include <de/Drawable>
 
 using namespace de;
 
@@ -32,11 +38,20 @@ DENG2_PIMPL(ViewCompositor)
     /// game HUD.
     GLTextureFramebuffer viewFramebuf;
 
+    Drawable frameDrawable;
+    GLUniform uMvpMatrix { "uMvpMatrix", GLUniform::Mat4 };
+    GLUniform uFrameTex  { "uTex", GLUniform::Sampler2D };
+
     Impl(Public *i)
         : Base(i)
         , viewFramebuf(Image::RGBA_8888)
     {}
 
+    ~Impl()
+    {
+        DENG2_ASSERT(!frameDrawable.isReady()); // deinited earlier
+    }
+
     GLFramebuffer::Size framebufferSize() const
     {
         // TODO: Factor in pixel density and scaled-down window size.
@@ -50,6 +65,28 @@ DENG2_PIMPL(ViewCompositor)
     {
         viewFramebuf.resize(framebufferSize());
         viewFramebuf.glInit();
+
+        if (!frameDrawable.isReady())
+        {
+            ClientApp::shaders().build(frameDrawable.program(), "generic.texture")
+                    << uMvpMatrix
+                    << uFrameTex;
+
+            using VBuf = GuiWidget::DefaultVertexBuf;
+
+            auto *vbuf = new VBuf;
+            frameDrawable.addBuffer(vbuf);
+
+            VBuf::Builder verts;
+            verts.makeQuad(Rectanglef(0, 0, 1, 1), Rectanglef(0, 1, 1, -1));
+            vbuf->setVertices(gl::TriangleStrip, verts, gl::Static);
+        }
+    }
+
+    void glDeinit()
+    {
+        viewFramebuf.glDeinit();
+        frameDrawable.clear();
     }
 };
 
@@ -64,7 +101,7 @@ void ViewCompositor::setPlayerNumber(int playerNum)
 
 void ViewCompositor::glDeinit()
 {
-    d->viewFramebuf.glDeinit();
+    d->glDeinit();
 }
 
 void ViewCompositor::renderGameView(std::function<void (int)> renderFunc)
@@ -76,8 +113,9 @@ void ViewCompositor::renderGameView(std::function<void (int)> renderFunc)
             .setViewport(Rectangleui::fromSize(d->viewFramebuf.size()))
             .apply();
 
-    d->viewFramebuf.clear(GLFramebuffer::ColorDepth);
+    d->viewFramebuf.clear(GLFramebuffer::ColorDepthStencil);
 
+    // Rendering is done by the caller-provided callback.
     renderFunc(d->playerNum);
 
     GLState::pop()
@@ -94,7 +132,39 @@ GLTextureFramebuffer const &ViewCompositor::gameView() const
     return d->viewFramebuf;
 }
 
-void ViewCompositor::drawCompositedLayers()
+void ViewCompositor::drawCompositedLayers(Rectanglei const &rect)
 {
+    DENG2_ASSERT(d->frameDrawable.isReady());
+
+    GLState::push()
+            .setBlend    (false)
+            .setDepthTest(false)
+            .setCull     (gl::None);
+
+    // First the game view (using the previously rendered texture).
+    d->uFrameTex  = d->viewFramebuf.colorTexture();
+    d->uMvpMatrix = ClientWindow::main().root().projMatrix2D() *
+                    Matrix4f::scaleThenTranslate(rect.size(), rect.topLeft);
+    d->frameDrawable.draw();
+
+    // View border around the game view.
+    auto const oldDisplayPlayer = displayPlayer;
+    displayPlayer = d->playerNum;
+
+    R_UseViewPort(d->playerNum);
+
+    //R_RenderPlayerViewBorder();
+
+    // Game HUD.
+
+    // Finale.
+
+    // Non-map game screens.
+
+    // Legacy engine/debug UIs (stuff from the old Net_Drawer).
+
+    R_UseViewPort(nullptr);
+    displayPlayer = oldDisplayPlayer;
 
+    GLState::pop().apply();
 }