source/renderer/OverlayRenderer.h

   1 /* Copyright (C) 2013 Wildfire Games.
   2  * This file is part of 0 A.D.
   3  *
   4  * 0 A.D. is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * 0 A.D. is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifndef INCLUDED_OVERLAYRENDERER
  19 #define INCLUDED_OVERLAYRENDERER
  20
  21 #include "graphics/ShaderManager.h"
  22
  23 struct SOverlayLine;
  24 struct SOverlayTexturedLine;
  25 struct SOverlaySprite;
  26 struct SOverlayQuad;
  27 struct SOverlaySphere;
  28 class CCamera;
  29
  30 struct OverlayRendererInternals;
  31
  32 /**
  33  * Class OverlayRenderer: Render various bits of data that overlay the
  34  * game world (selection circles, health bars, etc).
  35  */
  36 class OverlayRenderer
  37 {
  38         NONCOPYABLE(OverlayRenderer);
  39
  40 public:
  41         OverlayRenderer();
  42         ~OverlayRenderer();
  43
  44         /**
  45          * Performs one-time initialization. Called by CRenderer::Open after graphics
  46          * capabilities and the shader path have been determined (notably VBO support).
  47          */
  48         void Initialize();
  49
  50         /**
  51          * Add a line overlay for rendering in this frame.
  52          * @param overlay Must be non-null. The pointed-to object must remain valid at least
  53          *                until the end of the frame.
  54          */
  55         void Submit(SOverlayLine* overlay);
  56
  57         /**
  58          * Add a textured line overlay for rendering in this frame.
  59          * @param overlay Must be non-null. The pointed-to object must remain valid at least
  60          *                until the end of the frame.
  61          */
  62         void Submit(SOverlayTexturedLine* overlay);
  63
  64         /**
  65          * Add a sprite overlay for rendering in this frame.
  66          * @param overlay Must be non-null. The pointed-to object must remain valid at least
  67          *                until the end of the frame.
  68          */
  69         void Submit(SOverlaySprite* overlay);
  70
  71         /**
  72          * Add a textured quad overlay for rendering in this frame.
  73          * @param overlay Must be non-null. The pointed-to object must remain valid at least
  74          *                until the end of the frame.
  75          */
  76         void Submit(SOverlayQuad* overlay);
  77
  78         /**
  79          * Add a sphere overlay for rendering in this frame.
  80          * @param overlay Must be non-null. The pointed-to object must remain valid at least
  81          *                until the end of the frame.
  82          */
  83         void Submit(SOverlaySphere* overlay);
  84
  85         /**
  86          * Prepare internal data structures for rendering.
  87          * Must be called after all Submit calls for a frame, and before
  88          * any rendering calls.
  89          */
  90         void PrepareForRendering();
  91
  92         /**
  93          * Reset the list of submitted overlays.
  94          */
  95         void EndFrame();
  96
  97         /**
  98          * Render all the submitted overlays that are embedded in the world
  99          * (i.e. rendered behind other objects in the normal 3D way)
 100          * and should be drawn before water (i.e. may be visible under the water)
 101          */
 102         void RenderOverlaysBeforeWater();
 103
 104         /**
 105          * Render all the submitted overlays that are embedded in the world
 106          * (i.e. rendered behind other objects in the normal 3D way)
 107          * and should be drawn after water (i.e. may be visible on top of the water)
 108          */
 109         void RenderOverlaysAfterWater();
 110
 111         /**
 112          * Render all the submitted overlays that should appear on top of everything
 113          * in the world.
 114          * @param viewCamera camera to be used for billboard computations
 115          */
 116         void RenderForegroundOverlays(const CCamera& viewCamera);
 117
 118         /// Small vertical offset of overlays from terrain to prevent visual glitches
 119         static const float OVERLAY_VOFFSET;
 120
 121 private:
 122
 123         /**
 124          * Helper method; renders all overlay lines currently registered in the internals. Batch-
 125          * renders textured overlay lines batched according to their visibility status by delegating
 126          * to RenderTexturedOverlayLines(CShaderProgramPtr, bool).
 127          */
 128         void RenderTexturedOverlayLines();
 129
 130         /**
 131          * Helper method; renders those overlay lines currently registered in the internals (i.e.
 132          * in m->texlines) for which the 'always visible' flag equals @p alwaysVisible. Used for
 133          * batch rendering the overlay lines according to their alwaysVisible status, as this
 134          * requires a separate shader to be used.
 135          */
 136         void RenderTexturedOverlayLines(CShaderProgramPtr shader, bool alwaysVisible);
 137
 138         /**
 139          * Helper method; batch-renders all registered quad overlays, batched by their texture for effiency.
 140          */
 141         void RenderQuadOverlays();
 142
 143         /**
 144          * Helper method; batch-renders all sphere quad overlays.
 145          */
 146          void RenderSphereOverlays();
 147
 148 private:
 149         OverlayRendererInternals* m;
 150 };
 151
 152 #endif // INCLUDED_OVERLAYRENDERER