source/renderer/RenderModifiers.h

   1 /* Copyright (C) 2022 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 /*
  19  * RenderModifiers can affect the fragment stage behaviour of some
  20  * ModelRenderers. This file defines some common RenderModifiers in
  21  * addition to the base class.
  22  *
  23  * TODO: See comment in CRendererInternals::Models - we no longer use multiple
  24  * subclasses of RenderModifier, so most of the stuff here is unnecessary
  25  * abstraction which should probably be cleaned up.
  26  */
  27
  28 #ifndef INCLUDED_RENDERMODIFIERS
  29 #define INCLUDED_RENDERMODIFIERS
  30
  31 #include "ModelRenderer.h"
  32 #include "graphics/Color.h"
  33 #include "graphics/ShaderProgram.h"
  34 #include "graphics/ShaderTechnique.h"
  35 #include "graphics/Texture.h"
  36
  37 class CLightEnv;
  38 class CModel;
  39 class ShadowMap;
  40
  41 /**
  42  * Class RenderModifier: Some ModelRenderer implementations provide vertex
  43  * management behaviour but allow fragment stages to be modified by a plugged in
  44  * RenderModifier.
  45  *
  46  * You should use RenderModifierPtr when referencing RenderModifiers.
  47  */
  48 class RenderModifier
  49 {
  50 public:
  51         RenderModifier() { }
  52         virtual ~RenderModifier() { }
  53
  54         /**
  55          * BeginPass: Setup OpenGL for the given rendering pass.
  56          *
  57          * Must be implemented by derived classes.
  58          */
  59         virtual void BeginPass(
  60                 Renderer::Backend::IDeviceCommandContext* deviceCommandContext,
  61                 Renderer::Backend::IShaderProgram* shader) = 0;
  62
  63         /**
  64          * PrepareModel: Called before rendering the given model.
  65          *
  66          * Default behaviour does nothing.
  67          *
  68          * @param model The model that is about to be rendered.
  69          */
  70         virtual void PrepareModel(
  71                 Renderer::Backend::IDeviceCommandContext* deviceCommandContext,
  72                 CModel* model) = 0;
  73 };
  74
  75
  76 /**
  77  * Class LitRenderModifier: Abstract base class for RenderModifiers that apply
  78  * a shadow map.
  79  * LitRenderModifiers expect the diffuse brightness in the primary color (instead of ambient + diffuse).
  80  */
  81 class LitRenderModifier : public RenderModifier
  82 {
  83 public:
  84         LitRenderModifier();
  85         ~LitRenderModifier();
  86
  87         /**
  88          * SetShadowMap: Set the shadow map that will be used for rendering.
  89          * Must be called by the user of the RenderModifier.
  90          *
  91          * The shadow map must be non-null and use depth texturing, or subsequent rendering
  92          * using this RenderModifier will fail.
  93          *
  94          * @param shadow the shadow map
  95          */
  96         void SetShadowMap(const ShadowMap* shadow);
  97
  98         /**
  99          * SetLightEnv: Set the light environment that will be used for rendering.
 100          * Must be called by the user of the RenderModifier.
 101          *
 102          * @param lightenv the light environment (must be non-null)
 103          */
 104         void SetLightEnv(const CLightEnv* lightenv);
 105
 106         const ShadowMap* GetShadowMap() const { return m_Shadow; }
 107         const CLightEnv* GetLightEnv() const { return m_LightEnv; }
 108
 109 private:
 110         const ShadowMap* m_Shadow;
 111         const CLightEnv* m_LightEnv;
 112 };
 113
 114 /**
 115  * A RenderModifier that sets uniforms and textures appropriately for rendering models.
 116  */
 117 class ShaderRenderModifier : public LitRenderModifier
 118 {
 119 public:
 120         ShaderRenderModifier();
 121
 122         // Implementation
 123         void BeginPass(
 124                 Renderer::Backend::IDeviceCommandContext* deviceCommandContext,
 125                 Renderer::Backend::IShaderProgram* shader) override;
 126         void PrepareModel(
 127                 Renderer::Backend::IDeviceCommandContext* deviceCommandContext,
 128                 CModel* model) override;
 129
 130 private:
 131         int32_t m_BindingInstancingTransform = -1;
 132         int32_t m_BindingShadingColor = -1;
 133         int32_t m_BindingPlayerColor = -1;
 134
 135         CColor m_ShadingColor, m_PlayerColor;
 136 };
 137
 138 #endif // INCLUDED_RENDERMODIFIERS