Merge branch 'moo-bitch-get-out-my-hay' into 'master'

Don't use FFP-friendly texture image units for shadow maps

Closes #7102

See merge request OpenMW/openmw!2682

components/sceneutil/mwshadowtechnique.cpp

@@ -537,9 +537,6 @@ MWShadowTechnique::ShadowData::ShadowData(MWShadowTechnique::ViewDependentData*
 
     bool debug = settings->getDebugDraw();
 
-    // set up texgen
-    _texgen = new osg::TexGen;
-
     // set up the texture
     _texture = new osg::Texture2D;
 
@@ -994,8 +991,6 @@ void SceneUtil::MWShadowTechnique::copyShadowMap(osgUtil::CullVisitor& cv, ViewD
         sdl.push_back(lhs_sd);
     }
 
-    assignTexGenSettings(cv, lhs);
-
     if (lhs->_numValidShadows > 0)
     {
         prepareStateSetForRenderingShadow(*lhs, cv.getTraversalNumber());
@@ -1007,13 +1002,6 @@ void SceneUtil::MWShadowTechnique::setCustomFrustumCallback(CustomFrustumCallbac
     _customFrustumCallback = cfc;
 }
 
-void SceneUtil::MWShadowTechnique::assignTexGenSettings(osgUtil::CullVisitor& cv, ViewDependentData* vdd)
-{
-    for (const auto& sd : vdd->getShadowDataList())
-    {
-        assignTexGenSettings(&cv, sd->_camera, sd->_textureUnit, sd->_texgen);
-    }
-}
 
 void MWShadowTechnique::update(osg::NodeVisitor& nv)
 {
@@ -1035,7 +1023,7 @@ void MWShadowTechnique::cull(osgUtil::CullVisitor& cv)
             int endUnit = baseUnit + settings->getNumShadowMapsPerLight();
             for (int i = baseUnit; i < endUnit; ++i)
             {
-                dummyState->setTextureAttributeAndModes(i, _fallbackShadowMapTexture, osg::StateAttribute::ON);
+                dummyState->setTextureAttribute(i, _fallbackShadowMapTexture, osg::StateAttribute::ON);
                 dummyState->addUniform(new osg::Uniform(("shadowTexture" + std::to_string(i - baseUnit)).c_str(), i));
                 dummyState->addUniform(new osg::Uniform(("shadowTextureUnit" + std::to_string(i - baseUnit)).c_str(), i));
             }
@@ -1524,7 +1512,10 @@ void MWShadowTechnique::cull(osgUtil::CullVisitor& cv)
                     for (const auto & uniform : _uniforms[cv.getTraversalNumber() % 2])
                     {
                         if (uniform->getName() == validRegionUniformName)
+                        {
                             validRegionUniform = uniform;
+                            break;
+                        }
                     }
 
                     if (!validRegionUniform)
@@ -1548,7 +1539,33 @@ void MWShadowTechnique::cull(osgUtil::CullVisitor& cv)
  
             // 4.4 compute main scene graph TexGen + uniform settings + setup state
             //
-            assignTexGenSettings(&cv, camera.get(), textureUnit, sd->_texgen.get());
+            {
+                osg::Matrix shadowSpaceMatrix = cv.getCurrentCamera()->getInverseViewMatrix() *
+                    camera->getViewMatrix() *
+                    camera->getProjectionMatrix() *
+                    osg::Matrix::translate(1.0,1.0,1.0) *
+                    osg::Matrix::scale(0.5,0.5,0.5);
+
+                std::string shadowSpaceUniformName = "shadowSpaceMatrix" + std::to_string(sm_i);
+                osg::ref_ptr<osg::Uniform> shadowSpaceUniform;
+
+                for (const auto & uniform : _uniforms[cv.getTraversalNumber() % 2])
+                {
+                    if (uniform->getName() == shadowSpaceUniformName)
+                    {
+                        shadowSpaceUniform = uniform;
+                        break;
+                    }
+                }
+
+                if (!shadowSpaceUniform)
+                {
+                    shadowSpaceUniform = new osg::Uniform(osg::Uniform::FLOAT_MAT4, shadowSpaceUniformName);
+                    _uniforms[cv.getTraversalNumber() % 2].push_back(shadowSpaceUniform);
+                }
+
+                shadowSpaceUniform->set(shadowSpaceMatrix);
+            }
 
             // mark the light as one that has active shadows and requires shaders
             pl.textureUnits.push_back(textureUnit);
@@ -1556,14 +1573,7 @@ void MWShadowTechnique::cull(osgUtil::CullVisitor& cv)
             // pass on shadow data to ShadowDataList
             sd->_textureUnit = textureUnit;
 
-            if (textureUnit >= 8)
-            {
-                OSG_NOTICE<<"Shadow texture unit is invalid for texgen, will not be used."<<std::endl;
-            }
-            else
-            {
             sdl.push_back(sd);
-            }
 
             // increment counters.
             ++textureUnit;
@@ -1764,7 +1774,7 @@ void MWShadowTechnique::createShaders()
     // Always use the GL_ALWAYS shader as the shadows bin will change it if necessary
     _shadowCastingStateSet->setAttributeAndModes(_castingPrograms[GL_ALWAYS - GL_NEVER], osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
     // The casting program uses a sampler, so to avoid undefined behaviour, we must bind a dummy texture in case no other is supplied
-    _shadowCastingStateSet->setTextureAttributeAndModes(0, _fallbackBaseTexture.get(), osg::StateAttribute::ON);
+    _shadowCastingStateSet->setTextureAttribute(0, _fallbackBaseTexture.get(), osg::StateAttribute::ON);
     _shadowCastingStateSet->addUniform(new osg::Uniform("useDiffuseMapForShadowAlpha", true));
     _shadowCastingStateSet->addUniform(new osg::Uniform("alphaTestShadows", false));
     osg::ref_ptr<osg::Depth> depth = new osg::Depth;
@@ -3081,28 +3091,6 @@ bool MWShadowTechnique::adjustPerspectiveShadowMapCameraSettings(osgUtil::Render
     return true;
 }
 
-bool MWShadowTechnique::assignTexGenSettings(osgUtil::CullVisitor* cv, osg::Camera* camera, unsigned int textureUnit, osg::TexGen* texgen)
-{
-    OSG_INFO<<"assignTexGenSettings() textureUnit="<<textureUnit<<" texgen="<<texgen<<std::endl;
-
-    texgen->setMode(osg::TexGen::EYE_LINEAR);
-
-    // compute the matrix which takes a vertex from local coords into tex coords
-    // We actually use two matrices one used to define texgen
-    // and second that will be used as modelview when appling to OpenGL
-    texgen->setPlanesFromMatrix( camera->getProjectionMatrix() *
-                                 osg::Matrix::translate(1.0,1.0,1.0) *
-                                 osg::Matrix::scale(0.5,0.5,0.5) );
-
-    // Place texgen with modelview which removes big offsets (making it float friendly)
-    osg::ref_ptr<osg::RefMatrix> refMatrix =
-        new osg::RefMatrix( camera->getInverseViewMatrix() * (*(cv->getModelViewMatrix())) );
-
-    osgUtil::RenderStage* currentStage = cv->getCurrentRenderBin()->getStage();
-    currentStage->getPositionalStateContainer()->addPositionedTextureAttribute( textureUnit, refMatrix.get(), texgen );
-    return true;
-}
-
 void MWShadowTechnique::cullShadowReceivingScene(osgUtil::CullVisitor* cv) const
 {
     OSG_INFO<<"cullShadowReceivingScene()"<<std::endl;
@@ -3196,12 +3184,7 @@ osg::StateSet* MWShadowTechnique::prepareStateSetForRenderingShadow(ViewDependen
 
         OSG_INFO<<"   ShadowData for "<<sd._textureUnit<<std::endl;
 
-        stateset->setTextureAttributeAndModes(sd._textureUnit, sd._texture.get(), shadowMapModeValue);
+        stateset->setTextureAttribute(sd._textureUnit, sd._texture.get(), shadowMapModeValue);
-
-        stateset->setTextureMode(sd._textureUnit,GL_TEXTURE_GEN_S,osg::StateAttribute::ON);
-        stateset->setTextureMode(sd._textureUnit,GL_TEXTURE_GEN_T,osg::StateAttribute::ON);
-        stateset->setTextureMode(sd._textureUnit,GL_TEXTURE_GEN_R,osg::StateAttribute::ON);
-        stateset->setTextureMode(sd._textureUnit,GL_TEXTURE_GEN_Q,osg::StateAttribute::ON);
     }
 
     return stateset;
@@ -3304,7 +3287,7 @@ void SceneUtil::MWShadowTechnique::DebugHUD::draw(osg::ref_ptr<osg::Texture2D> t
         addAnotherShadowMap();
     
     osg::ref_ptr<osg::StateSet> stateSet = new osg::StateSet();
-    stateSet->setTextureAttributeAndModes(sDebugTextureUnit, texture, osg::StateAttribute::ON);
+    stateSet->setTextureAttribute(sDebugTextureUnit, texture, osg::StateAttribute::ON);
 
     auto frustumUniform = mFrustumUniforms[cv.getTraversalNumber() % 2][shadowMapNumber];
     frustumUniform->set(matrix);
@@ -3317,8 +3300,6 @@ void SceneUtil::MWShadowTechnique::DebugHUD::draw(osg::ref_ptr<osg::Texture2D> t
     mDebugCameras[shadowMapNumber]->accept(cv);
     cv.popStateSet();
     cv.setTraversalMask(traversalMask);
-
-    // cv.getState()->setCheckForGLErrors(osg::State::ONCE_PER_ATTRIBUTE);
 }
 
 void SceneUtil::MWShadowTechnique::DebugHUD::releaseGLObjects(osg::State* state) const

components/sceneutil/mwshadowtechnique.hpp

@@ -193,7 +193,6 @@ namespace SceneUtil {
 
             unsigned int                        _textureUnit;
             osg::ref_ptr<osg::Texture2D>        _texture;
-            osg::ref_ptr<osg::TexGen>           _texgen;
             osg::ref_ptr<osg::Camera>           _camera;
         };
 
@@ -241,8 +240,6 @@ namespace SceneUtil {
 
         void setCustomFrustumCallback(CustomFrustumCallback* cfc);
 
-        void assignTexGenSettings(osgUtil::CullVisitor& cv, ViewDependentData* vdd);
-
         virtual void createShaders();
 
         virtual bool selectActiveLights(osgUtil::CullVisitor* cv, ViewDependentData* vdd) const;
@@ -255,8 +252,6 @@ namespace SceneUtil {
 
         virtual bool adjustPerspectiveShadowMapCameraSettings(osgUtil::RenderStage* renderStage, Frustum& frustum, LightData& positionedLight, osg::Camera* camera, double viewNear, double viewFar);
 
-        virtual bool assignTexGenSettings(osgUtil::CullVisitor* cv, osg::Camera* camera, unsigned int textureUnit, osg::TexGen* texgen);
-
         virtual void cullShadowReceivingScene(osgUtil::CullVisitor* cv) const;
 
         virtual void cullShadowCastingScene(osgUtil::CullVisitor* cv, osg::Camera* camera) const;

components/sceneutil/shadow.cpp

@@ -13,7 +13,7 @@ namespace SceneUtil
 {
     using namespace osgShadow;
 
-    void ShadowManager::setupShadowSettings()
+    void ShadowManager::setupShadowSettings(Shader::ShaderManager& shaderManager)
     {
         mEnableShadows = Settings::Manager::getBool("enable shadows", "Shadows");
 
@@ -32,7 +32,8 @@ namespace SceneUtil
             = std::clamp(Settings::Manager::getInt("number of shadow maps", "Shadows"), 1, 8);
 
         mShadowSettings->setNumShadowMapsPerLight(numberOfShadowMapsPerLight);
-        mShadowSettings->setBaseShadowTextureUnit(8 - numberOfShadowMapsPerLight);
+        mShadowSettings->setBaseShadowTextureUnit(shaderManager.reserveGlobalTextureUnits(
+            Shader::ShaderManager::Slot::ShadowMaps, numberOfShadowMapsPerLight));
 
         const float maximumShadowMapDistance = Settings::Manager::getFloat("maximum shadow map distance", "Shadows");
         if (maximumShadowMapDistance > 0)
@@ -121,7 +122,7 @@ namespace SceneUtil
         mShadowedScene->setNodeMask(sceneRoot->getNodeMask());
 
         mShadowSettings = mShadowedScene->getShadowSettings();
-        setupShadowSettings();
+        setupShadowSettings(shaderManager);
 
         mShadowTechnique->setupCastingShader(shaderManager);
         mShadowTechnique->setWorldMask(worldMask);

components/sceneutil/shadow.hpp

@@ -29,7 +29,7 @@ namespace SceneUtil
             Shader::ShaderManager& shaderManager);
         ~ShadowManager();
 
-        void setupShadowSettings();
+        void setupShadowSettings(Shader::ShaderManager& shaderManager);
 
         Shader::ShaderManager::DefineMap getShadowDefines();
 

components/shader/shadermanager.cpp

@@ -681,31 +681,24 @@ namespace Shader
                 program->addShader(linkedShader);
     }
 
-    int ShaderManager::reserveGlobalTextureUnits(Slot slot)
+    int ShaderManager::reserveGlobalTextureUnits(Slot slot, int count)
     {
-        int unit = mReservedTextureUnitsBySlot[static_cast<int>(slot)];
+        // TODO: Reuse units when count increase forces reallocation
-        if (unit >= 0)
+        // TODO: Warn if trampling on the ~8 units needed by model textures
-            return unit;
+        auto unit = mReservedTextureUnitsBySlot[static_cast<int>(slot)];
+        if (unit.index >= 0 && unit.count >= count)
+            return unit.index;
 
-        {
+        if (getAvailableTextureUnits() < count + 1)
-            // Texture units from `8 - numberOfShadowMaps` to `8` are used for shadows, so we skip them here.
-            // TODO: Maybe instead of fixed texture units use `reserveGlobalTextureUnits` for shadows as well.
-            static const int numberOfShadowMaps = Settings::Manager::getBool("enable shadows", "Shadows")
-                ? std::clamp(Settings::Manager::getInt("number of shadow maps", "Shadows"), 1, 8)
-                : 0;
-            if (getAvailableTextureUnits() >= 8 && getAvailableTextureUnits() - 1 < 8)
-                mReservedTextureUnits = mMaxTextureUnits - (8 - numberOfShadowMaps);
-        }
-
-        if (getAvailableTextureUnits() < 2)
             throw std::runtime_error("Can't reserve texture unit; no available units");
-        mReservedTextureUnits++;
+        mReservedTextureUnits += count;
 
-        unit = mMaxTextureUnits - mReservedTextureUnits;
+        unit.index = mMaxTextureUnits - mReservedTextureUnits;
+        unit.count = count;
 
         mReservedTextureUnitsBySlot[static_cast<int>(slot)] = unit;
 
-        return unit;
+        return unit.index;
     }
 
     void ShaderManager::update(osgViewer::Viewer& viewer)

components/shader/shadermanager.hpp

@@ -80,9 +80,11 @@ namespace Shader
         {
             OpaqueDepthTexture,
             SkyTexture,
+            ShadowMaps,
+            SLOT_COUNT
         };
 
-        int reserveGlobalTextureUnits(Slot slot);
+        int reserveGlobalTextureUnits(Slot slot, int count = 1);
 
         void update(osgViewer::Viewer& viewer);
         void setHotReloadEnabled(bool value);
@@ -120,7 +122,12 @@ namespace Shader
         int mMaxTextureUnits = 0;
         int mReservedTextureUnits = 0;
         std::unique_ptr<HotReloadManager> mHotReloadManager;
-        std::array<int, 2> mReservedTextureUnitsBySlot = { -1, -1 };
+        struct ReservedTextureUnits
+        {
+            int index = -1;
+            int count = 0;
+        };
+        std::array<ReservedTextureUnits, static_cast<int>(Slot::SLOT_COUNT)> mReservedTextureUnitsBySlot = {};
     };
 
     bool parseForeachDirective(std::string& source, const std::string& templateName, size_t foundPos);

files/shaders/compatibility/shadows_vertex.glsl

@@ -2,6 +2,7 @@
 
 #if SHADOWS
     @foreach shadow_texture_unit_index @shadow_texture_unit_list
+        uniform mat4 shadowSpaceMatrix@shadow_texture_unit_index;
         uniform int shadowTextureUnit@shadow_texture_unit_index;
         varying vec4 shadowSpaceCoords@shadow_texture_unit_index;
 
@@ -19,33 +20,28 @@ void setupShadowCoords(vec4 viewPos, vec3 viewNormal)
 {
 #if SHADOWS
     // This matrix has the opposite handedness to the others used here, so multiplication must have the vector to the left. Alternatively it could be transposed after construction, but that's extra work for the GPU just to make the code look a tiny bit cleaner.
-    mat4 eyePlaneMat;
     vec4 shadowOffset;
     @foreach shadow_texture_unit_index @shadow_texture_unit_list
-        eyePlaneMat = mat4(gl_EyePlaneS[shadowTextureUnit@shadow_texture_unit_index], gl_EyePlaneT[shadowTextureUnit@shadow_texture_unit_index], gl_EyePlaneR[shadowTextureUnit@shadow_texture_unit_index], gl_EyePlaneQ[shadowTextureUnit@shadow_texture_unit_index]);
-
 #if @perspectiveShadowMaps
         shadowRegionCoords@shadow_texture_unit_index = validRegionMatrix@shadow_texture_unit_index * viewPos;
 #endif
 
 #if @disableNormalOffsetShadows
-        shadowSpaceCoords@shadow_texture_unit_index = viewPos * eyePlaneMat;
+        shadowSpaceCoords@shadow_texture_unit_index = shadowSpaceMatrix@shadow_texture_unit_index * viewPos;
 #else
         shadowOffset = vec4(viewNormal * @shadowNormalOffset, 0.0);
 
         if (onlyNormalOffsetUV)
         {
-            shadowSpaceCoords@shadow_texture_unit_index = viewPos * eyePlaneMat;
-
             vec4 lightSpaceXY = viewPos + shadowOffset;
-            lightSpaceXY = lightSpaceXY * eyePlaneMat;
+            lightSpaceXY = shadowSpaceMatrix@shadow_texture_unit_index * lightSpaceXY;
 
             shadowSpaceCoords@shadow_texture_unit_index.xy = lightSpaceXY.xy;
         }
         else
         {
             vec4 offsetViewPosition = viewPos + shadowOffset;
-            shadowSpaceCoords@shadow_texture_unit_index = offsetViewPosition * eyePlaneMat;
+            shadowSpaceCoords@shadow_texture_unit_index = shadowSpaceMatrix@shadow_texture_unit_index * offsetViewPosition;
         }
 #endif
     @endforeach