Use MSAA for shadowmap

src/graphics/glwrap.cpp

@@ -162,10 +162,10 @@ unsigned GPUTimer::elapsedTimeus()
     return result / 1000;
 }
 
-FrameBuffer::FrameBuffer() {}
+FrameBuffer::FrameBuffer() : layerfbo(0) {}
 
 FrameBuffer::FrameBuffer(const std::vector<GLuint> &RTTs, size_t w, size_t h, bool layered) :
-    RenderTargets(RTTs), DepthTexture(0), width(w), height(h)
+RenderTargets(RTTs), DepthTexture(0), width(w), height(h), layerfbo(0)
 {
     glGenFramebuffers(1, &fbo);
     glBindFramebuffer(GL_FRAMEBUFFER, fbo);
@@ -184,7 +184,7 @@ FrameBuffer::FrameBuffer(const std::vector<GLuint> &RTTs, size_t w, size_t h, bo
 }
 
 FrameBuffer::FrameBuffer(const std::vector<GLuint> &RTTs, GLuint DS, size_t w, size_t h, bool layered) :
-    RenderTargets(RTTs), DepthTexture(DS), width(w), height(h)
+RenderTargets(RTTs), DepthTexture(DS), width(w), height(h), layerfbo(0)
 {
     glGenFramebuffers(1, &fbo);
     glBindFramebuffer(GL_FRAMEBUFFER, fbo);
@@ -202,11 +202,16 @@ FrameBuffer::FrameBuffer(const std::vector<GLuint> &RTTs, GLuint DS, size_t w, s
     }
     GLenum result = glCheckFramebufferStatus(GL_FRAMEBUFFER);
     assert(result == GL_FRAMEBUFFER_COMPLETE_EXT);
+
+    if (layered)
+        glGenFramebuffers(1, &layerfbo);
 }
 
 FrameBuffer::~FrameBuffer()
 {
     glDeleteFramebuffers(1, &fbo);
+    if (layerfbo)
+        glDeleteFramebuffers(1, &layerfbo);
 }
 
 void FrameBuffer::Bind()
@@ -227,6 +232,20 @@ void FrameBuffer::Blit(const FrameBuffer &Src, FrameBuffer &Dst, GLbitfield mask
     glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
 }
 
+void FrameBuffer::BlitLayer(const FrameBuffer &Src, FrameBuffer &Dst, unsigned layer, GLbitfield mask, GLenum filter)
+{
+    glBindFramebuffer(GL_READ_FRAMEBUFFER, Src.layerfbo);
+    glFramebufferTextureLayer(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, Src.RenderTargets[0], 0, layer);
+    glFramebufferTextureLayer(GL_READ_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, Src.DepthTexture, 0, layer);
+    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, Dst.layerfbo);
+    glFramebufferTextureLayer(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, Dst.RenderTargets[0], 0, layer);
+    glFramebufferTextureLayer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, Dst.DepthTexture, 0, layer);
+    glBlitFramebuffer(0, 0, (int)Src.width, (int)Src.height, 0, 0,
+        (int)Dst.width, (int)Dst.height, mask, filter);
+    glBindFramebuffer(GL_READ_FRAMEBUFFER, 0);
+    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+}
+
 void FrameBuffer::BlitToDefault(size_t x0, size_t y0, size_t x1, size_t y1)
 {
     glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo);

src/graphics/glwrap.hpp

@@ -43,7 +43,7 @@ public:
 class FrameBuffer
 {
 private:
-    GLuint fbo;
+    GLuint fbo, layerfbo;
     std::vector<GLuint> RenderTargets;
     GLuint DepthTexture;
     size_t width, height;
@@ -59,6 +59,7 @@ public:
     size_t getHeight() const { return height; }
     static void Blit(const FrameBuffer &Src, FrameBuffer &Dst, GLbitfield mask = GL_COLOR_BUFFER_BIT, GLenum filter = GL_NEAREST);
     void BlitToDefault(size_t, size_t, size_t, size_t);
+    static void BlitLayer(const FrameBuffer &Src, FrameBuffer &Dst, unsigned layer, GLbitfield mask, GLenum filter);
 };
 
 class VertexUtils

src/graphics/render_geometry.cpp

@@ -978,12 +978,15 @@ void IrrDriver::renderShadows()
     glDepthMask(GL_TRUE);
     glEnable(GL_DEPTH_TEST);
     glDisable(GL_BLEND);
-    m_rtts->getShadowFBO().Bind();
+    m_rtts->getShadowMSAAFBO().Bind();
 
     glClearColor(1., 1., 1., 1.);
     glClear(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
     glClearColor(0., 0., 0., 0.);
 
+
+    glEnable(GL_MULTISAMPLE);
+
     for (unsigned cascade = 0; cascade < 4; cascade++)
     {
         ScopedGPUTimer Timer(getGPUTimer(Q_SHADOWS_CASCADE0 + cascade));
@@ -1020,6 +1023,10 @@ void IrrDriver::renderShadows()
         }
     }
 
+    glDisable(GL_MULTISAMPLE);
+
+    for (unsigned i = 0; i < 4; i++)
+        FrameBuffer::BlitLayer(m_rtts->getShadowMSAAFBO(), m_rtts->getShadowFBO(), i, GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT, GL_NEAREST);
     glBindTexture(GL_TEXTURE_2D_ARRAY, m_rtts->getShadowFBO().getRTT()[0]);
     glGenerateMipmap(GL_TEXTURE_2D_ARRAY);
 }

src/graphics/rtts.cpp

@@ -229,6 +229,17 @@ RTT::RTT(size_t width, size_t height)
         somevector.clear();
         somevector.push_back(shadowColorTex);
         m_shadow_FBO = new FrameBuffer(somevector, shadowDepthTex, 1024, 1024, true);
+
+        glGenTextures(1, &shadowColorMSAATex);
+        glBindTexture(GL_TEXTURE_2D_MULTISAMPLE_ARRAY, shadowColorMSAATex);
+        glTexStorage3DMultisample(GL_TEXTURE_2D_MULTISAMPLE_ARRAY, 8, GL_R32F, 1024, 1024, 4, true);
+        glGenTextures(1, &shadowDepthMSAATex);
+        glBindTexture(GL_TEXTURE_2D_MULTISAMPLE_ARRAY, shadowDepthMSAATex);
+        glTexStorage3DMultisample(GL_TEXTURE_2D_MULTISAMPLE_ARRAY, 8, GL_DEPTH_COMPONENT32, 1024, 1024, 4, true);
+
+        somevector.clear();
+        somevector.push_back(shadowColorMSAATex);
+        m_shadowMSAA_FBO = new FrameBuffer(somevector, shadowDepthMSAATex, 1024, 1024, true);
     }
 
     if (UserConfigParams::m_gi)

src/graphics/rtts.hpp

@@ -42,6 +42,7 @@ public:
     ~RTT();
 
     FrameBuffer &getShadowFBO() { return *m_shadow_FBO; }
+    FrameBuffer &getShadowMSAAFBO() { return *m_shadowMSAA_FBO; }
     FrameBuffer &getRH() { return *m_RH_FBO; }
     FrameBuffer &getRSM() { return *m_RSM; }
 
@@ -60,9 +61,10 @@ private:
     int m_height;
 
     unsigned shadowColorTex, shadowNormalTex, shadowDepthTex;
+    unsigned shadowColorMSAATex, shadowDepthMSAATex;
     unsigned RSM_Color, RSM_Normal, RSM_Depth;
     unsigned RH_Red, RH_Green, RH_Blue;
-    FrameBuffer* m_shadow_FBO, *m_RSM, *m_RH_FBO;
+    FrameBuffer* m_shadow_FBO, *m_shadowMSAA_FBO, *m_RSM, *m_RH_FBO;
 
     LEAK_CHECK();
 };