Take back manual depth test for the two pass model rendering

include/openspace/rendering/framebufferrenderer.h

@@ -59,7 +59,9 @@ class FramebufferRenderer final : public RaycasterListener, public Deferredcaste
 public:
     virtual ~FramebufferRenderer() override = default;
 
-    // Functions to access and reuse some of the existing textures
+    //============================//
+    //=====  Reuse textures  =====//
+    //============================//
     /**
      * Gives access to the currently NOT used pingPongTexture. This texture is available
      * for all RenderBins. However, it cannot be used at the same time as the Deferred
@@ -100,6 +102,46 @@ public:
      */
     GLuint additionalDepthTexture();
 
+    //=============================//
+    //=====  Access G-buffer  =====//
+    //=============================//
+    // Functions to access the G-buffer textures
+    /**
+     * Gives access to the color texture of the G-buffer. NOTE: This texture is used for
+     * the majority of rendering the scene and might be already in use. Use CAUTION when
+     * using this function. The size of the texture is the resolution of the viewport.
+     *
+     * \return GLuint identifier of the color texture of the G-buffer
+     */
+    GLuint gBufferColorTexture();
+
+    /**
+     * Gives access to the position texture of the G-buffer. NOTE: This texture is used for
+     * the majority of rendering the scene and might be already in use. Use CAUTION when
+     * using this function. The size of the texture is the resolution of the viewport.
+     *
+     * \return GLuint identifier of the position texture of the G-buffer
+     */
+    GLuint gBufferPositionTexture();
+
+    /**
+     * Gives access to the normal texture of the G-buffer. NOTE: This texture is used for
+     * the majority of rendering the scene and might be already in use. Use CAUTION when
+     * using this function. The size of the texture is the resolution of the viewport.
+     *
+     * \return GLuint identifier of the normal texture of the G-buffer
+     */
+    GLuint gBufferNormalTexture();
+
+    /**
+     * Gives access to the depth texture of the G-buffer. NOTE: This texture is used for
+     * the majority of rendering the scene and might be already in use. Use CAUTION when
+     * using this function. The size of the texture is the resolution of the viewport.
+     *
+     * \return GLuint identifier of the depth texture of the G-buffer
+     */
+    GLuint gBufferDepthTexture();
+
     void initialize();
     void deinitialize();
 

modules/base/rendering/renderablemodel.cpp

@@ -71,11 +71,11 @@ namespace {
        GL_COLOR_ATTACHMENT2,
     };
 
-    constexpr std::array<const char*, 10> UniformNames = {
+    constexpr std::array<const char*, 12> UniformNames = {
         "nLightSources", "lightDirectionsViewSpace", "lightIntensities",
         "modelViewTransform", "normalTransform", "projectionTransform",
         "performShading", "ambientIntensity", "diffuseIntensity",
-        "specularIntensity"
+        "specularIntensity", "performManualDepthTest", "gBufferDepthTexture"
     };
 
     constexpr std::array<const char*, 5> UniformOpacityNames = {
@@ -781,6 +781,12 @@ void RenderableModel::render(const RenderData& data, RendererTasks&) {
     }
 
     if (!shouldRenderTwise) {
+        // Reset manual depth test
+        _program->setUniform(
+            _uniformCache.performManualDepthTest,
+            false
+        );
+
         _geometry->render(*_program);
     }
     else {
@@ -806,6 +812,26 @@ void RenderableModel::render(const RenderData& data, RendererTasks&) {
         glClearBufferfv(GL_COLOR, 1, glm::value_ptr(glm::vec4(0.f, 0.f, 0.f, 0.f)));
         glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
+        // Use a manuel depth test to make the models aware of the rest of the envierment
+        _program->setUniform(
+            _uniformCache.performManualDepthTest,
+            true
+        );
+
+        // Bind the G-buffer depth texture for a manual depth test towards the rest
+        // of the scene
+        ghoul::opengl::TextureUnit gBufferDepthTextureUnit;
+        gBufferDepthTextureUnit.activate();
+        glBindTexture(
+            GL_TEXTURE_2D,
+            global::renderEngine->renderer()->gBufferDepthTexture()
+        );
+        _program->setUniform(
+            _uniformCache.gBufferDepthTexture,
+            gBufferDepthTextureUnit
+        );
+
+
         // Render Pass 1
         // Render all parts of the model into the new framebuffer without opacity
         _geometry->render(*_program);

modules/base/rendering/renderablemodel.h

@@ -106,7 +106,7 @@ private:
     UniformCache(nLightSources, lightDirectionsViewSpace, lightIntensities,
         modelViewTransform, normalTransform, projectionTransform,
         performShading, ambientIntensity, diffuseIntensity,
-        specularIntensity) _uniformCache;
+        specularIntensity, performManualDepthTest, gBufferDepthTexture) _uniformCache;
 
     std::vector<std::unique_ptr<LightSource>> _lightSources;
 

modules/base/shaders/model_fs.glsl

@@ -48,6 +48,8 @@ uniform vec4 color_specular;
 uniform int nLightSources;
 uniform vec3 lightDirectionsViewSpace[8];
 uniform float lightIntensities[8];
+uniform bool performManualDepthTest = false;
+uniform sampler2D gBufferDepthTexture;
 
 Fragment getFragment() {
   Fragment frag;
@@ -56,6 +58,17 @@ Fragment getFragment() {
   frag.gNormal = vec4(vs_normalViewSpace, 0.0);
   frag.disableLDR2HDR = true;
 
+  if (performManualDepthTest) {
+    // Manual depth test
+    float gBufferDepth =
+      denormalizeFloat(texture(gBufferDepthTexture, viewportPixelCoord).x);
+    if (vs_screenSpaceDepth > gBufferDepth) {
+      frag.color = vec4(0.f);
+      frag.depth = gBufferDepth;
+      return frag;
+    }
+  }
+
   // Render invisible mesh with flashy procedural material
   if (use_forced_color) {
     vec3 adjustedPos = floor(vs_positionCameraSpace.xyz * 3.0);

src/rendering/framebufferrenderer.cpp

@@ -87,9 +87,9 @@ namespace {
 
 namespace openspace {
 
-//=====================================//
-//=====  Reuse NOT used textures  =====//
-//=====================================//
+//============================//
+//=====  Reuse textures  =====//
+//============================//
 // Gives access to the currently NOT used pingPongTexture
 GLuint FramebufferRenderer::additionalColorTexture1() {
     int unusedPingPongIndex = _pingPongIndex == 0 ? 1 : 0;
@@ -111,6 +111,29 @@ GLuint FramebufferRenderer::additionalDepthTexture() {
     return _exitDepthTexture;
 }
 
+//=============================//
+//=====  Access G-buffer  =====//
+//=============================//
+// / Gives access to the color texture of the G-buffer
+GLuint FramebufferRenderer::gBufferColorTexture() {
+    return _gBuffers.colorTexture;
+}
+
+//  Gives access to the position texture of the G-buffer
+GLuint FramebufferRenderer::gBufferPositionTexture() {
+    return _gBuffers.positionTexture;
+}
+
+//  Gives access to the normal texture of the G-buffer
+GLuint FramebufferRenderer::gBufferNormalTexture() {
+    return _gBuffers.normalTexture;
+}
+
+//  Gives access to the depth texture of the G-buffer
+GLuint FramebufferRenderer::gBufferDepthTexture() {
+    return _gBuffers.depthTexture;
+}
+
 void FramebufferRenderer::initialize() {
     ZoneScoped
     TracyGpuZone("Rendering initialize");