Add the ability to specify a custom shader for the RenderableGalaxy class

modules/galaxy/rendering/galaxyraycaster.cpp

@@ -43,10 +43,12 @@ namespace {
 
 namespace openspace {
 
-GalaxyRaycaster::GalaxyRaycaster(ghoul::opengl::Texture& texture)
+GalaxyRaycaster::GalaxyRaycaster(ghoul::opengl::Texture& texture,
+                                 std::optional<std::filesystem::path> raycastingShader)
     : _boundingBox(glm::vec3(1.f))
     , _texture(texture)
     , _textureUnit(nullptr)
+    , _raycastingShader(raycastingShader.value_or(GlslRaycastPath))
 {}
 
 void GalaxyRaycaster::initialize() {
@@ -149,7 +151,7 @@ std::string GalaxyRaycaster::boundsFragmentShaderPath() const {
 }
 
 std::string GalaxyRaycaster::raycasterPath() const {
-    return std::string(GlslRaycastPath);
+    return _raycastingShader.string();
 }
 
 std::string GalaxyRaycaster::helperPath() const {

modules/galaxy/rendering/galaxyraycaster.h

@@ -45,7 +45,8 @@ struct RaycastData;
 
 class GalaxyRaycaster : public VolumeRaycaster {
 public:
-    GalaxyRaycaster(ghoul::opengl::Texture& texture);
+    GalaxyRaycaster(ghoul::opengl::Texture& texture,
+        std::optional<std::filesystem::path> raycastingShader = std::nullopt);
     ~GalaxyRaycaster() override = default;
 
     void initialize();
@@ -87,6 +88,7 @@ private:
     float _emissionMultiply = 0.f;
     ghoul::opengl::Texture& _texture;
     std::unique_ptr<ghoul::opengl::TextureUnit> _textureUnit;
+    std::filesystem::path _raycastingShader;
 
 }; // GalaxyRaycaster
 

modules/galaxy/rendering/renderablegalaxy.cpp

@@ -175,6 +175,10 @@ namespace {
         // [[codegen::verbatim(EmissionMultiplyInfo.description)]]
         std::optional<float> emissionMultiply;
 
+        // If this value is specified, the default raycasting shader is overwritten and
+        // the shader found at the provided location is used instead
+        std::optional<std::filesystem::path> raycastingShader;
+
         enum class [[codegen::map(StarRenderingMethod)]] StarRenderingMethod {
             Points,
             Billboards
@@ -285,6 +289,7 @@ RenderableGalaxy::RenderableGalaxy(const ghoul::Dictionary& dictionary)
     _stepSize = p.stepSizeInfo.value_or(_stepSize);
     _absorptionMultiply = p.absorptionMultiply.value_or(_absorptionMultiply);
     _emissionMultiply = p.emissionMultiply.value_or(_emissionMultiply);
+    _raycastingShader = p.raycastingShader.value_or(_raycastingShader);
 
     _starRenderingMethod.addOptions({
         { StarRenderingMethod::Points, "Points" },
@@ -417,7 +422,12 @@ void RenderableGalaxy::initializeGL() {
     _texture->setDimensions(_volume->dimensions());
     _texture->uploadTexture();
 
-    _raycaster = std::make_unique<GalaxyRaycaster>(*_texture);
+    if (_raycastingShader.empty()) {
+        _raycaster = std::make_unique<GalaxyRaycaster>(*_texture);
+    }
+    else {
+        _raycaster = std::make_unique<GalaxyRaycaster>(*_texture, _raycastingShader);
+    }
     _raycaster->initialize();
 
     // We no longer need the data

modules/galaxy/rendering/renderablegalaxy.h

@@ -88,6 +88,7 @@ private:
     glm::ivec3 _volumeDimensions = glm::ivec3(0);
     std::string _pointsFilename;
     std::string _pointSpreadFunctionTexturePath;
+    std::filesystem::path _raycastingShader;
 
     std::unique_ptr<GalaxyRaycaster> _raycaster;
     std::unique_ptr<volume::RawVolume<glm::tvec4<GLubyte>>> _volume;