Add API to set or retrieve values from user sprite expression variables

src/api/include/projectM-4/user_sprites.h

@@ -123,6 +123,28 @@ PROJECTM_EXPORT void projectm_sprite_set_max_sprites(projectm_handle instance,
  */
 PROJECTM_EXPORT uint32_t projectm_sprite_get_max_sprites(projectm_handle instance);
 
+/**
+ * @brief Retrieves the current value of an expression variable of a given sprite.
+ *
+ * @param instance The projectM instance handle.
+ * @param sprite_id The sprite ID returned by projectm_sprite_create() to retrieve the value for.
+ * @param var_name The variable name to retrieve the value for.
+ * @return The current value of the requested variable. Returns 0.0 if the variable is not defined.
+ * @since 4.2.0
+ */
+PROJECTM_EXPORT double projectm_sprite_get_var(projectm_handle instance, uint32_t sprite_id, const char* var_name);
+
+/**
+ * @brief Sets the value of the given variable for a single sprite instance.
+ *
+ * @param instance The projectM instance handle.
+ * @param sprite_id The sprite ID returned by projectm_sprite_create() to set the value for.
+ * @param var_name The variable to set a new value for.
+ * @param value The new value.
+ * @since 4.2.0
+ */
+PROJECTM_EXPORT void projectm_sprite_set_var(projectm_handle instance, uint32_t sprite_id, const char* var_name, double value);
+
 #ifdef __cplusplus
 } // extern "C"
 #endif

src/libprojectM/ProjectM.cpp

@@ -366,6 +366,16 @@ auto ProjectM::UserSpriteIdentifiers() const -> std::vector<uint32_t>
     return m_spriteManager->ActiveSpriteIdentifiers();
 }
 
+auto ProjectM::UserSpriteGetVariableValue(uint32_t spriteId, const std::string& variableName) const -> double
+{
+    return m_spriteManager->GetSpriteVariableValue(spriteId, variableName);
+}
+
+void ProjectM::UserSpriteSetVariableValue(uint32_t spriteId, const std::string& variableName, double value)
+{
+    m_spriteManager->SetSpriteVariableValue(spriteId, variableName, value);
+}
+
 void ProjectM::BurnInTexture(uint32_t openGlTextureId, int left, int top, int width, int height)
 {
     if (m_activePreset)

src/libprojectM/ProjectM.hpp

@@ -271,6 +271,22 @@ class PROJECTM_CXX_EXPORT ProjectM
      */
     auto UserSpriteIdentifiers() const -> std::vector<uint32_t>;
 
+    /**
+     * @brief Returns the current value of a variable in a user sprite's expression code.
+     * @param spriteId The sprite ID to retrieve the value for.
+     * @param variableName The variable to retrieve the value for.
+     * @return The value of the requested variable and sprite.
+     */
+    auto UserSpriteGetVariableValue(uint32_t spriteId, const std::string& variableName) const -> double;
+
+    /**
+     * @brief Set the value of a variable in a user sprite's expression code.
+     * @param spriteId The sprite ID to set the value for.
+     * @param variableName The variable to set the value for.
+     * @param value The new value.
+     */
+    void UserSpriteSetVariableValue(uint32_t spriteId, const std::string& variableName, double value);
+
     /**
      * @brief Draws the given texture on the active preset's main texture to get a "burn-in" effect.
      * @param openGlTextureId The OpenGL texture to draw onto the active preset(s).

src/libprojectM/ProjectMCWrapper.cpp

@@ -538,6 +538,19 @@ uint32_t projectm_sprite_get_max_sprites(projectm_handle instance)
     return projectMInstance->UserSpriteLimit();
 }
 
+double projectm_sprite_get_var(projectm_handle instance, uint32_t sprite_id, const char* var_name)
+{
+    auto* projectMInstance = handle_to_instance(instance);
+
+    return projectMInstance->UserSpriteGetVariableValue(sprite_id, var_name);
+}
+
+void projectm_sprite_set_var(projectm_handle instance, uint32_t sprite_id, const char* var_name, double value)
+{
+    auto* projectMInstance = handle_to_instance(instance);
+
+    projectMInstance->UserSpriteSetVariableValue(sprite_id, var_name, value);
+}
 void projectm_set_log_callback(projectm_log_callback callback, bool current_thread_only, void* user_data)
 {
     if (current_thread_only)

src/libprojectM/UserSprites/MilkdropSprite.cpp

@@ -290,6 +290,26 @@ auto MilkdropSprite::Done() const -> bool
     return m_spriteDone;
 }
 
+auto MilkdropSprite::GetVariableValue(const std::string& variableName) const -> double
+{
+    PRJM_EVAL_F const* var = projectm_eval_context_register_variable(m_codeContext.spriteCodeContext, variableName.c_str());
+    if (var != nullptr)
+    {
+        return *var;
+    }
+
+    return 0.0;
+}
+
+void MilkdropSprite::SetVariableValue(const std::string& variableName, double value)
+{
+    PRJM_EVAL_F * var = projectm_eval_context_register_variable(m_codeContext.spriteCodeContext, variableName.c_str());
+    if (var != nullptr)
+    {
+        *var = value;
+    }
+}
+
 MilkdropSprite::CodeContext::CodeContext()
     : spriteCodeContext(projectm_eval_context_create(nullptr, nullptr))
 {

src/libprojectM/UserSprites/MilkdropSprite.hpp

@@ -27,6 +27,10 @@ class MilkdropSprite : public Sprite
 
     auto Done() const -> bool override;
 
+    auto GetVariableValue(const std::string& variableName) const -> double override;
+
+    void SetVariableValue(const std::string& variableName, double value) override;
+
 private:
     /**
      * @brief Context for the init and per-frame code.
@@ -43,7 +47,7 @@ class MilkdropSprite : public Sprite
 
         /**
          * @brief Compiles and runs the init code of the sprite once, if any.
-         * Also sets up a the default values of the output variables.
+         * Also sets up the default values of the output variables.
          * @param initCode The initialization code.
          */
         void RunInitCode(const std::string& initCode, const Renderer::RenderContext& renderContext);
@@ -74,15 +78,15 @@ class MilkdropSprite : public Sprite
         // Output variables
         PRJM_EVAL_F* done{};      //!< If this becomes non-zero, the sprite is deleted. Default: 0.0
         PRJM_EVAL_F* burn{};      //!< If non-zero, the sprite will be "burned" into currently rendered presets when done is also true, effectively "dissolving" the sprite in the preset. Default: 1.0
-        PRJM_EVAL_F* x{};         //!< Sprite x position (position of the image center). Range from -1000 to 1000. Default: 0.5
-        PRJM_EVAL_F* y{};         //!< Sprite y position (position of the image center). Range from -1000 to 1000. Default: 0.5
-        PRJM_EVAL_F* sx{};        //!< Sprite x scaling factor. Range from -1000 to 1000. Default: 1.0
-        PRJM_EVAL_F* sy{};        //!< Sprite y scaling factor. Range from -1000 to 1000. Default: 1.0
+        PRJM_EVAL_F* x{};         //!< Sprite X position (position of the image center). Range from -1000 to 1000. Default: 0.5
+        PRJM_EVAL_F* y{};         //!< Sprite Y position (position of the image center). Range from -1000 to 1000. Default: 0.5
+        PRJM_EVAL_F* sx{};        //!< Sprite X scaling factor. Range from -1000 to 1000. Default: 1.0
+        PRJM_EVAL_F* sy{};        //!< Sprite Y scaling factor. Range from -1000 to 1000. Default: 1.0
         PRJM_EVAL_F* rot{};       //!< Sprite rotation in radians (2*PI equals one full rotation). Default: 0.0
-        PRJM_EVAL_F* flipx{};     //!< If flag is non-zero, the sprite is flipped on the x axis. Default: 0.0
-        PRJM_EVAL_F* flipy{};     //!< If flag is non-zero, the sprite is flipped on the y axis. Default: 0.0
-        PRJM_EVAL_F* repeatx{};   //!< Repeat count of the image on the sprite quad on the x axis. Fractional values allowed. Range from 0.01 to 100.0. Default: 1.0
-        PRJM_EVAL_F* repeaty{};   //!< Repeat count of the image on the sprite quad on the y axis. Fractional values allowed. Range from 0.01 to 100.0. Default: 1.0
+        PRJM_EVAL_F* flipx{};     //!< If flag is non-zero, the sprite is flipped on the X axis. Default: 0.0
+        PRJM_EVAL_F* flipy{};     //!< If flag is non-zero, the sprite is flipped on the Y axis. Default: 0.0
+        PRJM_EVAL_F* repeatx{};   //!< Repeat count of the image on the sprite quad on the X axis. Fractional values allowed. Range from 0.01 to 100.0. Default: 1.0
+        PRJM_EVAL_F* repeaty{};   //!< Repeat count of the image on the sprite quad on the Y axis. Fractional values allowed. Range from 0.01 to 100.0. Default: 1.0
         PRJM_EVAL_F* blendmode{}; //!< Image blending mode. 0 = Alpha blending (default), 1 = Decal mode (no transparency), 2 = Additive blending, 3 = Source color blending, 4 = Color key blending. Default: 0
         PRJM_EVAL_F* r{};         //!< Modulation color used in some blending modes. Default: 1.0
         PRJM_EVAL_F* g{};         //!< Modulation color used in some blending modes. Default: 1.0

src/libprojectM/UserSprites/Sprite.hpp

@@ -47,6 +47,20 @@ class Sprite
      * @return true if the sprite should be deleted, false if not.
      */
     virtual auto Done() const -> bool = 0;
+
+    /**
+     * @brief Returns the current value of a variable in the sprite's expression code.
+     * @param variableName The variable to retrieve the value for.
+     * @return The value of the requested variable and sprite.
+     */
+    virtual auto GetVariableValue(const std::string& variableName) const -> double = 0;
+
+    /**
+     * @brief Set the value of a variable in the sprite's expression code.
+     * @param variableName The variable to set the value for.
+     * @param value The new value.
+     */
+    virtual void SetVariableValue(const std::string& variableName, double value) = 0;
 };
 
 } // namespace UserSprites

src/libprojectM/UserSprites/SpriteManager.cpp

@@ -65,7 +65,8 @@ void SpriteManager::Draw(const Audio::FrameAudioData& audioData,
 {
     std::vector<SpriteIdentifier> toDestroy;
 
-    for (auto& idAndSprite : m_sprites) {
+    for (auto& idAndSprite : m_sprites)
+    {
         idAndSprite.second->Draw(audioData, renderContext, outputFramebufferObject, presets);
 
         if (idAndSprite.second->Done())
@@ -132,6 +133,40 @@ auto SpriteManager::SpriteSlots() const -> uint32_t
     return m_spriteSlots;
 }
 
+auto SpriteManager::GetSpriteVariableValue(SpriteIdentifier spriteIdentifier, const std::string& variableName) const -> double
+{
+    if (m_spriteIdentifiers.find(spriteIdentifier) == m_spriteIdentifiers.end())
+    {
+        return 0.0;
+    }
+
+    for (const auto& idAndSprite : m_sprites)
+    {
+        if (idAndSprite.first == spriteIdentifier)
+        {
+            return idAndSprite.second->GetVariableValue(variableName);
+        }
+    }
+
+    return 0.0;
+}
+
+void SpriteManager::SetSpriteVariableValue(SpriteIdentifier spriteIdentifier, const std::string& variableName, double value)
+{
+    if (m_spriteIdentifiers.find(spriteIdentifier) == m_spriteIdentifiers.end())
+    {
+        return;
+    }
+
+    for (const auto& idAndSprite : m_sprites)
+    {
+        if (idAndSprite.first == spriteIdentifier)
+        {
+            idAndSprite.second->SetVariableValue(variableName, value);
+        }
+    }
+}
+
 auto SpriteManager::GetLowestFreeIdentifier() -> SpriteIdentifier
 {
     SpriteIdentifier lowestId = 0;

src/libprojectM/UserSprites/SpriteManager.hpp

@@ -82,6 +82,22 @@ class SpriteManager
      */
     auto SpriteSlots() const -> uint32_t;
 
+    /**
+     * @brief Returns the current value of a variable in a user sprite's expression code.
+     * @param spriteIdentifier The sprite ID to retrieve the value for.
+     * @param variableName The variable to retrieve the value for.
+     * @return The value of the requested variable and sprite.
+     */
+    auto GetSpriteVariableValue(SpriteIdentifier spriteIdentifier, const std::string& variableName) const -> double;
+
+    /**
+     * @brief Set the value of a variable in a user sprite's expression code.
+     * @param spriteIdentifier The sprite ID to set the value for.
+     * @param variableName The variable to set the value for.
+     * @param value The new value.
+     */
+    void SetSpriteVariableValue(SpriteIdentifier spriteIdentifier, const std::string& variableName, double value);
+
 private:
     using SpriteIdPair = std::pair<SpriteIdentifier, Sprite::Ptr>;