Add optional FBO ID parameter to render function.

This will allow external apps to pass in any custom FBO to render to. Defaults to 0, keeping previous behavior if not given.

Author: kblaschke

src/libprojectM/ProjectM.cpp

@@ -90,7 +90,7 @@ void ProjectM::ResetTextures()
     m_textureManager = std::make_unique<Renderer::TextureManager>(m_textureSearchPaths);
 }
 
-void ProjectM::RenderFrame()
+void ProjectM::RenderFrame(uint32_t targetFramebufferObject /*= 0*/)
 {
     // Don't render if window area is zero.
     if (m_windowWidth == 0 || m_windowHeight == 0)
@@ -166,8 +166,7 @@ void ProjectM::RenderFrame()
     // ToDo: Call the to-be-implemented render method in Renderer
     m_activePreset->RenderFrame(audioData, renderContext);
 
-    // ToDo: Allow external apps to provide a custom target framebuffer.
-    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
+    glBindFramebuffer(GL_DRAW_FRAMEBUFFER, static_cast<GLuint>(targetFramebufferObject));
 
     if (m_transition != nullptr && m_transitioningPreset != nullptr)
     {

src/libprojectM/ProjectM.hpp

@@ -101,7 +101,7 @@ class PROJECTM_EXPORT ProjectM
 
     void ResetTextures();
 
-    void RenderFrame();
+    void RenderFrame(uint32_t targetFramebufferObject = 0);
 
     void SetBeatSensitivity(float sensitivity);