From 301222ea27877db437a9c3dc0e2cbc1d0abad7c1 Mon Sep 17 00:00:00 2001
From: Kai Blaschke <kai.blaschke@kb-dev.net>
Date: Fri, 12 Jul 2024 13:29:19 +0200
Subject: [PATCH] Properly check for uninitialized texture in CopyTexture
 class.

Before rendering the first frame, there is no output texture present in a preset, so we can't copy anything and should just skip that step.
---
 src/libprojectM/Renderer/CopyTexture.cpp |  5 ++++-
 src/libprojectM/Renderer/Texture.cpp     | 11 ++++++++---
 src/libprojectM/Renderer/Texture.hpp     | 11 ++++++++++-
 3 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/libprojectM/Renderer/CopyTexture.cpp b/src/libprojectM/Renderer/CopyTexture.cpp
index 8e8ce336a..6a0c58605 100644
--- a/src/libprojectM/Renderer/CopyTexture.cpp
+++ b/src/libprojectM/Renderer/CopyTexture.cpp
@@ -157,7 +157,10 @@ void CopyTexture::Draw(const std::shared_ptr<class Texture>& originalTexture, co
 void CopyTexture::Draw(const std::shared_ptr<class Texture>& originalTexture, Framebuffer& framebuffer, int framebufferIndex,
                        bool flipVertical, bool flipHorizontal)
 {
-    if (originalTexture == nullptr || framebuffer.GetColorAttachmentTexture(framebufferIndex, 0) == nullptr)
+    if (originalTexture == nullptr
+        || originalTexture->Empty()
+        || framebuffer.GetColorAttachmentTexture(framebufferIndex, 0) == nullptr
+        || framebuffer.GetColorAttachmentTexture(framebufferIndex, 0)->Empty())
     {
         return;
     }
diff --git a/src/libprojectM/Renderer/Texture.cpp b/src/libprojectM/Renderer/Texture.cpp
index 47fb59b30..db0effa74 100644
--- a/src/libprojectM/Renderer/Texture.cpp
+++ b/src/libprojectM/Renderer/Texture.cpp
@@ -15,7 +15,7 @@ Texture::Texture(std::string name, const int width, const int height, const bool
     , m_format(GL_RGB)
     , m_type(GL_UNSIGNED_BYTE)
 {
-    CreateEmptyTexture();
+    CreateNewTexture();
 }
 
 Texture::Texture(std::string name, int width, int height,
@@ -29,7 +29,7 @@ Texture::Texture(std::string name, int width, int height,
     , m_format(format)
     , m_type(type)
 {
-    CreateEmptyTexture();
+    CreateNewTexture();
 }
 
 Texture::Texture(std::string name, const GLuint texID, const GLenum target,
@@ -99,7 +99,12 @@ auto Texture::IsUserTexture() const -> bool
     return m_isUserTexture;
 }
 
-void Texture::CreateEmptyTexture()
+auto Texture::Empty() const -> bool
+{
+    return m_textureId == 0;
+}
+
+void Texture::CreateNewTexture()
 {
     glGenTextures(1, &m_textureId);
     glBindTexture(m_target, m_textureId);
diff --git a/src/libprojectM/Renderer/Texture.hpp b/src/libprojectM/Renderer/Texture.hpp
index 4577b1712..75fce1164 100644
--- a/src/libprojectM/Renderer/Texture.hpp
+++ b/src/libprojectM/Renderer/Texture.hpp
@@ -115,8 +115,17 @@ class Texture
      */
     auto IsUserTexture() const -> bool;
 
+    /**
+     * @brief Returns true if the texture is empty/unallocated.
+     * @return true if the texture is not yet allocated (e.g. the ID 0), false if the object contains a valid texture.
+     */
+    auto Empty() const -> bool;
+
 private:
-    void CreateEmptyTexture();
+    /**
+     * @brief Creates a new, blank texture with the given size.
+     */
+    void CreateNewTexture();
 
     GLuint m_textureId{0};    //!< The OpenGL texture name/ID.
     GLenum m_target{GL_NONE}; //!< The OpenGL texture target, e.g. GL_TEXTURE_2D.