From c0bf766adfb17da8723aa049070e74a2a4cdd985 Mon Sep 17 00:00:00 2001
From: Sergii Liebodkin <s.lebedkin@gmail.com>
Date: Sun, 20 Jul 2025 19:07:37 +0300
Subject: [PATCH] gl_engine: fix FBO validation At the moment, we use the value
 GL_INVALID_VALUE to mark an invalid handle for FBO, which is not correct. It
 is more correct to use the value 0, which signals that the buffer was not
 created. Canvas initialization processes have also been adjusted

---
 src/renderer/gl_engine/tvgGlRenderTarget.cpp | 8 ++++++--
 src/renderer/gl_engine/tvgGlRenderTarget.h   | 4 ++--
 src/renderer/gl_engine/tvgGlRenderer.cpp     | 2 +-
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/renderer/gl_engine/tvgGlRenderTarget.cpp b/src/renderer/gl_engine/tvgGlRenderTarget.cpp
index d4dbf5de..7226543e 100644
--- a/src/renderer/gl_engine/tvgGlRenderTarget.cpp
+++ b/src/renderer/gl_engine/tvgGlRenderTarget.cpp
@@ -31,7 +31,7 @@ GlRenderTarget::~GlRenderTarget()
 
 void GlRenderTarget::init(uint32_t width, uint32_t height, GLint resolveId)
 {
-    if (mFbo != GL_INVALID_VALUE || width == 0 || height == 0) return;
+    if (mFbo != 0 || width == 0 || height == 0) return;
     mWidth = width;
     mHeight = height;
 
@@ -84,7 +84,11 @@ void GlRenderTarget::reset()
     GL_CHECK(glDeleteRenderbuffers(1, &mDepthStencilBuffer));
     GL_CHECK(glDeleteFramebuffers(1, &mResolveFbo));
     GL_CHECK(glDeleteTextures(1, &mColorTex));
-    mFbo = GL_INVALID_VALUE;
+    mFbo = 0;
+    mColorBuffer = 0;
+    mDepthStencilBuffer = 0;
+    mResolveFbo = 0;
+    mColorTex = 0;
 }
 
 GlRenderTargetPool::GlRenderTargetPool(uint32_t maxWidth, uint32_t maxHeight): mMaxWidth(maxWidth), mMaxHeight(maxHeight), mPool() {}
diff --git a/src/renderer/gl_engine/tvgGlRenderTarget.h b/src/renderer/gl_engine/tvgGlRenderTarget.h
index 7577b35e..89a3d5e0 100644
--- a/src/renderer/gl_engine/tvgGlRenderTarget.h
+++ b/src/renderer/gl_engine/tvgGlRenderTarget.h
@@ -44,13 +44,13 @@ public:
     void setViewport(const RenderRegion& vp) { mViewport = vp; }
     const RenderRegion& getViewport() const { return mViewport; }
 
-    bool invalid() const { return mFbo == GL_INVALID_VALUE; }
+    bool invalid() const { return mFbo == 0; }
 
 private:
     uint32_t mWidth = 0;
     uint32_t mHeight = 0;
     RenderRegion mViewport{};
-    GLuint mFbo = GL_INVALID_VALUE;
+    GLuint mFbo = 0;
     GLuint mColorBuffer = 0;
     GLuint mDepthStencilBuffer = 0;
     GLuint mResolveFbo = 0;
diff --git a/src/renderer/gl_engine/tvgGlRenderer.cpp b/src/renderer/gl_engine/tvgGlRenderer.cpp
index 51b44c30..a7baf2af 100644
--- a/src/renderer/gl_engine/tvgGlRenderer.cpp
+++ b/src/renderer/gl_engine/tvgGlRenderer.cpp
@@ -790,7 +790,7 @@ bool GlRenderer::clear()
 bool GlRenderer::target(void* context, int32_t id, uint32_t w, uint32_t h)
 {
     //assume the context zero is invalid
-    if (!context || id == GL_INVALID_VALUE || w == 0 || h == 0) return false;
+    if (!context || w == 0 || h == 0) return false;
 
     if (mContext) currentContext();