From 859913939f79838d2ae14242a5525b5fa4c7f329 Mon Sep 17 00:00:00 2001
From: WebFreak001 <gh@webfreak.org>
Date: Thu, 25 Jan 2024 00:34:47 +0100
Subject: [PATCH] fix nanovega tainting the active VAO

this is both needed for modern opengl because if you are unlucky with your graphics drivers there it won't render anything when the core context is enabled, but also when rendering custom data and having stray VAOs open that you didn't unbind on the start of the nanovega render calls.

stuff like `glEnableVertexAttribArray` and `glVertexAttribPointer`, which is called below, is only valid with a VAO bound.
---
 nanovega.d | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/nanovega.d b/nanovega.d
index c50f308..fbfa4a3 100644
--- a/nanovega.d
+++ b/nanovega.d
@@ -12516,6 +12516,7 @@ struct GLNVGcontext {
   int freetexid; // -1: none
   int ntextures;
   int ctextures;
+  GLuint vaoBuf;
   GLuint vertBuf;
   int fragSize;
   int flags;
@@ -13273,6 +13274,8 @@ bool glnvg__renderCreate (void* uptr) nothrow @trusted @nogc {
   glnvg__getUniforms(&gl.shaderFillFBO);
   glnvg__getUniforms(&gl.shaderCopyFBO);
 
+  // Create VAO (required for modern OpenGL compatibility)
+  glGenVertexArrays(1, &gl.vaoBuf);
   // Create dynamic vertex array
   glGenBuffers(1, &gl.vertBuf);
 
@@ -14006,6 +14009,7 @@ void glnvg__renderFlush (void* uptr) nothrow @trusted @nogc {
     }
     glnvg__checkError(gl, "OpenGL setup");
 
+    glBindVertexArray(gl.vaoBuf);
     // Upload vertex data
     glBindBuffer(GL_ARRAY_BUFFER, gl.vertBuf);
     // ensure that there's space for at least 4 vertices in case we need to draw a quad (e. g. framebuffer copy)
@@ -14129,6 +14133,7 @@ void glnvg__renderFlush (void* uptr) nothrow @trusted @nogc {
     glDisableVertexAttribArray(1);
     glDisable(GL_CULL_FACE);
     glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindVertexArray(0);
     glUseProgram(0);
     glnvg__bindTexture(gl, 0);
   }
@@ -14407,6 +14412,7 @@ void glnvg__renderDelete (void* uptr) nothrow @trusted @nogc {
   glnvg__deleteShader(&gl.shaderFillFBO);
   glnvg__deleteShader(&gl.shaderCopyFBO);
 
+  if (gl.vaoBuf != 0) glDeleteVertexArrays(1, &gl.vaoBuf);
   if (gl.vertBuf != 0) glDeleteBuffers(1, &gl.vertBuf);
 
   foreach (ref GLNVGtexture tex; gl.textures[0..gl.ntextures]) {