From 8c204efafb122eb13d9dad8a48504ed79a586ec0 Mon Sep 17 00:00:00 2001
From: Alex Szpakowski <slime73@gmail.com>
Date: Thu, 5 Jan 2017 22:33:10 -0400
Subject: [PATCH] Minor pre-emptive fixes for GL3.

--HG--
branch : minor
---
 src/modules/graphics/opengl/Graphics.cpp | 18 ++++++++++++++++--
 src/modules/graphics/opengl/Graphics.h   |  2 ++
 src/modules/graphics/opengl/OpenGL.cpp   | 24 ++++++++++++++++++++++--
 src/modules/graphics/opengl/OpenGL.h     |  7 +++++++
 4 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/src/modules/graphics/opengl/Graphics.cpp b/src/modules/graphics/opengl/Graphics.cpp
index 45e61a8ac..f059950a7 100644
--- a/src/modules/graphics/opengl/Graphics.cpp
+++ b/src/modules/graphics/opengl/Graphics.cpp
@@ -56,6 +56,7 @@ namespace opengl
 Graphics::Graphics()
 	: quadIndices(nullptr)
 	, windowHasStencil(false)
+	, mainVAO(0)
 {
 	gl = OpenGL();
 
@@ -224,9 +225,10 @@ bool Graphics::setMode(int width, int height, int pixelwidth, int pixelheight, b
 	glEnable(GL_BLEND);
 
 	// Auto-generated mipmaps should be the best quality possible
-	glHint(GL_GENERATE_MIPMAP_HINT, GL_NICEST);
+	if (!gl.isCoreProfile())
+		glHint(GL_GENERATE_MIPMAP_HINT, GL_NICEST);
 
-	if (!GLAD_ES_VERSION_2_0)
+	if (!GLAD_ES_VERSION_2_0 && !gl.isCoreProfile())
 	{
 		// Make sure antialiasing works when set elsewhere
 		glEnable(GL_MULTISAMPLE);
@@ -235,6 +237,12 @@ bool Graphics::setMode(int width, int height, int pixelwidth, int pixelheight, b
 		glEnable(GL_TEXTURE_2D);
 	}
 
+	if (gl.isCoreProfile())
+	{
+		glGenVertexArrays(1, &mainVAO);
+		glBindVertexArray(mainVAO);
+	}
+
 	gl.setTextureUnit(0);
 
 	// Set pixel row alignment
@@ -334,6 +342,12 @@ void Graphics::unSetMode()
 	framebufferObjects.clear();
 	stencilBuffers.clear();
 
+	if (mainVAO != 0)
+	{
+		glDeleteVertexArrays(1, &mainVAO);
+		mainVAO = 0;
+	}
+
 	gl.deInitContext();
 
 	created = false;
diff --git a/src/modules/graphics/opengl/Graphics.h b/src/modules/graphics/opengl/Graphics.h
index c05ce7151..08dfcfa38 100644
--- a/src/modules/graphics/opengl/Graphics.h
+++ b/src/modules/graphics/opengl/Graphics.h
@@ -157,6 +157,8 @@ private:
 
 	bool windowHasStencil;
 
+	GLuint mainVAO;
+
 }; // Graphics
 
 } // opengl
diff --git a/src/modules/graphics/opengl/OpenGL.cpp b/src/modules/graphics/opengl/OpenGL.cpp
index e8679179d..38f3c0b86 100644
--- a/src/modules/graphics/opengl/OpenGL.cpp
+++ b/src/modules/graphics/opengl/OpenGL.cpp
@@ -73,6 +73,8 @@ OpenGL::OpenGL()
 	, maxRenderTargets(1)
 	, maxRenderbufferSamples(0)
 	, maxTextureUnits(1)
+	, maxPointSize(1)
+	, coreProfile(false)
 	, vendor(VENDOR_UNKNOWN)
 	, state()
 {
@@ -90,6 +92,15 @@ bool OpenGL::initContext()
 	if (!gladLoadGLLoader(LOVEGetProcAddress))
 		return false;
 
+	if (GLAD_VERSION_3_2)
+	{
+		GLint profileMask = 0;
+		glGetIntegerv(GL_CONTEXT_PROFILE_MASK, &profileMask);
+		coreProfile = (profileMask & GL_CONTEXT_CORE_PROFILE_BIT);
+	}
+	else
+		coreProfile = false;
+
 	initOpenGLFunctions();
 	initVendor();
 
@@ -100,7 +111,8 @@ bool OpenGL::initContext()
 	if (getVendor() == VENDOR_AMD)
 	{
 		bugs.clearRequiresDriverTextureStateUpdate = true;
-		bugs.generateMipmapsRequiresTexture2DEnable = true;
+		if (!gl.isCoreProfile())
+			bugs.generateMipmapsRequiresTexture2DEnable = true;
 	}
 #endif
 
@@ -306,7 +318,10 @@ void OpenGL::initMaxValues()
 	glGetIntegerv(GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, &maxTextureUnits);
 
 	GLfloat limits[2];
-	glGetFloatv(GL_ALIASED_POINT_SIZE_RANGE, limits);
+	if (GLAD_VERSION_3_0)
+		glGetFloatv(GL_POINT_SIZE_RANGE, limits);
+	else
+		glGetFloatv(GL_ALIASED_POINT_SIZE_RANGE, limits);
 	maxPointSize = limits[1];
 }
 
@@ -741,6 +756,11 @@ void OpenGL::updateTextureMemorySize(size_t oldsize, size_t newsize)
 	stats.textureMemory = (size_t) std::max(memsize, (int64) 0);
 }
 
+bool OpenGL::isCoreProfile() const
+{
+	return coreProfile;
+}
+
 OpenGL::Vendor OpenGL::getVendor() const
 {
 	return vendor;
diff --git a/src/modules/graphics/opengl/OpenGL.h b/src/modules/graphics/opengl/OpenGL.h
index 47056cc3d..9ee4a303d 100644
--- a/src/modules/graphics/opengl/OpenGL.h
+++ b/src/modules/graphics/opengl/OpenGL.h
@@ -347,6 +347,11 @@ public:
 
 	void updateTextureMemorySize(size_t oldsize, size_t newsize);
 
+	/**
+	 * Gets whether the context is Core Profile OpenGL 3.2+.
+	 **/
+	bool isCoreProfile() const;
+
 	/**
 	 * Get the GPU vendor of this OpenGL context.
 	 **/
@@ -385,6 +390,8 @@ private:
 	int maxTextureUnits;
 	float maxPointSize;
 
+	bool coreProfile;
+
 	Vendor vendor;
 
 	// Tracked OpenGL state.