From 7f4a986c38d2403bbf8dbbb7eb9c4683e4ea4e29 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Sun, 29 Jun 2014 09:25:54 +0200
Subject: [PATCH] Added Context::detectedDriver().

A general way to detect drivers, which can be later used for applying
driver-specific workarounds. Currently used for disabling
ARB_explicit_uniform_location on AMD drivers.
---
 src/Magnum/CMakeLists.txt                     |  1 +
 src/Magnum/Context.h                          | 31 +++++++++++++
 src/Magnum/Implementation/detectedDriver.cpp  | 46 +++++++++++++++++++
 .../Implementation/setupDriverWorkarounds.cpp |  3 +-
 4 files changed, 79 insertions(+), 2 deletions(-)
 create mode 100644 src/Magnum/Implementation/detectedDriver.cpp

diff --git a/src/Magnum/CMakeLists.txt b/src/Magnum/CMakeLists.txt
index c3b0cf490..dd7499091 100644
--- a/src/Magnum/CMakeLists.txt
+++ b/src/Magnum/CMakeLists.txt
@@ -62,6 +62,7 @@ set(Magnum_SRCS
     Implementation/ShaderProgramState.cpp
     Implementation/State.cpp
     Implementation/TextureState.cpp
+    Implementation/detectedDriver.cpp
     Implementation/maxTextureSize.cpp
     Implementation/setupDriverWorkarounds.cpp
 
diff --git a/src/Magnum/Context.h b/src/Magnum/Context.h
index 93eee5bef..90aa81797 100644
--- a/src/Magnum/Context.h
+++ b/src/Magnum/Context.h
@@ -38,6 +38,7 @@
 #include "Magnum/Magnum.h"
 #include "Magnum/OpenGL.h"
 #include "Magnum/visibility.h"
+#include "MagnumExternal/Optional/optional.hpp"
 
 namespace Magnum {
 
@@ -169,6 +170,25 @@ class MAGNUM_EXPORT Context {
          */
         typedef Containers::EnumSet<State> States;
 
+        /**
+         * @brief Detected driver
+         *
+         * @see @ref DetectedDriver, @ref detectedDriver()
+         */
+        enum class DetectedDriver: UnsignedShort {
+            #ifndef MAGNUM_TARGET_GLES
+            /** Binary AMD desktop drivers on Windows and Linux */
+            AMD = 1 << 0
+            #endif
+        };
+
+        /**
+         * @brief Detected drivers
+         *
+         * @see @ref detectedDriver()
+         */
+        typedef Containers::EnumSet<DetectedDriver> DetectedDrivers;
+
         /**
          * @brief Constructor
          *
@@ -432,6 +452,15 @@ class MAGNUM_EXPORT Context {
          */
         void resetState(States states = ~States{});
 
+        /**
+         * @brief Detect driver
+         *
+         * Tries to detect driver using various OpenGL state queries. Once the
+         * detection is done, the result is cached, repeated queries don't
+         * result in repeated GL calls.
+         */
+        DetectedDrivers detectedDriver();
+
         #ifndef DOXYGEN_GENERATING_OUTPUT
         Implementation::State& state() { return *_state; }
         #endif
@@ -451,6 +480,8 @@ class MAGNUM_EXPORT Context {
         std::vector<Extension> _supportedExtensions;
 
         Implementation::State* _state;
+
+        std::optional<DetectedDrivers> _detectedDrivers;
 };
 
 /** @debugoperatorclassenum{Magnum::Context,Magnum::Context::Flag} */
diff --git a/src/Magnum/Implementation/detectedDriver.cpp b/src/Magnum/Implementation/detectedDriver.cpp
new file mode 100644
index 000000000..d672bb71e
--- /dev/null
+++ b/src/Magnum/Implementation/detectedDriver.cpp
@@ -0,0 +1,46 @@
+/*
+    This file is part of Magnum.
+
+    Copyright © 2010, 2011, 2012, 2013, 2014
+              Vladimír Vondruš <mosra@centrum.cz>
+
+    Permission is hereby granted, free of charge, to any person obtaining a
+    copy of this software and associated documentation files (the "Software"),
+    to deal in the Software without restriction, including without limitation
+    the rights to use, copy, modify, merge, publish, distribute, sublicense,
+    and/or sell copies of the Software, and to permit persons to whom the
+    Software is furnished to do so, subject to the following conditions:
+
+    The above copyright notice and this permission notice shall be included
+    in all copies or substantial portions of the Software.
+
+    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+    IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+    THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+    LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+    FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+    DEALINGS IN THE SOFTWARE.
+*/
+
+#include "Magnum/Context.h"
+#include "Magnum/Math/Range.h"
+
+namespace Magnum {
+
+auto Context::detectedDriver() -> Context::DetectedDrivers {
+    if(_detectedDrivers) return *_detectedDrivers;
+
+    _detectedDrivers = DetectedDrivers{};
+
+    /* AMD binary desktop drivers */
+    #ifndef MAGNUM_TARGET_GLES
+    const std::string vendor = vendorString();
+    if(vendor.find("ATI Technologies Inc.") != std::string::npos)
+        return *_detectedDrivers |= DetectedDriver::AMD;
+    #endif
+
+    return *_detectedDrivers;
+}
+
+}
diff --git a/src/Magnum/Implementation/setupDriverWorkarounds.cpp b/src/Magnum/Implementation/setupDriverWorkarounds.cpp
index a29332253..ca7c0bb70 100644
--- a/src/Magnum/Implementation/setupDriverWorkarounds.cpp
+++ b/src/Magnum/Implementation/setupDriverWorkarounds.cpp
@@ -35,8 +35,7 @@ void Context::setupDriverWorkarounds() {
 
     #ifndef MAGNUM_TARGET_GLES
     /* This extension causes crash in GLSL compiler on AMD linux drivers 13.251 */
-    const std::string vendor = vendorString();
-    if(vendor.find("ATI Technologies Inc.") != std::string::npos)
+    if(detectedDriver() & DetectedDriver::AMD)
         _setRequiredVersion(GL::ARB::explicit_uniform_location, None);
     #endif