Add support for EGL_PLATFORM_ANGLE_EGL_HANDLE_ANGLE

To support ANGLE for Android need a way to tell ANGLE
what library to call when using GL backend.

Bug: angleproject:2418
Test: test-opengl-gl2_copyTexImage
Change-Id: Ie00251b0672a036db4720e1e5b269f66a30a03da
Reviewed-on: https://chromium-review.googlesource.com/1066822
Commit-Queue: Courtney Goeltzenleuchter <courtneygo@google.com>
Reviewed-by: Frank Henigman <fjhenigman@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>

extensions/EGL_ANGLE_platform_angle_opengl.txt

@@ -10,6 +10,7 @@ Contributors
 
     Shannon Woods, Google
     Geoff Lang, Google
+    Courtney Goeltzenleuchter, Google
 
 Contacts
 
@@ -21,7 +22,7 @@ Status
 
 Version
 
-    Version 3, 2014-11-26
+    Version 4, 2018-05-17
 
 Number
 
@@ -37,7 +38,9 @@ Dependencies
 
 Overview
 
-    This extension enables selection of OpenGL display types.
+    This extension enables selection of OpenGL display types and,
+    for OpenGL ES display types, allows the application to pass
+    in a handle to the EGL library to use.
 
 New Types
 
@@ -54,6 +57,10 @@ New Tokens
         EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE               0x320D
         EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE             0x320E
 
+    Accepted as an attribute name in the <attrib_list> argument of
+    eglGetPlatformDisplayEXT:
+        EGL_PLATFORM_ANGLE_EGL_HANDLE_ANGLE                0x3480
+
 Additions to the EGL Specification
 
     None.
@@ -69,6 +76,13 @@ New Behavior
     API, EGL_PLATFORM_ANGLE_MAX_VERSION_MAJOR_ANGLE and
     EGL_PLATFORM_ANGLE_MAX_VERSION_MINOR_ANGLE can be used.
 
+    To pass in a handle to the system EGL library, use the attribute
+    EGL_PLATFORM_ANGLE_EGL_HANDLE_ANGLE. If EGL_PLATFORM_ANGLE_TYPE_ANGLE
+    is not equal to EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE, an
+    EGL_BAD_ATTRIBUTE is generated. If the handle provided with
+    EGL_PLATFORM_ANGLE_EGL_HANDLE_ANGLE is not a valid EGL handle,
+    behaviour is undefined.
+
 Issues
 
     None
@@ -82,3 +96,5 @@ Revision History
         EGL_ANGLE_platform_angle spec to EGL_ANGLE_platform_angle_opengl.
     Version 3, 2014-11-26 (Geoff Lang)
       - Updated enum values.
+    Version 4, 2018-05-17 (Courtney Goeltzenleuchter)
+      - Add attribute for specifying underlying EGL library.

include/EGL/eglext_angle.h

@@ -69,6 +69,7 @@
 #define EGL_ANGLE_platform_angle_opengl 1
 #define EGL_PLATFORM_ANGLE_TYPE_OPENGL_ANGLE 0x320D
 #define EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE 0x320E
+#define EGL_PLATFORM_ANGLE_EGL_HANDLE_ANGLE 0x3480
 #endif /* EGL_ANGLE_platform_angle_opengl */
 
 #ifndef EGL_ANGLE_platform_angle_null

src/libANGLE/renderer/gl/egl/FunctionsEGLDL.cpp

@@ -32,8 +32,18 @@ FunctionsEGLDL::~FunctionsEGLDL()
 {
 }
 
-egl::Error FunctionsEGLDL::initialize(EGLNativeDisplayType nativeDisplay, const char *libName)
+egl::Error FunctionsEGLDL::initialize(EGLNativeDisplayType nativeDisplay,
+                                      const char *libName,
+                                      void *eglHandle)
 {
+
+    if (eglHandle)
+    {
+        // If the handle is provided, use it.
+        // Caller has already dlopened the vendor library.
+        nativeEGLHandle = eglHandle;
+    }
+
     if (!nativeEGLHandle)
     {
         nativeEGLHandle = dlopen(libName, RTLD_NOW);

src/libANGLE/renderer/gl/egl/FunctionsEGLDL.h

@@ -20,7 +20,7 @@ class FunctionsEGLDL : public FunctionsEGL
     FunctionsEGLDL();
     ~FunctionsEGLDL() override;
 
-    egl::Error initialize(EGLNativeDisplayType nativeDisplay, const char *libName);
+    egl::Error initialize(EGLNativeDisplayType nativeDisplay, const char *libName, void *eglHandle);
     void *getProcAddress(const char *name) const override;
 
   private:

src/libANGLE/renderer/gl/egl/android/DisplayAndroid.cpp

@@ -11,11 +11,11 @@
 #include "common/debug.h"
 #include "libANGLE/Display.h"
 #include "libANGLE/Surface.h"
-#include "libANGLE/renderer/gl/renderergl_utils.h"
-#include "libANGLE/renderer/gl/egl/android/DisplayAndroid.h"
 #include "libANGLE/renderer/gl/egl/FunctionsEGLDL.h"
 #include "libANGLE/renderer/gl/egl/PbufferSurfaceEGL.h"
 #include "libANGLE/renderer/gl/egl/WindowSurfaceEGL.h"
+#include "libANGLE/renderer/gl/egl/android/DisplayAndroid.h"
+#include "libANGLE/renderer/gl/renderergl_utils.h"
 
 namespace
 {
@@ -45,7 +45,9 @@ egl::Error DisplayAndroid::initialize(egl::Display *display)
 {
     FunctionsEGLDL *egl = new FunctionsEGLDL();
     mEGL = egl;
-    ANGLE_TRY(egl->initialize(display->getNativeDisplayId(), GetEGLPath()));
+    void *eglHandle     = reinterpret_cast<void *>(display->getAttributeMap().get(
+        EGL_PLATFORM_ANGLE_EGL_HANDLE_ANGLE, 0));
+    ANGLE_TRY(egl->initialize(display->getNativeDisplayId(), GetEGLPath(), eglHandle));
 
     gl::Version eglVersion(mEGL->majorVersion, mEGL->minorVersion);
     ASSERT(eglVersion >= gl::Version(1, 4));

src/libANGLE/renderer/gl/egl/ozone/DisplayOzone.cpp

@@ -459,7 +459,7 @@ egl::Error DisplayOzone::initialize(egl::Display *display)
     // with a .1 suffix) while Angle only installs libEGL.so.
     FunctionsEGLDL *egl = new FunctionsEGLDL();
     mEGL = egl;
-    ANGLE_TRY(egl->initialize(display->getNativeDisplayId(), "libEGL.so.1"));
+    ANGLE_TRY(egl->initialize(display->getNativeDisplayId(), "libEGL.so.1", nullptr));
 
     const char *necessaryExtensions[] = {
         "EGL_KHR_image_base", "EGL_EXT_image_dma_buf_import", "EGL_KHR_surfaceless_context",

src/libANGLE/validationEGL.cpp

@@ -304,6 +304,7 @@ Error ValidateGetPlatformDisplayCommon(EGLenum platform,
         Optional<EGLAttrib> majorVersion;
         Optional<EGLAttrib> minorVersion;
         Optional<EGLAttrib> deviceType;
+        Optional<EGLAttrib> eglHandle;
 
         for (const auto &curAttrib : attribMap)
         {
@@ -400,6 +401,13 @@ Error ValidateGetPlatformDisplayCommon(EGLenum platform,
                     }
                     break;
 
+                case EGL_PLATFORM_ANGLE_EGL_HANDLE_ANGLE:
+                    if (value != EGL_DONT_CARE)
+                    {
+                        eglHandle = value;
+                    }
+                    break;
+
                 default:
                     break;
             }
@@ -460,6 +468,13 @@ Error ValidateGetPlatformDisplayCommon(EGLenum platform,
                                             "only supports Vulkan 1.0.";
             }
         }
+
+        if (eglHandle.valid() && platformType != EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE &&
+            platformType != EGL_PLATFORM_ANGLE_TYPE_DEFAULT_ANGLE)
+        {
+            return EglBadAttribute() << "EGL_PLATFORM_ANGLE_EGL_HANDLE_ANGLE requires a "
+                                        "device type of EGL_PLATFORM_ANGLE_TYPE_OPENGLES_ANGLE.";
+        }
     }
     else if (platform == EGL_PLATFORM_DEVICE_EXT)
     {