From d7f38ab4bf7d118f8dd3fa13f5defd345599b506 Mon Sep 17 00:00:00 2001
From: Hans-Kristian Arntzen <hans-kristian.arntzen@arm.com>
Date: Tue, 15 Aug 2017 13:28:16 +0200
Subject: [PATCH] Add support for SPV_KHR_multiview.

---
 .../vulkan/vert/multiview.nocompat.vk.vert        | 15 +++++++++++++++
 .../vulkan/vert/multiview.nocompat.vk.vert.vk     | 15 +++++++++++++++
 shaders/vulkan/vert/multiview.nocompat.vk.vert    | 14 ++++++++++++++
 spirv_glsl.cpp                                    | 12 ++++++++++++
 4 files changed, 56 insertions(+)
 create mode 100644 reference/shaders/vulkan/vert/multiview.nocompat.vk.vert
 create mode 100644 reference/shaders/vulkan/vert/multiview.nocompat.vk.vert.vk
 create mode 100644 shaders/vulkan/vert/multiview.nocompat.vk.vert

diff --git a/reference/shaders/vulkan/vert/multiview.nocompat.vk.vert b/reference/shaders/vulkan/vert/multiview.nocompat.vk.vert
new file mode 100644
index 00000000..533738ef
--- /dev/null
+++ b/reference/shaders/vulkan/vert/multiview.nocompat.vk.vert
@@ -0,0 +1,15 @@
+#version 310 es
+#extension GL_OVR_multiview2 : require
+
+layout(binding = 0, std140) uniform MVPs
+{
+    mat4 MVP[2];
+} _19;
+
+layout(location = 0) in vec4 Position;
+
+void main()
+{
+    gl_Position = _19.MVP[gl_ViewID_OVR] * Position;
+}
+
diff --git a/reference/shaders/vulkan/vert/multiview.nocompat.vk.vert.vk b/reference/shaders/vulkan/vert/multiview.nocompat.vk.vert.vk
new file mode 100644
index 00000000..90055473
--- /dev/null
+++ b/reference/shaders/vulkan/vert/multiview.nocompat.vk.vert.vk
@@ -0,0 +1,15 @@
+#version 310 es
+#extension GL_EXT_multiview : require
+
+layout(set = 0, binding = 0, std140) uniform MVPs
+{
+    mat4 MVP[2];
+} _19;
+
+layout(location = 0) in vec4 Position;
+
+void main()
+{
+    gl_Position = _19.MVP[gl_ViewIndex] * Position;
+}
+
diff --git a/shaders/vulkan/vert/multiview.nocompat.vk.vert b/shaders/vulkan/vert/multiview.nocompat.vk.vert
new file mode 100644
index 00000000..eb1bc766
--- /dev/null
+++ b/shaders/vulkan/vert/multiview.nocompat.vk.vert
@@ -0,0 +1,14 @@
+#version 310 es
+#extension GL_EXT_multiview : require
+
+layout(std140, binding = 0) uniform MVPs
+{
+	mat4 MVP[2];
+};
+
+layout(location = 0) in vec4 Position;
+
+void main()
+{
+	gl_Position = MVP[gl_ViewIndex] * Position;
+}
diff --git a/spirv_glsl.cpp b/spirv_glsl.cpp
index e29ae884..a449f9dc 100644
--- a/spirv_glsl.cpp
+++ b/spirv_glsl.cpp
@@ -3619,6 +3619,18 @@ string CompilerGLSL::builtin_to_glsl(BuiltIn builtin, StorageClass storage)
 			SPIRV_CROSS_THROW("gl_SamplePosition not supported before GLSL 400.");
 		return "gl_SamplePosition";
 
+	case BuiltInViewIndex:
+		if (options.vulkan_semantics)
+		{
+			require_extension("GL_EXT_multiview");
+			return "gl_ViewIndex";
+		}
+		else
+		{
+			require_extension("GL_OVR_multiview2");
+			return "gl_ViewID_OVR";
+		}
+
 	default:
 		return join("gl_BuiltIn_", convert_to_string(builtin));
 	}