From 7bfe51d0d8c689839814bc17739785baa3ad515e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Branimir=20Karad=C5=BEi=C4=87?= <branimirkaradzic@gmail.com>
Date: Tue, 14 Apr 2015 20:03:05 -0700
Subject: [PATCH] Added flip after submit reset flag.

---
 examples/common/entry/entry.cpp | 15 +++++++++------
 include/bgfx.h                  |  5 +++++
 include/bgfxdefines.h           |  1 +
 src/bgfx.cpp                    | 11 ++++++++++-
 src/bgfx_p.h                    |  4 ++++
 5 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/examples/common/entry/entry.cpp b/examples/common/entry/entry.cpp
index 4eb25a51a..e9d00e32c 100644
--- a/examples/common/entry/entry.cpp
+++ b/examples/common/entry/entry.cpp
@@ -118,12 +118,14 @@ BX_PRAGMA_DIAGNOSTIC_POP();
 	{
 		if (_argc > 1)
 		{
-			if (setOrToggle(s_reset, "vsync",       BGFX_RESET_VSYNC,         1, _argc, _argv)
-			||  setOrToggle(s_reset, "maxaniso",    BGFX_RESET_MAXANISOTROPY, 1, _argc, _argv)
-			||  setOrToggle(s_reset, "hmd",         BGFX_RESET_HMD,           1, _argc, _argv)
-			||  setOrToggle(s_reset, "hmddbg",      BGFX_RESET_HMD_DEBUG,     1, _argc, _argv)
-			||  setOrToggle(s_reset, "hmdrecenter", BGFX_RESET_HMD_RECENTER,  1, _argc, _argv)
-			||  setOrToggle(s_reset, "msaa",        BGFX_RESET_MSAA_X16,      1, _argc, _argv) )
+			if (setOrToggle(s_reset, "vsync",       BGFX_RESET_VSYNC,             1, _argc, _argv)
+			||  setOrToggle(s_reset, "maxaniso",    BGFX_RESET_MAXANISOTROPY,     1, _argc, _argv)
+			||  setOrToggle(s_reset, "hmd",         BGFX_RESET_HMD,               1, _argc, _argv)
+			||  setOrToggle(s_reset, "hmddbg",      BGFX_RESET_HMD_DEBUG,         1, _argc, _argv)
+			||  setOrToggle(s_reset, "hmdrecenter", BGFX_RESET_HMD_RECENTER,      1, _argc, _argv)
+			||  setOrToggle(s_reset, "msaa",        BGFX_RESET_MSAA_X16,          1, _argc, _argv)
+			||  setOrToggle(s_reset, "flip",        BGFX_RESET_FLIP_AFTER_SUBMIT, 1, _argc, _argv)
+			   )
 			{
 				return 0;
 			}
@@ -176,6 +178,7 @@ BX_PRAGMA_DIAGNOSTIC_POP();
 		{ entry::Key::F4,           entry::Modifier::LeftCtrl,  1, cmd, "graphics hmddbg"                   },
 		{ entry::Key::F7,           entry::Modifier::None,      1, cmd, "graphics vsync"                    },
 		{ entry::Key::F8,           entry::Modifier::None,      1, cmd, "graphics msaa"                     },
+		{ entry::Key::F9,           entry::Modifier::None,      1, cmd, "graphics flip"                     },
 		{ entry::Key::Print,        entry::Modifier::None,      1, cmd, "graphics screenshot"               },
 
 		INPUT_BINDING_END
diff --git a/include/bgfx.h b/include/bgfx.h
index 2577d1d66..5db0a87f9 100644
--- a/include/bgfx.h
+++ b/include/bgfx.h
@@ -571,7 +571,12 @@ namespace bgfx
 	///   - `BGFX_RESET_FULLSCREEN` - Not supported yet.
 	///   - `BGFX_RESET_MSAA_X[2/4/8/16]` - Enable 2, 4, 8 or 16 x MSAA.
 	///   - `BGFX_RESET_VSYNC` - Enable V-Sync.
+	///   - `BGFX_RESET_MAXANISOTROPY` - Turn on/off max anisotropy.
 	///   - `BGFX_RESET_CAPTURE` - Begin screen capture.
+	///   - `BGFX_RESET_HMD` - HMD stereo rendering.
+	///   - `BGFX_RESET_HMD_DEBUG` - HMD stereo rendering debug mode.
+	///   - `BGFX_RESET_HMD_RECENTER` - HMD calibration.
+	///   - `BGFX_RESET_FLIP_AFTER_SUBMIT` - Flip back buffer after submit.
 	///
 	/// @attention This call doesn't actually change window size, it just
 	///   resizes back-buffer. Windowing code has to change window size.
diff --git a/include/bgfxdefines.h b/include/bgfxdefines.h
index 1c8a894a3..d35176219 100644
--- a/include/bgfxdefines.h
+++ b/include/bgfxdefines.h
@@ -303,6 +303,7 @@
 #define BGFX_RESET_HMD                   UINT32_C(0x00000400)
 #define BGFX_RESET_HMD_DEBUG             UINT32_C(0x00000800)
 #define BGFX_RESET_HMD_RECENTER          UINT32_C(0x00001000)
+#define BGFX_RESET_FLIP_AFTER_SUBMIT     UINT32_C(0x00002000)
 
 ///
 #define BGFX_CAPS_TEXTURE_COMPARE_LEQUAL UINT64_C(0x0000000000000001)
diff --git a/src/bgfx.cpp b/src/bgfx.cpp
index 8be7d84d1..1f26f2e85 100644
--- a/src/bgfx.cpp
+++ b/src/bgfx.cpp
@@ -1190,6 +1190,8 @@ namespace bgfx
 		m_render = m_submit;
 		m_submit = temp;
 
+		memcpy(&m_submit->m_hmd, &m_render->m_hmd, sizeof(HMD) );
+
 		m_frames++;
 		m_submit->start();
 
@@ -1205,7 +1207,8 @@ namespace bgfx
 
 	bool Context::renderFrame()
 	{
-		if (m_rendererInitialized)
+		if (m_rendererInitialized
+		&&  !m_flipAfterSubmit)
 		{
 			m_renderCtx->flip();
 		}
@@ -1221,6 +1224,12 @@ namespace bgfx
 
 		renderSemPost();
 
+		if (m_rendererInitialized
+		&&  m_flipAfterSubmit)
+		{
+			m_renderCtx->flip();
+		}
+
 		return m_exit;
 	}
 
diff --git a/src/bgfx_p.h b/src/bgfx_p.h
index 2c91b0b52..96b4756d7 100644
--- a/src/bgfx_p.h
+++ b/src/bgfx_p.h
@@ -1893,6 +1893,7 @@ namespace bgfx
 			, m_renderCtx(NULL)
 			, m_rendererInitialized(false)
 			, m_exit(false)
+			, m_flipAfterSubmit(false)
 		{
 		}
 
@@ -1927,6 +1928,8 @@ namespace bgfx
 			m_resolution.m_height = bx::uint32_max(1, _height);
 			m_resolution.m_flags  = _flags;
 
+			m_flipAfterSubmit = !!(_flags & BGFX_RESET_FLIP_AFTER_SUBMIT);
+
 			memset(m_fb, 0xff, sizeof(m_fb) );
 
 			for (uint16_t ii = 0, num = m_textureHandle.getNumHandles(); ii < num; ++ii)
@@ -3527,6 +3530,7 @@ namespace bgfx
 
 		bool m_rendererInitialized;
 		bool m_exit;
+		bool m_flipAfterSubmit;
 
 		typedef UpdateBatchT<256> TextureUpdateBatch;
 		BX_ALIGN_DECL_CACHE_LINE(TextureUpdateBatch m_textureUpdateBatch);