Added numBackBuffers to initialization parameters.

include/bgfx/bgfx.h

@@ -612,6 +612,7 @@ namespace bgfx
 		uint32_t width;             //!< Backbuffer width.
 		uint32_t height;            //!< Backbuffer height.
 		uint32_t reset;	            //!< Reset parameters.
+		uint8_t  numBackBuffers;    //!< Number of back buffers.
 		uint8_t  maxFrameLatency;   //!< Maximum frame latency.
 	};
 

include/bgfx/c99/bgfx.h

@@ -603,6 +603,7 @@ typedef struct bgfx_resolution_s
     uint32_t width;
     uint32_t height;
     uint32_t reset;
+    uint8_t  numBackBuffers;
     uint8_t  maxFrameLatency;
 
 } bgfx_resolution_t;

include/bgfx/defines.h

@@ -6,7 +6,7 @@
 #ifndef BGFX_DEFINES_H_HEADER_GUARD
 #define BGFX_DEFINES_H_HEADER_GUARD
 
-#define BGFX_API_VERSION UINT32_C(84)
+#define BGFX_API_VERSION UINT32_C(85)
 
 /// Color RGB/alpha/depth write. When it's not specified write will be disabled.
 #define BGFX_STATE_WRITE_R                 UINT64_C(0x0000000000000001) //!< Enable R write.

src/bgfx.cpp

@@ -2822,6 +2822,7 @@ namespace bgfx
 		, width(1280)
 		, height(720)
 		, reset(BGFX_RESET_NONE)
+		, numBackBuffers(2)
 		, maxFrameLatency(0)
 	{
 	}

src/config.h

@@ -326,4 +326,8 @@ BX_STATIC_ASSERT(bx::isPowerOf2(BGFX_CONFIG_MAX_VIEWS), "BGFX_CONFIG_MAX_VIEWS m
 #	define BGFX_CONFIG_DEFAULT_MAX_ENCODERS ( (0 != BGFX_CONFIG_MULTITHREADED) ? 8 : 1)
 #endif // BGFX_CONFIG_DEFAULT_MAX_ENCODERS
 
+#ifndef BGFX_CONFIG_MAX_BACK_BUFFERS
+#	define BGFX_CONFIG_MAX_BACK_BUFFERS 4
+#endif // BGFX_CONFIG_MAX_BACK_BUFFERS
+
 #endif // BGFX_CONFIG_H_HEADER_GUARD

src/renderer_d3d11.cpp

@@ -967,13 +967,15 @@ namespace bgfx { namespace d3d11
 				{
 					HRESULT hr = S_OK;
 
+					m_swapEffect =
 #if BX_PLATFORM_WINDOWS
-					m_swapEffect      = DXGI_SWAP_EFFECT_FLIP_DISCARD;
-					m_swapBufferCount = 2;
+						DXGI_SWAP_EFFECT_FLIP_DISCARD
 #else
-					m_swapEffect      = DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL;
-					m_swapBufferCount = 2;
+						DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL
 #endif // !BX_PLATFORM_WINDOWS
+						;
+
+					m_swapBufferCount = bx::clamp<uint8_t>(_init.resolution.numBackBuffers, 2, BGFX_CONFIG_MAX_BACK_BUFFERS);
 
 					bx::memSet(&m_scd, 0, sizeof(m_scd) );
 					m_scd.width  = _init.resolution.width;

src/renderer_d3d12.cpp

@@ -890,7 +890,7 @@ namespace bgfx { namespace d3d12
 				m_scd.sampleDesc = s_msaa[(_init.resolution.reset&BGFX_RESET_MSAA_MASK)>>BGFX_RESET_MSAA_SHIFT];
 
 				m_scd.bufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
-				m_scd.bufferCount = bx::uint32_min(BX_COUNTOF(m_backBufferColor), 4);
+				m_scd.bufferCount = bx::clamp<uint8_t>(_init.resolution.numBackBuffers, 2, BX_COUNTOF(m_backBufferColor) );
 				m_scd.scaling = 0 == g_platformData.ndt
 					? DXGI_SCALING_NONE
 					: DXGI_SCALING_STRETCH
@@ -3213,11 +3213,11 @@ namespace bgfx { namespace d3d12
 		D3D12_CPU_DESCRIPTOR_HANDLE m_dsvHandle;
 		D3D12_CPU_DESCRIPTOR_HANDLE* m_currentColor;
 		D3D12_CPU_DESCRIPTOR_HANDLE* m_currentDepthStencil;
-		ID3D12Resource* m_backBufferColor[4];
-		uint64_t m_backBufferColorFence[4];
+		ID3D12Resource* m_backBufferColor[BGFX_CONFIG_MAX_BACK_BUFFERS];
+		uint64_t m_backBufferColorFence[BGFX_CONFIG_MAX_BACK_BUFFERS];
 		ID3D12Resource* m_backBufferDepthStencil;
 
-		ScratchBufferD3D12 m_scratchBuffer[4];
+		ScratchBufferD3D12 m_scratchBuffer[BGFX_CONFIG_MAX_BACK_BUFFERS];
 		DescriptorAllocatorD3D12 m_samplerAllocator;
 
 		ID3D12RootSignature*    m_rootSignature;

src/renderer_d3d9.cpp

@@ -425,8 +425,8 @@ namespace bgfx { namespace d3d9
 			m_params.BackBufferWidth  = _init.resolution.width;
 			m_params.BackBufferHeight = _init.resolution.height;
 			m_params.BackBufferFormat = adapterFormat;
-			m_params.BackBufferCount = 1;
-			m_params.MultiSampleType = D3DMULTISAMPLE_NONE;
+			m_params.BackBufferCount  = bx::clamp<uint8_t>(_init.resolution.numBackBuffers, 2, BGFX_CONFIG_MAX_BACK_BUFFERS);
+			m_params.MultiSampleType  = D3DMULTISAMPLE_NONE;
 			m_params.MultiSampleQuality = 0;
 			m_params.EnableAutoDepthStencil = TRUE;
 			m_params.AutoDepthStencilFormat = D3DFMT_D24S8;

src/renderer_mtl.mm

@@ -484,9 +484,9 @@ namespace bgfx { namespace mtl
 			m_textureDescriptor = newTextureDescriptor();
 			m_samplerDescriptor = newSamplerDescriptor();
 
-			for (uint8_t i=0; i < MTL_MAX_FRAMES_IN_FLIGHT; ++i)
+			for (uint8_t ii = 0; ii < MTL_MAX_FRAMES_IN_FLIGHT; ++ii)
 			{
-				m_uniformBuffers[i] = m_device.newBufferWithLength(UNIFORM_BUFFER_SIZE, 0);
+				m_uniformBuffers[ii] = m_device.newBufferWithLength(UNIFORM_BUFFER_SIZE, 0);
 			}
 
 			m_uniformBufferVertexOffset   = 0;
@@ -571,6 +571,7 @@ namespace bgfx { namespace mtl
 				g_caps.limits.maxFBAttachments = 8;
 				g_caps.supported |= BGFX_CAPS_TEXTURE_CUBE_ARRAY;
 			}
+
 			g_caps.limits.maxTextureLayers = 2048;
 			g_caps.limits.maxVertexStreams = BGFX_CONFIG_MAX_VERTEX_STREAMS;
 
@@ -676,7 +677,7 @@ namespace bgfx { namespace mtl
 				}
 			}
 
-			for (uint32_t ii=1; ii<5; ++ii)
+			for (uint32_t ii = 1; ii < 5; ++ii)
 			{
 				if (!m_device.supportsTextureSampleCount(s_msaa[ii]) )
 				{

tools/shaderc/shaderc.cpp

@@ -18,7 +18,7 @@ extern "C"
 #define BGFX_CHUNK_MAGIC_VSH BX_MAKEFOURCC('V', 'S', 'H', 0x5)
 
 #define BGFX_SHADERC_VERSION_MAJOR 1
-#define BGFX_SHADERC_VERSION_MINOR 14
+#define BGFX_SHADERC_VERSION_MINOR 15
 
 namespace bgfx
 {