discard flags

bindings/cs/bgfx.cs

@@ -1,5 +1,5 @@
 /*
- * Copyright 2011-2019 Branimir Karadzic. All rights reserved.
+ * Copyright 2011-2020 Branimir Karadzic. All rights reserved.
  * License: https://github.com/bkaradzic/bgfx/blob/master/LICENSE
  */
 
@@ -201,6 +201,38 @@ public static partial class bgfx
 		CullCcw                = 0x0000002000000000,
 		CullShift              = 36,
 		CullMask               = 0x0000003000000000,
+	
+		/// <summary>
+		/// Discard only Index Buffer
+		/// </summary>
+		DiscardIndexBuffer     = 0x0000000000000001,
+	
+		/// <summary>
+		/// Discard only Vertex Streams
+		/// </summary>
+		DiscardVertexStreams   = 0x0000000000000002,
+	
+		/// <summary>
+		/// Discard only texture samplers
+		/// </summary>
+		DiscardTextureSamplers = 0x0000000000000003,
+	
+		/// <summary>
+		/// Discard only Compute shader related state
+		/// </summary>
+		DiscardCompute         = 0x0000000000000004,
+	
+		/// <summary>
+		/// Discard only state
+		/// </summary>
+		DiscardState           = 0x0000000000000005,
+	
+		/// <summary>
+		/// Discard every rendering states
+		/// </summary>
+		DiscardAll             = 0xffffffffffffffff,
+		DiscardShift           = 0,
+		DiscardMask            = 0x0000000000000007,
 		AlphaRefShift          = 40,
 		AlphaRefMask           = 0x0000ff0000000000,
 	
@@ -3787,11 +3819,13 @@ public static partial class bgfx
 	public static extern unsafe void encoder_dispatch_indirect(Encoder* _this, ushort _id, ProgramHandle _program, IndirectBufferHandle _indirectHandle, ushort _start, ushort _num);
 	
 	/// <summary>
-	/// Discard all previously set state for draw or compute call.
+	/// Discard previously set state for draw or compute call.
 	/// </summary>
 	///
+	/// <param name="_flags">rendering states to discard</param>
+	///
 	[DllImport(DllName, EntryPoint="bgfx_encoder_discard", CallingConvention = CallingConvention.Cdecl)]
-	public static extern unsafe void encoder_discard(Encoder* _this);
+	public static extern unsafe void encoder_discard(Encoder* _this, ulong _flags);
 	
 	/// <summary>
 	/// Blit 2D texture region between two 2D textures.
@@ -4300,11 +4334,13 @@ public static partial class bgfx
 	public static extern unsafe void dispatch_indirect(ushort _id, ProgramHandle _program, IndirectBufferHandle _indirectHandle, ushort _start, ushort _num);
 	
 	/// <summary>
-	/// Discard all previously set state for draw or compute call.
+	/// Discard previously set state for draw or compute call.
 	/// </summary>
 	///
+	/// <param name="_flags">rendering states to discard</param>
+	///
 	[DllImport(DllName, EntryPoint="bgfx_discard", CallingConvention = CallingConvention.Cdecl)]
-	public static extern unsafe void discard();
+	public static extern unsafe void discard(ulong _flags);
 	
 	/// <summary>
 	/// Blit 2D texture region between two 2D textures.

bindings/d/funcs.d

@@ -1571,9 +1571,11 @@ version(BindBgfx_Static)
 	void bgfx_encoder_dispatch_indirect(bgfx_encoder_t* _this, bgfx_view_id_t _id, bgfx_program_handle_t _program, bgfx_indirect_buffer_handle_t _indirectHandle, ushort _start, ushort _num);
 	
 	/**
-	 * Discard all previously set state for draw or compute call.
+	 * Discard previously set state for draw or compute call.
+	 * Params:
+	 * _flags = rendering states to discard
 	 */
-	void bgfx_encoder_discard(bgfx_encoder_t* _this);
+	void bgfx_encoder_discard(bgfx_encoder_t* _this, ulong _flags);
 	
 	/**
 	 * Blit 2D texture region between two 2D textures.
@@ -2028,9 +2030,11 @@ version(BindBgfx_Static)
 	void bgfx_dispatch_indirect(bgfx_view_id_t _id, bgfx_program_handle_t _program, bgfx_indirect_buffer_handle_t _indirectHandle, ushort _start, ushort _num);
 	
 	/**
-	 * Discard all previously set state for draw or compute call.
+	 * Discard previously set state for draw or compute call.
+	 * Params:
+	 * _flags = rendering states to discard
 	 */
-	void bgfx_discard();
+	void bgfx_discard(ulong _flags);
 	
 	/**
 	 * Blit 2D texture region between two 2D textures.
@@ -3763,9 +3767,11 @@ else
 		da_bgfx_encoder_dispatch_indirect bgfx_encoder_dispatch_indirect;
 		
 		/**
-		 * Discard all previously set state for draw or compute call.
+		 * Discard previously set state for draw or compute call.
+		 * Params:
+		 * _flags = rendering states to discard
 		 */
-		alias da_bgfx_encoder_discard = void function(bgfx_encoder_t* _this);
+		alias da_bgfx_encoder_discard = void function(bgfx_encoder_t* _this, ulong _flags);
 		da_bgfx_encoder_discard bgfx_encoder_discard;
 		
 		/**
@@ -4262,9 +4268,11 @@ else
 		da_bgfx_dispatch_indirect bgfx_dispatch_indirect;
 		
 		/**
-		 * Discard all previously set state for draw or compute call.
+		 * Discard previously set state for draw or compute call.
+		 * Params:
+		 * _flags = rendering states to discard
 		 */
-		alias da_bgfx_discard = void function();
+		alias da_bgfx_discard = void function(ulong _flags);
 		da_bgfx_discard bgfx_discard;
 		
 		/**

bindings/d/types.d

@@ -75,6 +75,16 @@ enum ulong BGFX_STATE_CULL_CCW = 0x0000002000000000; /// Cull counter-clockwise
 enum ulong BGFX_STATE_CULL_SHIFT = 36; /// Culling mode bit shift
 enum ulong BGFX_STATE_CULL_MASK = 0x0000003000000000; /// Culling mode bit mask
 
+/// Rendering state discard. When state is preserved in submit, rendering states can be discarded on a finer grain.
+enum ulong BGFX_STATE_DISCARD_INDEX_BUFFER = 0x0000000000000001; /// Discard only Index Buffer
+enum ulong BGFX_STATE_DISCARD_VERTEX_STREAMS = 0x0000000000000002; /// Discard only Vertex Streams
+enum ulong BGFX_STATE_DISCARD_TEXTURE_SAMPLERS = 0x0000000000000003; /// Discard only texture samplers
+enum ulong BGFX_STATE_DISCARD_COMPUTE = 0x0000000000000004; /// Discard only Compute shader related state
+enum ulong BGFX_STATE_DISCARD_STATE = 0x0000000000000005; /// Discard only state
+enum ulong BGFX_STATE_DISCARD_ALL = 0xffffffffffffffff; /// Discard every rendering states
+enum ulong BGFX_STATE_DISCARD_SHIFT = 0; /// Discard flags bit shift
+enum ulong BGFX_STATE_DISCARD_MASK = 0x0000000000000007; /// Discard flags bit mask
+
 /// Alpha reference value.
 enum ulong BGFX_STATE_ALPHA_REF_SHIFT = 40; /// Alpha reference bit shift
 enum ulong BGFX_STATE_ALPHA_REF_MASK = 0x0000ff0000000000; /// Alpha reference bit mask

examples/23-vectordisplay/vectordisplay.cpp

@@ -272,7 +272,7 @@ void VectorDisplay::endFrame()
 		}
 	}
 
-	bgfx::discard();
+	bgfx::discard(BGFX_STATE_DISCARD_ALL);
 
 	//now do last pass, combination of blur and normal buffer to screen
 	bgfx::setViewTransform(viewCounter, NULL, proj);

include/bgfx/bgfx.h

@@ -1590,7 +1590,7 @@ namespace bgfx
 		///
 		/// @attention C99 equivalent is `bgfx_encoder_discard`.
 		///
-		void discard();
+		void discard(uint64_t flags);
 
 		/// Blit texture 2D region between two 2D textures.
 		///
@@ -3985,7 +3985,7 @@ namespace bgfx
 	///
 	/// @attention C99 equivalent is `bgfx_discard`.
 	///
-	void discard();
+	void discard(uint64_t flags);
 
 	/// Blit 2D texture region between two 2D textures.
 	///

include/bgfx/c99/bgfx.h

@@ -2670,10 +2670,12 @@ BGFX_C_API void bgfx_encoder_dispatch(bgfx_encoder_t* _this, bgfx_view_id_t _id,
 BGFX_C_API void bgfx_encoder_dispatch_indirect(bgfx_encoder_t* _this, bgfx_view_id_t _id, bgfx_program_handle_t _program, bgfx_indirect_buffer_handle_t _indirectHandle, uint16_t _start, uint16_t _num);
 
 /**
- * Discard all previously set state for draw or compute call.
+ * Discard previously set state for draw or compute call.
+ *
+ * @param[in] _flags rendering states to discard
  *
  */
-BGFX_C_API void bgfx_encoder_discard(bgfx_encoder_t* _this);
+BGFX_C_API void bgfx_encoder_discard(bgfx_encoder_t* _this, uint64_t _flags);
 
 /**
  * Blit 2D texture region between two 2D textures.
@@ -3186,10 +3188,12 @@ BGFX_C_API void bgfx_dispatch(bgfx_view_id_t _id, bgfx_program_handle_t _program
 BGFX_C_API void bgfx_dispatch_indirect(bgfx_view_id_t _id, bgfx_program_handle_t _program, bgfx_indirect_buffer_handle_t _indirectHandle, uint16_t _start, uint16_t _num);
 
 /**
- * Discard all previously set state for draw or compute call.
+ * Discard previously set state for draw or compute call.
+ *
+ * @param[in] _flags rendering states to discard
  *
  */
-BGFX_C_API void bgfx_discard(void);
+BGFX_C_API void bgfx_discard(uint64_t _flags);
 
 /**
  * Blit 2D texture region between two 2D textures.
@@ -3554,7 +3558,7 @@ struct bgfx_interface_vtbl
     void (*encoder_set_image)(bgfx_encoder_t* _this, uint8_t _stage, bgfx_texture_handle_t _handle, uint8_t _mip, bgfx_access_t _access, bgfx_texture_format_t _format);
     void (*encoder_dispatch)(bgfx_encoder_t* _this, bgfx_view_id_t _id, bgfx_program_handle_t _program, uint32_t _numX, uint32_t _numY, uint32_t _numZ);
     void (*encoder_dispatch_indirect)(bgfx_encoder_t* _this, bgfx_view_id_t _id, bgfx_program_handle_t _program, bgfx_indirect_buffer_handle_t _indirectHandle, uint16_t _start, uint16_t _num);
-    void (*encoder_discard)(bgfx_encoder_t* _this);
+    void (*encoder_discard)(bgfx_encoder_t* _this, uint64_t _flags);
     void (*encoder_blit)(bgfx_encoder_t* _this, bgfx_view_id_t _id, bgfx_texture_handle_t _dst, uint8_t _dstMip, uint16_t _dstX, uint16_t _dstY, uint16_t _dstZ, bgfx_texture_handle_t _src, uint8_t _srcMip, uint16_t _srcX, uint16_t _srcY, uint16_t _srcZ, uint16_t _width, uint16_t _height, uint16_t _depth);
     void (*request_screen_shot)(bgfx_frame_buffer_handle_t _handle, const char* _filePath);
     bgfx_render_frame_t (*render_frame)(int32_t _msecs);
@@ -3596,7 +3600,7 @@ struct bgfx_interface_vtbl
     void (*set_image)(uint8_t _stage, bgfx_texture_handle_t _handle, uint8_t _mip, bgfx_access_t _access, bgfx_texture_format_t _format);
     void (*dispatch)(bgfx_view_id_t _id, bgfx_program_handle_t _program, uint32_t _numX, uint32_t _numY, uint32_t _numZ);
     void (*dispatch_indirect)(bgfx_view_id_t _id, bgfx_program_handle_t _program, bgfx_indirect_buffer_handle_t _indirectHandle, uint16_t _start, uint16_t _num);
-    void (*discard)(void);
+    void (*discard)(uint64_t _flags);
     void (*blit)(bgfx_view_id_t _id, bgfx_texture_handle_t _dst, uint8_t _dstMip, uint16_t _dstX, uint16_t _dstY, uint16_t _dstZ, bgfx_texture_handle_t _src, uint8_t _srcMip, uint16_t _srcX, uint16_t _srcY, uint16_t _srcZ, uint16_t _width, uint16_t _height, uint16_t _depth);
 };
 

include/bgfx/defines.h

@@ -99,6 +99,19 @@
 #define BGFX_STATE_CULL_SHIFT               36                           //!< Culling mode bit shift
 #define BGFX_STATE_CULL_MASK                UINT64_C(0x0000003000000000) //!< Culling mode bit mask
 
+/**
+ * Rendering state discard. When state is preserved in submit, rendering states can be discarded on a finer grain.
+ *
+ */
+#define BGFX_STATE_DISCARD_INDEX_BUFFER     UINT64_C(0x0000000000000001) //!< Discard only Index Buffer
+#define BGFX_STATE_DISCARD_VERTEX_STREAMS   UINT64_C(0x0000000000000002) //!< Discard only Vertex Streams
+#define BGFX_STATE_DISCARD_TEXTURE_SAMPLERS UINT64_C(0x0000000000000003) //!< Discard only texture samplers
+#define BGFX_STATE_DISCARD_COMPUTE          UINT64_C(0x0000000000000004) //!< Discard only Compute shader related state
+#define BGFX_STATE_DISCARD_STATE            UINT64_C(0x0000000000000005) //!< Discard only state
+#define BGFX_STATE_DISCARD_ALL              UINT64_C(0xffffffffffffffff) //!< Discard every rendering states
+#define BGFX_STATE_DISCARD_SHIFT            0                            //!< Discard flags bit shift
+#define BGFX_STATE_DISCARD_MASK             UINT64_C(0x0000000000000007) //!< Discard flags bit mask
+
 /**
  * Alpha reference value.
  *

scripts/bgfx.idl

@@ -83,6 +83,16 @@ flag.StateCull { bits = 64, shift = 36, range = 2, base = 1, desc = "Culling mod
 	.Ccw --- Cull counter-clockwise triangles.
 	()
 
+--- Rendering state discard. When state is preserved in submit, rendering states can be discarded on a finer grain.
+flag.StateDiscard { bits = 64, shift = 0, range = 3, base = 1, desc = "Discard flags" }
+	.IndexBuffer                --- Discard only Index Buffer
+	.VertexStreams              --- Discard only Vertex Streams
+    .TextureSamplers            --- Discard only texture samplers
+    .Compute                    --- Discard only Compute shader related state
+    .State                      --- Discard only state
+	.All (0xffffffffffffffff)   --- Discard every rendering states
+	()
+
 --- Alpha reference value.
 flag.StateAlphaRef { bits = 64, shift = 40, range = 8, desc = "Alpha reference", "helper" }
 
@@ -2421,11 +2431,11 @@ func.Encoder.dispatch
 	.id      "ViewId"        --- View id.
 	.program "ProgramHandle" --- Compute program.
 	.numX    "uint32_t"      --- Number of groups X.
-	 { deafult = 1 }
+	 { default = 1 }
 	.numY    "uint32_t"      --- Number of groups Y.
-	 { deafult = 1 }
+	 { default = 1 }
 	.numZ    "uint32_t"      --- Number of groups Z.
-	 { deafult = 1 }
+	 { default = 1 }
 
 --- Dispatch compute indirect.
 func.Encoder.dispatch { cname = "dispatch_indirect" }
@@ -2434,13 +2444,14 @@ func.Encoder.dispatch { cname = "dispatch_indirect" }
 	.program        "ProgramHandle"        --- Compute program.
 	.indirectHandle "IndirectBufferHandle" --- Indirect buffer.
 	.start          "uint16_t"             --- First element in indirect buffer.
-	 { deafult = 0 }
+	 { default = 0 }
 	.num            "uint16_t"             --- Number of dispatches.
-	 { deafult = 1 }
+	 { default = 1 }
 
---- Discard all previously set state for draw or compute call.
+--- Discard previously set state for draw or compute call.
 func.Encoder.discard
 	"void"
+	.flags   "uint64_t"     --- rendering states to discard
 
 --- Blit 2D texture region between two 2D textures.
 ---
@@ -2931,11 +2942,11 @@ func.dispatch
 	.id      "ViewId"        --- View id.
 	.program "ProgramHandle" --- Compute program.
 	.numX    "uint32_t"      --- Number of groups X.
-	 { deafult = 1 }
+	 { default = 1 }
 	.numY    "uint32_t"      --- Number of groups Y.
-	 { deafult = 1 }
+	 { default = 1 }
 	.numZ    "uint32_t"      --- Number of groups Z.
-	 { deafult = 1 }
+	 { default = 1 }
 
 --- Dispatch compute indirect.
 func.dispatch { cname = "dispatch_indirect" }
@@ -2944,13 +2955,14 @@ func.dispatch { cname = "dispatch_indirect" }
 	.program        "ProgramHandle"        --- Compute program.
 	.indirectHandle "IndirectBufferHandle" --- Indirect buffer.
 	.start          "uint16_t"             --- First element in indirect buffer.
-	 { deafult = 0 }
+	 { default = 0 }
 	.num            "uint16_t"             --- Number of dispatches.
-	 { deafult = 1 }
+	 { default = 1 }
 
---- Discard all previously set state for draw or compute call.
+--- Discard previously set state for draw or compute call.
 func.discard
 	"void"
+	.flags   "uint64_t"     --- rendering states to discard
 
 --- Blit 2D texture region between two 2D textures.
 ---

src/bgfx.cpp

@@ -1184,14 +1184,14 @@ namespace bgfx
 
 		if (m_discard)
 		{
-			discard();
+			discard(BGFX_STATE_DISCARD_ALL);
 			return;
 		}
 
 		if (0 == m_draw.m_numVertices
 		&&  0 == m_draw.m_numIndices)
 		{
-			discard();
+			discard(BGFX_STATE_DISCARD_ALL);
 			++m_numDropped;
 			return;
 		}
@@ -1199,7 +1199,7 @@ namespace bgfx
 		const uint32_t renderItemIdx = bx::atomicFetchAndAddsat<uint32_t>(&m_frame->m_numRenderItems, 1, BGFX_CONFIG_MAX_DRAW_CALLS);
 		if (BGFX_CONFIG_MAX_DRAW_CALLS-1 <= renderItemIdx)
 		{
-			discard();
+			discard(BGFX_STATE_DISCARD_ALL);
 			++m_numDropped;
 			return;
 		}
@@ -1266,8 +1266,8 @@ namespace bgfx
 
 		if (!_preserveState)
 		{
-			m_draw.clear();
-			m_bind.clear();
+			m_draw.clear(BGFX_STATE_DISCARD_ALL);
+			m_bind.clear(BGFX_STATE_DISCARD_ALL);
 			m_uniformBegin = m_uniformEnd;
 		}
 	}
@@ -1281,14 +1281,14 @@ namespace bgfx
 
 		if (m_discard)
 		{
-			discard();
+			discard(BGFX_STATE_DISCARD_ALL);
 			return;
 		}
 
 		const uint32_t renderItemIdx = bx::atomicFetchAndAddsat<uint32_t>(&m_frame->m_numRenderItems, 1, BGFX_CONFIG_MAX_DRAW_CALLS);
 		if (BGFX_CONFIG_MAX_DRAW_CALLS-1 <= renderItemIdx)
 		{
-			discard();
+			discard(BGFX_STATE_DISCARD_ALL);
 			++m_numDropped;
 			return;
 		}
@@ -1319,8 +1319,8 @@ namespace bgfx
 		m_frame->m_renderItem[renderItemIdx].compute = m_compute;
 		m_frame->m_renderItemBind[renderItemIdx]     = m_bind;
 
-		m_compute.clear();
-		m_bind.clear();
+		m_compute.clear(BGFX_STATE_DISCARD_ALL);
+		m_bind.clear(BGFX_STATE_DISCARD_ALL);
 		m_uniformBegin = m_uniformEnd;
 	}
 
@@ -3780,9 +3780,9 @@ namespace bgfx
 		BGFX_ENCODER(dispatch(_id, _program, _indirectHandle, _start, _num) );
 	}
 
-	void Encoder::discard()
+	void Encoder::discard(uint64_t flags)
 	{
-		BGFX_ENCODER(discard() );
+		BGFX_ENCODER(discard(flags) );
 	}
 
 	void Encoder::blit(ViewId _id, TextureHandle _dst, uint16_t _dstX, uint16_t _dstY, TextureHandle _src, uint16_t _srcX, uint16_t _srcY, uint16_t _width, uint16_t _height)
@@ -4992,10 +4992,10 @@ namespace bgfx
 		s_ctx->m_encoder0->dispatch(_id, _handle, _indirectHandle, _start, _num);
 	}
 
-	void discard()
+	void discard(uint64_t flags)
 	{
 		BGFX_CHECK_API_THREAD();
-		s_ctx->m_encoder0->discard();
+		s_ctx->m_encoder0->discard(flags);
 	}
 
 	void blit(ViewId _id, TextureHandle _dst, uint16_t _dstX, uint16_t _dstY, TextureHandle _src, uint16_t _srcX, uint16_t _srcY, uint16_t _width, uint16_t _height)

src/bgfx.idl.inl

@@ -912,10 +912,10 @@ BGFX_C_API void bgfx_encoder_dispatch_indirect(bgfx_encoder_t* _this, bgfx_view_
 	This->dispatch((bgfx::ViewId)_id, program.cpp, indirectHandle.cpp, _start, _num);
 }
 
-BGFX_C_API void bgfx_encoder_discard(bgfx_encoder_t* _this)
+BGFX_C_API void bgfx_encoder_discard(bgfx_encoder_t* _this, uint64_t _flags)
 {
 	bgfx::Encoder* This = (bgfx::Encoder*)_this;
-	This->discard();
+	This->discard(_flags);
 }
 
 BGFX_C_API void bgfx_encoder_blit(bgfx_encoder_t* _this, bgfx_view_id_t _id, bgfx_texture_handle_t _dst, uint8_t _dstMip, uint16_t _dstX, uint16_t _dstY, uint16_t _dstZ, bgfx_texture_handle_t _src, uint8_t _srcMip, uint16_t _srcX, uint16_t _srcY, uint16_t _srcZ, uint16_t _width, uint16_t _height, uint16_t _depth)
@@ -1154,9 +1154,9 @@ BGFX_C_API void bgfx_dispatch_indirect(bgfx_view_id_t _id, bgfx_program_handle_t
 	bgfx::dispatch((bgfx::ViewId)_id, program.cpp, indirectHandle.cpp, _start, _num);
 }
 
-BGFX_C_API void bgfx_discard(void)
+BGFX_C_API void bgfx_discard(uint64_t _flags)
 {
-	bgfx::discard();
+	bgfx::discard(_flags);
 }
 
 BGFX_C_API void bgfx_blit(bgfx_view_id_t _id, bgfx_texture_handle_t _dst, uint8_t _dstMip, uint16_t _dstX, uint16_t _dstY, uint16_t _dstZ, bgfx_texture_handle_t _src, uint8_t _srcMip, uint16_t _srcX, uint16_t _srcY, uint16_t _srcZ, uint16_t _width, uint16_t _height, uint16_t _depth)

src/bgfx_p.h

@@ -1543,14 +1543,17 @@ constexpr uint64_t kSortKeyComputeProgramMask  = uint64_t(BGFX_CONFIG_MAX_PROGRA
 
 	BX_ALIGN_DECL_CACHE_LINE(struct) RenderBind
 	{
-		void clear()
+		void clear(uint64_t flags)
 		{
-			for (uint32_t ii = 0; ii < BGFX_CONFIG_MAX_TEXTURE_SAMPLERS; ++ii)
+			if (flags & BGFX_STATE_DISCARD_TEXTURE_SAMPLERS)
 			{
-				Binding& bind = m_bind[ii];
-				bind.m_idx = kInvalidHandle;
-				bind.m_type = 0;
-				bind.m_samplerFlags = 0;
+				for (uint32_t ii = 0; ii < BGFX_CONFIG_MAX_TEXTURE_SAMPLERS; ++ii)
+				{
+					Binding& bind = m_bind[ii];
+					bind.m_idx = kInvalidHandle;
+					bind.m_type = 0;
+					bind.m_samplerFlags = 0;
+				}
 			}
 		};
 
@@ -1559,32 +1562,42 @@ constexpr uint64_t kSortKeyComputeProgramMask  = uint64_t(BGFX_CONFIG_MAX_PROGRA
 
 	BX_ALIGN_DECL_CACHE_LINE(struct) RenderDraw
 	{
-		void clear()
+		void clear(uint64_t flags)
 		{
-			m_uniformBegin = 0;
-			m_uniformEnd   = 0;
-			m_stateFlags   = BGFX_STATE_DEFAULT;
-			m_stencil      = packStencil(BGFX_STENCIL_DEFAULT, BGFX_STENCIL_DEFAULT);
-			m_rgba         = 0;
-			m_startMatrix  = 0;
-			m_startIndex   = 0;
-			m_numIndices   = UINT32_MAX;
-			m_numVertices  = UINT32_MAX;
-			m_instanceDataOffset = 0;
-			m_instanceDataStride = 0;
-			m_numInstances       = 1;
-			m_startIndirect = 0;
-			m_numIndirect   = UINT16_MAX;
-			m_numMatrices   = 1;
-			m_submitFlags   = 0;
-			m_scissor       = UINT16_MAX;
-			m_streamMask    = 0;
-			m_stream[0].clear();
-			m_indexBuffer.idx        = kInvalidHandle;
-			m_instanceDataBuffer.idx = kInvalidHandle;
-			m_indirectBuffer.idx     = kInvalidHandle;
-			m_occlusionQuery.idx     = kInvalidHandle;
-			m_uniformIdx = UINT8_MAX;
+			if (flags & BGFX_STATE_DISCARD_STATE)
+			{
+				m_uniformBegin = 0;
+				m_uniformEnd   = 0;
+				m_stateFlags   = BGFX_STATE_DEFAULT;
+				m_stencil      = packStencil(BGFX_STENCIL_DEFAULT, BGFX_STENCIL_DEFAULT);
+				m_rgba         = 0;
+				m_startMatrix  = 0;
+				m_startIndex   = 0;
+				m_numIndices   = UINT32_MAX;
+				m_numVertices  = UINT32_MAX;
+				m_instanceDataOffset = 0;
+				m_instanceDataStride = 0;
+				m_numInstances       = 1;
+				m_startIndirect = 0;
+				m_numIndirect   = UINT16_MAX;
+				m_numMatrices   = 1;
+				m_submitFlags   = 0;
+				m_scissor       = UINT16_MAX;
+
+				m_instanceDataBuffer.idx = kInvalidHandle;
+				m_indirectBuffer.idx     = kInvalidHandle;
+				m_occlusionQuery.idx     = kInvalidHandle;
+				m_uniformIdx = UINT8_MAX;
+			}
+			if (flags & BGFX_STATE_DISCARD_VERTEX_STREAMS)
+			{
+				m_streamMask = 0;
+				m_stream[0].clear();
+			}
+			if (flags & BGFX_STATE_DISCARD_INDEX_BUFFER)
+			{
+				m_indexBuffer.idx = kInvalidHandle;
+			}
 		}
 
 		bool setStreamBit(uint8_t _stream, VertexBufferHandle _handle)
@@ -1625,21 +1638,24 @@ constexpr uint64_t kSortKeyComputeProgramMask  = uint64_t(BGFX_CONFIG_MAX_PROGRA
 
 	BX_ALIGN_DECL_CACHE_LINE(struct) RenderCompute
 	{
-		void clear()
+		void clear(uint64_t flags)
 		{
-			m_uniformBegin = 0;
-			m_uniformEnd   = 0;
-			m_startMatrix  = 0;
-			m_numX         = 0;
-			m_numY         = 0;
-			m_numZ         = 0;
-			m_numMatrices  = 0;
-			m_submitFlags  = 0;
-			m_uniformIdx   = UINT8_MAX;
+			if (flags & BGFX_STATE_DISCARD_COMPUTE)
+			{
+				m_uniformBegin = 0;
+				m_uniformEnd   = 0;
+				m_startMatrix  = 0;
+				m_numX         = 0;
+				m_numY         = 0;
+				m_numZ         = 0;
+				m_numMatrices  = 0;
+				m_submitFlags  = 0;
+				m_uniformIdx   = UINT8_MAX;
 
-			m_indirectBuffer.idx = kInvalidHandle;
-			m_startIndirect      = 0;
-			m_numIndirect        = UINT16_MAX;
+				m_indirectBuffer.idx = kInvalidHandle;
+				m_startIndirect      = 0;
+				m_numIndirect        = UINT16_MAX;
+			}
 		}
 
 		uint32_t m_uniformBegin;
@@ -2183,7 +2199,7 @@ constexpr uint64_t kSortKeyComputeProgramMask  = uint64_t(BGFX_CONFIG_MAX_PROGRA
 	{
 		EncoderImpl()
 		{
-			discard();
+			discard(BGFX_STATE_DISCARD_ALL);
 		}
 
 		void begin(Frame* _frame, uint8_t _idx)
@@ -2478,7 +2494,7 @@ constexpr uint64_t kSortKeyComputeProgramMask  = uint64_t(BGFX_CONFIG_MAX_PROGRA
 			bind.m_mip    = _mip;
 		}
 
-		void discard()
+		void discard(uint64_t flags)
 		{
 			if (BX_ENABLED(BGFX_CONFIG_DEBUG_UNIFORM) )
 			{
@@ -2486,9 +2502,9 @@ constexpr uint64_t kSortKeyComputeProgramMask  = uint64_t(BGFX_CONFIG_MAX_PROGRA
 			}
 
 			m_discard = false;
-			m_draw.clear();
-			m_compute.clear();
-			m_bind.clear();
+			m_draw.clear(flags);
+			m_compute.clear(flags);
+			m_bind.clear(flags);
 		}
 
 		void submit(ViewId _id, ProgramHandle _program, OcclusionQueryHandle _occlusionQuery, uint32_t _depth, bool _preserveState);

src/renderer_d3d11.cpp

@@ -5309,12 +5309,12 @@ namespace bgfx { namespace d3d11
 		_render->sort();
 
 		RenderDraw currentState;
-		currentState.clear();
+		currentState.clear(BGFX_STATE_DISCARD_ALL);
 		currentState.m_stateFlags = BGFX_STATE_NONE;
 		currentState.m_stencil = packStencil(BGFX_STENCIL_NONE, BGFX_STENCIL_NONE);
 
 		RenderBind currentBind;
-		currentBind.clear();
+		currentBind.clear(BGFX_STATE_DISCARD_ALL);
 
 		static ViewState viewState;
 		viewState.reset(_render);
@@ -5617,9 +5617,9 @@ namespace bgfx { namespace d3d11
 					{
 						if (resetState)
 						{
-							currentState.clear();
+							currentState.clear(BGFX_STATE_DISCARD_ALL);
 							currentState.m_scissor = !draw.m_scissor;
-							currentBind.clear();
+							currentBind.clear(BGFX_STATE_DISCARD_ALL);
 						}
 
 						continue;
@@ -5640,14 +5640,14 @@ namespace bgfx { namespace d3d11
 				{
 					wasCompute = false;
 
-					currentState.clear();
+					currentState.clear(BGFX_STATE_DISCARD_ALL);
 					currentState.m_scissor = !draw.m_scissor;
 					changedFlags = BGFX_STATE_MASK;
 					changedStencil = packStencil(BGFX_STENCIL_MASK, BGFX_STENCIL_MASK);
 					currentState.m_stateFlags = newFlags;
 					currentState.m_stencil    = newStencil;
 
-					currentBind.clear();
+					currentBind.clear(BGFX_STATE_DISCARD_ALL);
 
 					setBlendState(newFlags);
 					setDepthStencilState(newFlags, packStencil(BGFX_STENCIL_DEFAULT, BGFX_STENCIL_DEFAULT) );

src/renderer_d3d12.cpp

@@ -5753,12 +5753,12 @@ namespace bgfx { namespace d3d12
 		_render->sort();
 
 		RenderDraw currentState;
-		currentState.clear();
+		currentState.clear(BGFX_STATE_DISCARD_ALL);
 		currentState.m_stateFlags = BGFX_STATE_NONE;
 		currentState.m_stencil    = packStencil(BGFX_STENCIL_NONE, BGFX_STENCIL_NONE);
 
 		RenderBind currentBind;
-		currentBind.clear();
+		currentBind.clear(BGFX_STATE_DISCARD_ALL);
 
 		static ViewState viewState;
 		viewState.reset(_render);
@@ -6174,9 +6174,9 @@ namespace bgfx { namespace d3d12
 					{
 						if (resetState)
 						{
-							currentState.clear();
+							currentState.clear(BGFX_STATE_DISCARD_ALL);
 							currentState.m_scissor = !draw.m_scissor;
-							currentBind.clear();
+							currentBind.clear(BGFX_STATE_DISCARD_ALL);
 							commandListChanged = true;
 						}
 
@@ -6196,14 +6196,14 @@ namespace bgfx { namespace d3d12
 				{
 					wasCompute = false;
 
-					currentState.clear();
+					currentState.clear(BGFX_STATE_DISCARD_ALL);
 					currentState.m_scissor = !draw.m_scissor;
 					changedFlags = BGFX_STATE_MASK;
 					changedStencil = packStencil(BGFX_STENCIL_MASK, BGFX_STENCIL_MASK);
 					currentState.m_stateFlags = newFlags;
 					currentState.m_stencil    = newStencil;
 
-					currentBind.clear();
+					currentBind.clear(BGFX_STATE_DISCARD_ALL);
 
 					commandListChanged = true;
 				}
@@ -6223,14 +6223,14 @@ namespace bgfx { namespace d3d12
 					currentBindHash        = 0;
 					currentSamplerStateIdx = kInvalidHandle;
 					currentProgram         = BGFX_INVALID_HANDLE;
-					currentState.clear();
+					currentState.clear(BGFX_STATE_DISCARD_ALL);
 					currentState.m_scissor = !draw.m_scissor;
 					changedFlags = BGFX_STATE_MASK;
 					changedStencil = packStencil(BGFX_STENCIL_MASK, BGFX_STENCIL_MASK);
 					currentState.m_stateFlags = newFlags;
 					currentState.m_stencil    = newStencil;
 
-					currentBind.clear();
+					currentBind.clear(BGFX_STATE_DISCARD_ALL);
 
 					const uint64_t pt = newFlags&BGFX_STATE_PT_MASK;
 					primIndex = uint8_t(pt>>BGFX_STATE_PT_SHIFT);

src/renderer_d3d9.cpp

@@ -3746,12 +3746,12 @@ namespace bgfx { namespace d3d9
 		_render->sort();
 
 		RenderDraw currentState;
-		currentState.clear();
+		currentState.clear(BGFX_STATE_DISCARD_ALL);
 		currentState.m_stateFlags = BGFX_STATE_NONE;
 		currentState.m_stencil    = packStencil(BGFX_STENCIL_NONE, BGFX_STENCIL_NONE);
 
 		RenderBind currentBind;
-		currentBind.clear();
+		currentBind.clear(BGFX_STATE_DISCARD_ALL);
 
 		static ViewState viewState;
 		viewState.reset(_render);
@@ -3839,7 +3839,7 @@ namespace bgfx { namespace d3d9
 
 				if (key.m_view != view)
 				{
-					currentState.clear();
+					currentState.clear(BGFX_STATE_DISCARD_ALL);
 					currentState.m_scissor = !draw.m_scissor;
 					changedFlags = BGFX_STATE_MASK;
 					changedStencil = packStencil(BGFX_STENCIL_MASK, BGFX_STENCIL_MASK);

src/renderer_gl.cpp

@@ -6482,12 +6482,12 @@ BX_TRACE("%d, %d, %d, %s", _array, _srgb, _mipAutogen, getName(_format) );
 		_render->sort();
 
 		RenderDraw currentState;
-		currentState.clear();
+		currentState.clear(BGFX_STATE_DISCARD_ALL);
 		currentState.m_stateFlags = BGFX_STATE_NONE;
 		currentState.m_stencil    = packStencil(BGFX_STENCIL_NONE, BGFX_STENCIL_NONE);
 
 		RenderBind currentBind;
-		currentBind.clear();
+		currentBind.clear(BGFX_STATE_DISCARD_ALL);
 
 		static ViewState viewState;
 		viewState.reset(_render);
@@ -6769,9 +6769,9 @@ BX_TRACE("%d, %d, %d, %s", _array, _srgb, _mipAutogen, getName(_format) );
 					{
 						if (resetState)
 						{
-							currentState.clear();
+							currentState.clear(BGFX_STATE_DISCARD_ALL);
 							currentState.m_scissor = !draw.m_scissor;
-							currentBind.clear();
+							currentBind.clear(BGFX_STATE_DISCARD_ALL);
 						}
 
 						continue;
@@ -6788,14 +6788,14 @@ BX_TRACE("%d, %d, %d, %s", _array, _srgb, _mipAutogen, getName(_format) );
 
 				if (resetState)
 				{
-					currentState.clear();
+					currentState.clear(BGFX_STATE_DISCARD_ALL);
 					currentState.m_scissor = !draw.m_scissor;
 					changedFlags   = BGFX_STATE_MASK;
 					changedStencil = packStencil(BGFX_STENCIL_MASK, BGFX_STENCIL_MASK);
 					currentState.m_stateFlags = newFlags;
 					currentState.m_stencil    = newStencil;
 
-					currentBind.clear();
+					currentBind.clear(BGFX_STATE_DISCARD_ALL);
 				}
 
 				uint16_t scissor = draw.m_scissor;

src/renderer_mtl.mm

@@ -3687,12 +3687,12 @@ namespace bgfx { namespace mtl
 		_render->sort();
 
 		RenderDraw currentState;
-		currentState.clear();
+		currentState.clear(BGFX_STATE_DISCARD_ALL);
 		currentState.m_stateFlags = BGFX_STATE_NONE;
 		currentState.m_stencil    = packStencil(BGFX_STENCIL_NONE, BGFX_STENCIL_NONE);
 
 		RenderBind currentBind;
-		currentBind.clear();
+		currentBind.clear(BGFX_STATE_DISCARD_ALL);
 
 		static ViewState viewState;
 		viewState.reset(_render);
@@ -4136,9 +4136,9 @@ namespace bgfx { namespace mtl
 					{
 						if (resetState)
 						{
-							currentState.clear();
+							currentState.clear(BGFX_STATE_DISCARD_ALL);
 							currentState.m_scissor = !draw.m_scissor;
-							currentBind.clear();
+							currentBind.clear(BGFX_STATE_DISCARD_ALL);
 						}
 
 						continue;
@@ -4155,14 +4155,14 @@ namespace bgfx { namespace mtl
 
 				if (resetState)
 				{
-					currentState.clear();
+					currentState.clear(BGFX_STATE_DISCARD_ALL);
 					currentState.m_scissor = !draw.m_scissor;
 					changedFlags = BGFX_STATE_MASK;
 					changedStencil = packStencil(BGFX_STENCIL_MASK, BGFX_STENCIL_MASK);
 					currentState.m_stateFlags = newFlags;
 					currentState.m_stencil    = newStencil;
 
-					currentBind.clear();
+					currentBind.clear(BGFX_STATE_DISCARD_ALL);
 
 					currentProgram = BGFX_INVALID_HANDLE;
 					setDepthStencilState(newFlags, packStencil(BGFX_STENCIL_DEFAULT, BGFX_STENCIL_DEFAULT) );

src/renderer_vk.cpp

@@ -5733,7 +5733,7 @@ VK_DESTROY
 		_render->sort();
 
 		RenderDraw currentState;
-		currentState.clear();
+		currentState.clear(BGFX_STATE_DISCARD_ALL);
 		currentState.m_stateFlags = BGFX_STATE_NONE;
 		currentState.m_stencil    = packStencil(BGFX_STENCIL_NONE, BGFX_STENCIL_NONE);
 
@@ -6138,7 +6138,7 @@ VK_DESTROY
 					currentDslHash         = 0;
 					currentSamplerStateIdx = kInvalidHandle;
 					currentProgram         = BGFX_INVALID_HANDLE;
-					currentState.clear();
+					currentState.clear(BGFX_STATE_DISCARD_ALL);
 					currentState.m_scissor = !draw.m_scissor;
 					changedFlags = BGFX_STATE_MASK;
 					changedStencil = packStencil(BGFX_STENCIL_MASK, BGFX_STENCIL_MASK);