-bgfx: Adjusted per-pass blending handling - fixes MT07586 and MT07587. (#10747) [Ryan Holtz]

bgfx/effects/gui_multiply.json

@@ -10,9 +10,7 @@
 	"blend": {
 		"equation": "add",
 		"srcColor": "dstcolor",
-		"dstColor": "0",
-		"srcAlpha": "dstalpha",
-		"dstAlpha": "0"
+		"dstColor": "0"
 	},
 	"depth": {
 		"function": "always"

bgfx/effects/misc/blit.json

@@ -21,10 +21,10 @@
 		// defaults (dstColor, dstAlpha): "0"
 		//
 		// "zero", "one", "invsrccolor", "invdstcolor", "invsrcalpha", and "invdstalpha" are provided as aliases for "0", "1", "1-srccolor", "1-dstcolor", "1-srcalpha", and "1-dstalpha"
-		"srcColor": "srcalpha",
-		"dstColor": "1-srcalpha",
-		"srcAlpha": "srcalpha",
-		"dstAlpha": "1-srcalpha"
+		"srcColor": "1",
+		"dstColor": "0",
+		"srcAlpha": "1",
+		"dstAlpha": "0"
 	},
 
 	// depth (required): The depth state for this effect.

bgfx/effects/misc/blit_alpha.json

@@ -0,0 +1,121 @@
+// license:BSD-3-Clause
+// copyright-holders:Ryan Holtz
+//============================================================
+//
+//  blit_alpha.json: A simple texture-to-target copy.
+//
+//============================================================
+{
+	// blend (required): The blend state for this effect.
+	"blend": {
+		// equation (optional): What equation to perform on the source and destination blend values.
+		// values: "add", "sub", "revSub", "min", "max"
+		// default: "add"
+		//
+		// "subtract" and "revSubtract" are provided as aliases for "sub" and "revSub"
+		"equation": "add",
+
+		// blend function parameters (optional): What factors to use in the blend function when calculating the final pixel.
+		// values: "0", "1", "srccolor", "1-srccolor", "dstcolor", "1-dstcolor", "srcalpha", "1-srcalpha", "dstalpha", "1-dstalpha"
+		// defaults (srcColor, srcAlpha): "1"
+		// defaults (dstColor, dstAlpha): "0"
+		//
+		// "zero", "one", "invsrccolor", "invdstcolor", "invsrcalpha", and "invdstalpha" are provided as aliases for "0", "1", "1-srccolor", "1-dstcolor", "1-srcalpha", and "1-dstalpha"
+		"srcColor": "srcalpha",
+		"dstColor": "1-srcalpha",
+		"srcAlpha": "srcalpha",
+		"dstAlpha": "1-srcalpha"
+	},
+
+	// depth (required): The depth state for this effect.
+	"depth": {
+		// function (optional): The depth function to use when drawing.
+		// values: "never", "less", "equal", "lequal", "greater", "notequal", "gequal", "always"
+		// default: "always"
+		"function": "always",
+
+		// writeenable (optional): Whether to store Z-buffer data.
+		// values: true, false
+		// default: false
+		"writeenable": false
+	},
+
+	// cull (required): The cull mode for this effect.
+	"cull": {
+		// mode (optional): What winding, if any, to cull.
+		// values: "none", "cw", "ccw"
+		// default: "ccw"
+		//
+		// "clockwise" and "counterclockwise" are provided as aliases for "cw" and "ccw"
+		"mode": "none"
+	},
+
+	// write (required): Write enable for color and alpha channels.
+	"write": {
+		// rgb (optional): Whether to store color data when drawing.
+		// values: true, false
+		// default: false
+		"rgb": true,
+
+		// alpha (optional): Whether to store alpha data when drawing.
+		// values: true, false
+		// default: false
+		"alpha": true
+	},
+
+	// vertex (required): The vertex shader to use when drawing.
+	// value: A string containing the path and name of a shader file to use, minus the extension.
+	"vertex": "chains/misc/vs_blit",
+
+	// pixel/fragment (required): The pixel or fragment shader to use when drawing.
+	// value: A string containing the path and name of a shader file to use, minus the extension.
+	"fragment": "chains/misc/fs_blit",
+
+	// uniforms (required): The list of uniforms for this effect. Can be empty, but must exist.
+	"uniforms": [
+		{
+			// name (required): The name of the uniform, as used in either the vertex or pixel/fragment shader.
+			// value: A string containing the name of the uniform as described above.
+			//
+			// NOTE: Some names correspond to special values that will be automatically filled by the BGFX
+			//       code if they are used by the shader. These names are:
+			//           "u_screen_dims"
+			//              The dimensions of the first texture input if present, otherwise the dimensions of the output window.
+			//              Valid values: xy
+			//           "u_inv_screen_dims"
+			//              The reciprocal of u_screen_dims.
+			//              Valid values: xy
+			//           "u_source_dims"
+			//              The size, in pixels, of the screen texture incoming to the chain.
+			//              Valid values: xy
+			//           "u_rotation_type"
+			//              This screen's rotation type. 0 if ROT0, 1 if ROT90, 2 if ROT180, 3 of ROT270.
+			//              Valid values: x
+			//           "u_swap_xy"
+			//              Whether this screen is swapped on the X and Y axes. 1 if true, 0 if false.
+			//              Valid values: x
+			//           "u_quad_dims"
+			//              The dimensions, in pixels, occupied by this one screen primitive itself in the output window.
+			//              Valid values: xy
+			//           "u_tex_sizeN"
+			//              The dimensions, in pixels, of the texture in input pair N. Starts at 0.
+			//              valid values: xy
+			"name": "s_tex",
+
+			// type (required): The type of the uniform.
+			// values: "int", "vec4", "mat3", "mat4"
+			//
+			// Note: "int" should only be used for samplers.
+			"type": "int",
+
+			// values (required): The array of numbers with which to initialize the uniform.
+			// value: A JSON array containin the correct amount of numbers to initialize a uniform of the
+			//        above-specified type. The following size rules should be followed:
+			//            "int": 1 float
+			//            "vec4": 4 floats
+			//            "mat3": 9 floats
+			//            "mat4": 16 floats
+			"values": [ 1.0 ]
+		}
+	]
+}

bgfx/effects/screen_multiply.json

@@ -11,9 +11,7 @@
 	"blend": {
 		"equation": "add",
 		"srcColor": "dstcolor",
-		"dstColor": "0",
-		"srcAlpha": "dstalpha",
-		"dstAlpha": "0"
+		"dstColor": "0"
 	},
 	"depth": {
 		"function": "always"

src/osd/modules/render/bgfx/blendreader.cpp

@@ -44,8 +44,11 @@ uint64_t blend_reader::read_from_value(const Value& value)
 	uint64_t equation = get_enum_from_value(value, "equation", BGFX_STATE_BLEND_EQUATION_ADD, EQUATION_NAMES, EQUATION_COUNT);
 	uint64_t srccolor = get_enum_from_value(value, "srcColor", BGFX_STATE_BLEND_ONE, FUNCTION_NAMES, FUNCTION_COUNT);
 	uint64_t dstcolor = get_enum_from_value(value, "dstColor", BGFX_STATE_BLEND_ZERO, FUNCTION_NAMES, FUNCTION_COUNT);
-	uint64_t srcalpha = get_enum_from_value(value, "srcAlpha", BGFX_STATE_BLEND_ONE, FUNCTION_NAMES, FUNCTION_COUNT);
-	uint64_t dstalpha = get_enum_from_value(value, "dstAlpha", BGFX_STATE_BLEND_ZERO, FUNCTION_NAMES, FUNCTION_COUNT);
-
-	return BGFX_STATE_BLEND_EQUATION(equation) | BGFX_STATE_BLEND_FUNC_SEPARATE(srccolor, dstcolor, srcalpha, dstalpha);
+	if (value.HasMember("srcAlpha") && value.HasMember("dstAlpha"))
+	{
+		uint64_t srcalpha = get_enum_from_value(value, "srcAlpha", BGFX_STATE_BLEND_ONE, FUNCTION_NAMES, FUNCTION_COUNT);
+		uint64_t dstalpha = get_enum_from_value(value, "dstAlpha", BGFX_STATE_BLEND_ZERO, FUNCTION_NAMES, FUNCTION_COUNT);
+		return BGFX_STATE_BLEND_EQUATION(equation) | BGFX_STATE_BLEND_FUNC_SEPARATE(srccolor, dstcolor, srcalpha, dstalpha);
+	}
+	return BGFX_STATE_BLEND_EQUATION(equation) | BGFX_STATE_BLEND_FUNC(srccolor, dstcolor);
 }

src/osd/modules/render/bgfx/chain.cpp

@@ -108,11 +108,12 @@ void bgfx_chain::process(chain_manager::screen_prim &prim, int view, int screen,
 	}
 
 	int current_view = view;
-	for (bgfx_chain_entry* entry : m_entries)
+	for (size_t i = 0; i < m_entries.size(); i++)
 	{
-		if (!entry->skip())
+		if (!m_entries[i]->skip())
 		{
-			entry->submit(current_view, prim, textures, screen_count, screen_width, screen_height, screen_scale_x, screen_scale_y, screen_offset_x, screen_offset_y, rotation_type, swap_xy, blend, screen);
+			m_entries[i]->submit(current_view, prim, textures, screen_count, screen_width, screen_height, screen_scale_x, screen_scale_y, screen_offset_x, screen_offset_y,
+				rotation_type, swap_xy, i == (m_entries.size() - 1) ? blend : ~0ULL, screen);
 			current_view++;
 		}
 	}

src/osd/modules/render/bgfx/chainmanager.cpp

@@ -65,6 +65,7 @@ chain_manager::chain_manager(running_machine& machine, osd_options& options, tex
 	, m_window_index(window_index)
 	, m_slider_notifier(slider_notifier)
 	, m_screen_count(0)
+	, m_default_chain_index(-1)
 {
 	m_converters.clear();
 	refresh_available_chains();
@@ -87,6 +88,20 @@ void chain_manager::init_texture_converters()
 	m_adjuster = m_effects.get_or_load_effect(m_options, "misc/bcg_adjust");
 }
 
+void chain_manager::get_default_chain_info(std::string &out_chain_name, int32_t &out_chain_index)
+{
+	if (m_default_chain_index == -1)
+	{
+		out_chain_index = CHAIN_NONE;
+		out_chain_name = "";
+		return;
+	}
+
+	out_chain_index = m_default_chain_index;
+	out_chain_name = "default";
+	return;
+}
+
 void chain_manager::refresh_available_chains()
 {
 	m_available_chains.clear();
@@ -94,6 +109,16 @@ void chain_manager::refresh_available_chains()
 
 	const std::string chains_path  = util::string_format("%s" PATH_SEPARATOR "chains", m_options.bgfx_path());
 	find_available_chains(chains_path, "");
+	if (m_default_chain_index == -1)
+	{
+		for (size_t i = 0; i < m_available_chains.size(); i++)
+		{
+			if (m_available_chains[i].m_name == "default")
+			{
+				m_default_chain_index = int32_t(i);
+			}
+		}
+	}
 
 	destroy_unloaded_chains();
 }
@@ -112,8 +137,7 @@ void chain_manager::destroy_unloaded_chains()
 				{
 					delete m_screen_chains[i];
 					m_screen_chains[i] = nullptr;
-					m_chain_names[i] = "";
-					m_current_chain[i] = CHAIN_NONE;
+					get_default_chain_info(m_chain_names[i], m_current_chain[i]);
 					break;
 				}
 			}
@@ -332,7 +356,7 @@ void chain_manager::process_screen_quad(uint32_t view, uint32_t screen, screen_p
 	}
 
 	bgfx_chain* chain = screen_chain(screen);
-	chain->process(prim, view, screen, m_textures, window, bgfx_util::get_blend_state(PRIMFLAG_GET_BLENDMODE(prim.m_flags)));
+	chain->process(prim, view, screen, m_textures, window);
 	view += chain->applicable_passes();
 }
 
@@ -381,8 +405,12 @@ void chain_manager::update_screen_count(uint32_t screen_count)
 		while (m_screen_chains.size() < m_screen_count)
 		{
 			m_screen_chains.push_back(nullptr);
-			m_chain_names.push_back("");
-			m_current_chain.push_back(CHAIN_NONE);
+
+			int32_t chain_index = CHAIN_NONE;
+			std::string chain_name = "";
+			get_default_chain_info(chain_name, chain_index);
+			m_chain_names.push_back(chain_name);
+			m_current_chain.push_back(chain_index);
 		}
 
 		// Ensure we have a screen chain selection slider per screen

src/osd/modules/render/bgfx/chainmanager.h

@@ -102,6 +102,7 @@ private:
 
 	void init_texture_converters();
 
+	void get_default_chain_info(std::string &out_chain_name, int32_t &out_chain_index);
 	void refresh_available_chains();
 	void destroy_unloaded_chains();
 	void find_available_chains(std::string root, std::string path);
@@ -125,6 +126,7 @@ private:
 	uint32_t                    m_window_index;
 	slider_dirty_notifier&      m_slider_notifier;
 	uint32_t                    m_screen_count;
+	int32_t                     m_default_chain_index;
 	std::vector<chain_desc>     m_available_chains;
 	std::vector<bgfx_chain*>    m_screen_chains;
 	std::vector<std::string>    m_chain_names;

src/osd/modules/render/bgfx/effect.cpp

@@ -47,7 +47,8 @@ void bgfx_effect::submit(int view, uint64_t blend)
 	{
 		(uniform_pair.second)->upload();
 	}
-	bgfx::setState(m_state | blend);
+	const uint64_t final_blend = (blend != ~0ULL) ? ((m_state & ~BGFX_STATE_BLEND_MASK) | blend) : m_state;
+	bgfx::setState(final_blend);
 	bgfx::submit(view, m_program_handle);
 }
 

src/osd/modules/render/bgfx/effect.h

@@ -25,7 +25,7 @@ public:
 	bgfx_effect(uint64_t state, bgfx::ShaderHandle vertex_shader, bgfx::ShaderHandle fragment_shader, std::vector<bgfx_uniform*> uniforms);
 	~bgfx_effect();
 
-	void submit(int view, uint64_t blend = 0L);
+	void submit(int view, uint64_t blend = ~0ULL);
 	bgfx_uniform *uniform(std::string name);
 	bool is_valid() { return m_program_handle.idx != bgfx::kInvalidHandle; }
 

src/osd/modules/render/bgfxutil.cpp

@@ -96,7 +96,7 @@ uint64_t bgfx_util::get_blend_state(uint32_t blend)
 		case BLENDMODE_ALPHA:
 			return BGFX_STATE_BLEND_FUNC(BGFX_STATE_BLEND_SRC_ALPHA, BGFX_STATE_BLEND_INV_SRC_ALPHA);
 		case BLENDMODE_RGB_MULTIPLY:
-			return BGFX_STATE_BLEND_FUNC_SEPARATE(BGFX_STATE_BLEND_DST_COLOR, BGFX_STATE_BLEND_ZERO, BGFX_STATE_BLEND_DST_ALPHA, BGFX_STATE_BLEND_ZERO);
+			return BGFX_STATE_BLEND_FUNC(BGFX_STATE_BLEND_DST_COLOR, BGFX_STATE_BLEND_ZERO);
 		case BLENDMODE_ADD:
 			return BGFX_STATE_BLEND_FUNC(BGFX_STATE_BLEND_SRC_ALPHA, BGFX_STATE_BLEND_ONE);
 		default: