sega/sega_beena.cpp: Added basic book page display.

sega_beena_cart.xml: Put page scans in individual data areas.

frontend/mame/luaengine_mem.cpp: Added a raw read function for memory
regions.

plugins/layout: Added bitmap classes to layout sandbox.

docs/source/luascript/ref-mem.rst

@@ -419,6 +419,12 @@ manager.machine.devices[tag]:memregion(tag)
 Methods
 ~~~~~~~
 
+region:read(offs, len)
+    Reads up to the specified length in bytes from the specified offset in the
+    memory region.  The bytes read will be returned as a string.  If the
+    specified length extends beyond the end of the memory region, the returned
+    string will be shorter than requested.  Note that the data will be in host
+    byte order.
 region:read_i{8,16,32,64}(offs)
     Reads a signed integer value of the size in bits from the specified offset
     in the memory region.  The offset is specified in bytes.  Reading beyond the

docs/source/techspecs/layout_script.rst

@@ -484,6 +484,10 @@ providing what’s needed:
   creating :ref:`attotime <luascript-ref-attotime>`, :ref:`bounds
   <luascript-ref-renderbounds>` and :ref:`colour <luascript-ref-rendercolor>`
   objects.
+* ``emu.bitmap_ind8``, ``emu.bitmap_ind16``, ``emu.bitmap_ind32``,
+  ``emu.bitmap_ind64``, ``emu.bitmap_yuy16``, ``emu.bitmap_rgb32`` and
+  ``emu.bitmap_argb32`` objects for creating
+  :ref:`bitmaps <luascript-ref-bitmap>`.
 * ``emu.print_verbose``, ``emu.print_error``, ``emu.print_warning``,
   ``emu.print_info`` and ``emu.print_debug`` functions for diagnostic output.
 * Standard Lua ``tonumber``, ``tostring``, ``pairs`` and ``ipairs`` functions,
@@ -667,3 +671,21 @@ Get item vertical scroll position
     item; larger values pan down.  Call with ``nil`` as the argument to restore
     the default vertical scroll position handler (based on bindings in the
     ``yscroll`` child element).
+
+.. _layscript-events-element:
+
+Layout element events
+~~~~~~~~~~~~~~~~~~~~~
+
+Layout element events apply to an individual visual element definition.
+
+Draw
+    ``element:set_draw_callback(cb)``
+
+    Set callback for additional drawing after the element’s components have been
+    drawn.  This gives the script direct control over the final texture when an
+    element item is drawn.
+
+    The callback is passed two arguments: the element state (an integer) and the
+    32-bit ARGB bitmap at the required size.  The callback must not attempt to
+    resize the bitmap.

plugins/layout/init.lua

@@ -22,6 +22,13 @@ function layout.startplugin()
 				attotime = emu.attotime,
 				render_bounds = emu.render_bounds,
 				render_color = emu.render_color,
+				bitmap_ind8 = emu.bitmap_ind8,
+				bitmap_ind16 = emu.bitmap_ind16,
+				bitmap_ind32 = emu.bitmap_ind32,
+				bitmap_ind64 = emu.bitmap_ind64,
+				bitmap_yuy16 = emu.bitmap_yuy16,
+				bitmap_rgb32 = emu.bitmap_rgb32,
+				bitmap_argb32 = emu.bitmap_argb32,
 				print_verbose = emu.print_verbose,
 				print_error = emu.print_error,
 				print_warning = emu.print_warning,

scripts/src/formats.lua

@@ -1405,6 +1405,18 @@ if opt_tool(FORMATS, "MZ_CAS") then
 	}
 end
 
+--------------------------------------------------
+--
+--@src/lib/formats/nabupc_dsk.h,FORMATS["NABUPC_DSK"] = true
+--------------------------------------------------
+
+if opt_tool(FORMATS, "NABUPC_DSK") then
+	files {
+		MAME_DIR.. "src/lib/formats/nabupc_dsk.cpp",
+		MAME_DIR.. "src/lib/formats/nabupc_dsk.h",
+	}
+end
+
 --------------------------------------------------
 --
 --@src/lib/formats/nanos_dsk.h,FORMATS["NANOS_DSK"] = true
@@ -2318,15 +2330,4 @@ if opt_tool(FORMATS, "FS_HP98X5") then
 	}
 end
 
---------------------------------------------------
---
---@src/lib/formats/nabupc_dsk.h,FORMATS["NABUPC_DSK"] = true
---------------------------------------------------
-
-if opt_tool(FORMATS, "NABUPC_DSK") then
-	files {
-		MAME_DIR.. "src/lib/formats/nabupc_dsk.cpp",
-		MAME_DIR.. "src/lib/formats/nabupc_dsk.h",
-	}
-end
 end

src/frontend/mame/luaengine_mem.cpp

@@ -11,6 +11,8 @@
 #include "emu.h"
 #include "luaengine.ipp"
 
+#include <cstring>
+
 
 namespace {
 
@@ -734,6 +736,21 @@ void lua_engine::initialize_memory(sol::table &emu)
 
 
 	auto region_type = sol().registry().new_usertype<memory_region>("region", sol::no_constructor);
+	region_type.set_function(
+			"read",
+			[] (memory_region &region, sol::this_state s, offs_t offset, offs_t length)
+			{
+				// TODO: should this do something special if the offset isn't a multiple of the byte width?
+				buffer_helper buf(s);
+				const offs_t limit = std::min<offs_t>(region.bytes(), offset + length);
+				const offs_t copyable = (limit > offset) ? (limit - offset) : 0;
+				auto space = buf.prepare(copyable);
+				if (copyable)
+					std::memcpy(space.get(), &region.as_u8(offset), copyable);
+				space.add(copyable);
+				buf.push();
+				return sol::make_reference(s, sol::stack_reference(s, -1));
+			});
 	region_type.set_function("read_i8", &region_read<s8>);
 	region_type.set_function("read_u8", &region_read<u8>);
 	region_type.set_function("read_i16", &region_read<s16>);

src/mame/layout/beena.lay

@@ -3,10 +3,68 @@
 license:CC0-1.0
 -->
 <mamelayout version="2">
-	<view name="Single Screen">
-		<bounds x="0" y="0" width="704" height="480" />
+	<element name="leftpage">
+		<!-- force maximum state -->
+		<rect state="0"><color alpha="0" /></rect>
+		<rect state="6"><color alpha="0" /></rect>
+	</element>
+	<element name="rightpage">
+		<!-- force maximum state -->
+		<rect state="0"><color alpha="0" /></rect>
+		<rect state="6"><color alpha="0" /></rect>
+	</element>
+
+	<view name="Default View">
 		<screen index="0">
-			<bounds left="0" top="0" right="704" bottom="480" />
+			<bounds x="0" y="0" width="4" height="3" />
 		</screen>
+
+		<element id="leftpage" ref="leftpage">
+			<bounds x="0" y="3.1" width="2" height="2.8" />
+		</element>
+		<element id="rightpage" ref="rightpage">
+			<bounds x="2" y="3.1" width="2" height="2.8" />
+		</element>
 	</view>
+
+	<script><![CDATA[
+		file:set_resolve_tags_callback(
+				function ()
+					-- get memory regions for page scans
+					local pages = { }
+					for i = 1, 12 do
+						local page = file.device:memregion(string.format('cartslot:page%u', i))
+						if page ~= nil then
+							pages[i] = page
+						else
+							break
+						end
+					end
+
+					-- make page display respond to page selection input
+					local pagectrl = file.device:ioport('PAGE')
+					local function get_page() return pagectrl:read() end
+					file.views['Default View'].items['leftpage']:set_element_state_callback(get_page)
+					file.views['Default View'].items['rightpage']:set_element_state_callback(get_page)
+
+					-- render even pages on the left, odd pages on the right
+					local function draw_page(n, dest)
+						local page = pages[n]
+						if page ~= nil then
+							-- TODO: reduce temporary memory usage when I/O classes are exposed to Lua
+							local data = page:read(0, page.size)
+							local image = emu.bitmap_argb32.load(data)
+							image:resample(dest)
+						end
+					end
+					file.elements['leftpage']:set_draw_callback(
+							function (state, bitmap)
+								draw_page(state * 2, bitmap)
+							end)
+					file.elements['rightpage']:set_draw_callback(
+							function (state, bitmap)
+								draw_page((state * 2) + 1, bitmap)
+							end)
+				end)
+	]]></script>
 </mamelayout>