Add "sendregion" command to GPU

This allows part of a buffer to be sent instead of the whole thing, meaning that driving digiscreen arrays can now be done with fewer commands and no temporary buffers.
This also greatly improves the speed of doing so, and I suppose also allows hardware-accelerated scrolling if your display is smaller than 64x64...

1 files changed, 27 insertions, 0 deletions

diff --git a/gpu.lua b/gpu.lua
index 87ff6ea..9529002 100644
--- a/gpu.lua
+++ b/gpu.lua
@@ -201,6 +201,33 @@ local function runcommand(pos,meta,command)
 		if type(buffer) == "table" then
 			digiline:receptor_send(pos,digiline.rules.default,command.channel,buffer)
 		end
+	elseif command.command == "sendregion" then
+		if type(command.buffer) ~= "number" or type(command.channel) ~= "string" then return end
+		local bufnum = math.floor(command.buffer)
+		if bufnum < 0 or bufnum > 7 then return end
+		local buffer = meta:get_string("buffer"..bufnum)
+		if string.len(buffer) == 0 then return end
+		buffer = minetest.deserialize(buffer)
+		if type(buffer) ~= "table" then return end
+		if type(command.x1) ~= "number" or type(command.x2) ~= "number" or type(command.y1) ~= "number" or type(command.x2) ~= "number" then return end
+		local x1 = math.min(64,math.floor(command.x1))
+		local y1 = math.min(64,math.floor(command.y1))
+		local x2 = math.min(64,math.floor(command.x2))
+		local y2 = math.min(64,math.floor(command.y2))	
+		if x1 < 1 or y1 < 1 or x2 < 1 or y2 < 1 then return end
+		x2 = math.min(x2,buffer.xsize)
+		y2 = math.min(y2,buffer.ysize)
+		if x1 > x2 or y1 > y2 then return end
+		local tempbuf = {}
+		for y=y1,y2,1 do
+			local dsty = y-y1+1
+			tempbuf[dsty] = {}
+			for x=x1,x2,1 do
+				local dstx = x-x1+1
+				tempbuf[dsty][dstx] = buffer[y][x]
+			end
+		end
+		digiline:receptor_send(pos,digiline.rules.default,command.channel,tempbuf)
 	elseif command.command == "drawrect" then
 		if type(command.buffer) ~= "number" or type(command.x1) ~= "number" or type(command.y1) ~= "number" or type(command.x2) ~= "number" or type(command.y2) ~= "number" then return end
 		local bufnum = math.floor(command.buffer)