Infinite_Map Perlin Noise -- Question

Questions
7

I actually initially followed your “draw_pixels” example, which took a while to study and understand. I’ve made some modifications to it, along with other algorithms like flood_fill(), etc. Here’s the bulk of it. Thanks for making those examples, by the way. Some of them have come in handy!

----------------------------------------------------------------
-- CONSTANTS
----------------------------------------------------------------

-- Size of canvas (pixels)
local WIDTH = 1024
local HEIGHT = 512

-- Buffer constructor info for convenience
local BUFFER_SIZE = WIDTH * HEIGHT
local BUFFER_INFO = { {
		name = hash("rgba"),
		type = buffer.VALUE_TYPE_UINT8,
		count = 4
} }

-- Texture header for convenience
local HEADER = {
	width = WIDTH,
	height = HEIGHT,
	type = resource.TEXTURE_TYPE_2D,
	format = resource.TEXTURE_FORMAT_RGBA,
	num_mip_maps = 1
}

----------------------------------------------------------------
-- HELPER FUNCTIONS
----------------------------------------------------------------

-- Paints a single pixel on the canvas
local function paint(self, x, y, r, g, b, a)
	assert(0 <= x and x < WIDTH and 0 <= y and y < HEIGHT)
	local index = y * WIDTH * 4 + x * 4 + 1
	self.stream[index + 0] = r
	self.stream[index + 1] = g
	self.stream[index + 2] = b
	self.stream[index + 3] = a
	self.dirty = true
end

-- Replicates a grid of pixels by copying it to the canvas
local function replicate(self, grid, grid_width, grid_height)
	assert(grid_width <= WIDTH and grid_height <= HEIGHT)
	for y = 0, grid_height - 1 do
		for x = 0, grid_width - 1 do
			local index = y * grid_width + x + 1
			paint(self, x, y, grid[index].x, grid[index].y, grid[index].z, grid[index].w)
		end
	end
end

----------------------------------------------------------------
-- ENGINE FUNCTIONS
----------------------------------------------------------------

-- Init canvas with a buffer and a stream with which to edit the buffer
function init(self)
	self.buffer = buffer.create(BUFFER_SIZE, BUFFER_INFO)
	self.stream = buffer.get_stream(self.buffer, hash("rgba"))
end

-- Update canvas with new pixels when dirty
function update(self, dt)
	if self.dirty then
		local path = go.get("#sprite", "texture0")
		resource.set_texture(path, HEADER, self.buffer)
		self.dirty = true
	end
end

-- Process paint request messages
function on_message(self, message_id, message, sender)
	if message_id == REPLICATE then
		replicate(self, message.grid, message.grid_width, message.grid_height)
	end
end
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