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--[[
Copyright (c) 2012 Xgoff
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
Except as contained in this notice, the name(s) of the above copyright holders
shall not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
--]]
assert(love._version:match "^0.8", "fakecanvas requires LOVE 0.8")
assert(debug, "fake canvases require access to the debug library")
local canvas_supported = love.graphics.isSupported "canvas"
local npot_supported = love.graphics.isSupported "npot"
local pixeleffect_supported = love.graphics.isSupported "pixeleffect"
local function nextpo2 (x) return 2^math.ceil(math.log(x) / math.log(2)) end
local function prevpo2 (x) return 2^math.floor(math.log(x) / math.log(2)) end
local _types = { "Canvas" == true, "Object" == true, "Drawable" == true }
local canvas = { }
local canvasmt = { __index = canvas }
local canvases = setmetatable({ }, { __mode = "k" })
local options = {
-- flip fake canvas images vertically (then unflip with quad) in order to
-- match real canvas orientation. this only makes a difference inside
-- shaders, when using the canvas' texture coordinates. if you do not need
-- to use this information, you can get a performance boost by disabling
-- this option. you can enable or disable vflipping for individual fake
-- canvases by placing setOption() calls around the newCanvas() call.
vflip = true,
}
local blank
function canvas:clear (...)
local nargs = select("#", ...)
if nargs == 0 then
local id = canvases[self]._imagedata
id:paste(blank, 0, 0, 0, 0, id:getWidth(), id:getHeight())
elseif nargs == 1 and type(...) == "table" then
local t = ...
local r, g, b, a = tonumber(t[1]) or 0, tonumber(t[2]) or 0, tonumber(t[3]) or 0, tonumber(t[4]) or 255
canvases[self]._imagedata:mapPixel(function () return r, g, b, a end)
else
local r, g, b, a = ...
r, g, b, a = tonumber(r) or 0, tonumber(g) or 0, tonumber(b) or 0, tonumber(a) or 255
canvases[self]._imagedata:mapPixel(function () return r, g, b, a end)
end
end
function canvas:getFilter ()
return canvases[self]._image:getFilter()
end
function canvas:getImageData ()
return canvases[self]._imagedata
end
function canvas:getWrap ()
return canvases[self]._image:getWrap()
end
function canvas:renderTo (renderfunc)
love.graphics.setCanvas(self)
renderfunc()
love.graphics.setCanvas()
end
function canvas:setFilter (min, mag)
canvases[self]._image:setFilter(min, mag)
end
function canvas:setWrap (h, v)
canvases[self]._image:setWrap(h, v)
end
function canvas:type ()
return "Canvas"
end
function canvas:typeOf (type)
return not not _types[type]
end
-- internal
function canvas:_getImage ()
return canvases[self]._image
end
function canvas:_getQuad ()
return canvases[self]._quad
end
local function Canvas (width, height)
local c = { }
local sw, sh = love.graphics.getWidth(), love.graphics.getHeight()
local w, h
if npot_supported then -- awesome, just limit to screen size
w = math.min(sw, tonumber(width) or sw)
h = math.min(sh, tonumber(height) or sh)
else -- well that sucks
w = math.min(prevpo2(sw), nextpo2(tonumber(width) or 1))
h = math.min(prevpo2(sh), nextpo2(tonumber(height) or 1))
end
c._imagedata = love.image.newImageData(w, h)
c._image = love.graphics.newImage(c._imagedata)
c._quad = love.graphics.newQuad(0, 0, w, h, w, h)
c._vflip = options.vflip
if options.vflip then
c._quad:flip(false, true) -- flip vertically part 0
end
local p = newproxy(true)
canvases[p] = c
getmetatable(p).__index = canvasmt.__index
return p
end
local current_canvas
local function getCanvas ()
return current_canvas
end
local _fb_states = { }
local ccount = 0
local function screenshot (state)
local canvas = state.canvas
love.graphics.setColor(255, 255, 255, 255)
local drawn = love.graphics.newScreenshot()
if canvas._vflip then -- flip vertically (unfortunately) so it can later be drawn unflipped in order to match texcoords of real canvases. part 1
love.graphics.setBackgroundColor(0, 0, 0, 0)
love.graphics.clear()
local flipped = love.graphics.newImage(drawn)
love.graphics.draw(flipped, 0, canvas._imagedata:getHeight(), 0, 1, -1)
drawn = love.graphics.newScreenshot()
end
canvas._imagedata:paste(drawn, 0, 0, 0, 0, canvas._imagedata:getWidth(), canvas._imagedata:getHeight())
canvas._image = love.graphics.newImage(canvas._imagedata) -- apparently images don't update when their imagedata changes, so
love.graphics.draw(canvas._image, 0, 0)
love.graphics.setBackgroundColor(unpack(state.color))
love.graphics.setScissor(unpack(state.scissor))
end
local function setCanvas (...)
assert(select("#", ...) == 0 or (select("#", ...) == 1 and type(...) == "userdata"), "Incorrect parameter type: expected userdata")
love.graphics.setStencil() -- fortunately LOVE does this as well which makes things much easier
local to = ...
if to then
local old_canvas = current_canvas
local current_canvas = canvases[to]
local current_state = {
canvas = current_canvas,
data = love.graphics.newScreenshot(),
color = { love.graphics.getBackgroundColor() },
scissor = { love.graphics.getScissor() },
}
current_state.image = love.graphics.newImage(current_state.data)
if #_fb_states > 0 then
screenshot(table.remove(_fb_states))
end
love.graphics.setScissor()
love.graphics.setBackgroundColor(0, 0, 0, 0)
love.graphics.clear()
table.insert(_fb_states, current_state)
else
if #_fb_states == 0 then return end -- only possible if multiple consecutive setCanvas() calls are made with no arguments; nothing to do
screenshot(table.remove(_fb_states))
while #_fb_states > 0 do
table.remove(_fb_states)
end
current_canvas = nil
end
end
local registry = debug.getregistry() -- naughty!
-- throwaway, forces LOVE to load the :send() method
if pixeleffect_supported then
love.graphics.newPixelEffect [[vec4 effect( vec4 x, Image y, vec2 z, vec2 w) { return vec4(0, 0, 0, 0); }]]
end
local _love_funcs = {
getCanvas = love.graphics.getCanvas,
setCanvas = love.graphics.setCanvas,
newCanvas = love.graphics.newCanvas,
draw = love.graphics.draw,
drawq = love.graphics.drawq,
pe_send = pixeleffect_supported and registry.PixelEffect.send,
--technically sendCanvas should also be wrapped but that's not officially exposed
}
local _wrap_funcs = {
getCanvas = getCanvas,
setCanvas = setCanvas,
newCanvas = Canvas,
draw = function (obj, x, y, r, sx, sy, ox, oy, kx, ky)
if canvases[obj] then
return _love_funcs.drawq(obj:_getImage(), obj:_getQuad(), x or 0, y or 0, r, sx, sy, ox, oy, kx, ky) -- flip texcoords part 2
end
return _love_funcs.draw(obj, x, y, r, sx, sy, ox, oy, kx, ky)
end,
drawq = function (obj, q, x, y, r, sx, sy, ox, oy, kx, ky)
if canvases[obj] then
return _love_funcs.drawq(obj:_getImage(), q or obj:_getQuad(), x, y, r, sx, sy, ox, oy, kx, ky)
end
return _love_funcs.drawq(obj, q, x, y, r, sx, sy, ox, oy, kx, ky)
end,
pe_send = function (pe, name, data)
if canvases[data] then
return _love_funcs.pe_send(pe, name, data:_getImage())
end
return _love_funcs.pe_send(pe, name, data)
end,
}
local M = { }
function M.enable (state)
if state == true or not canvas_supported then
love.graphics.getCanvas = _wrap_funcs.getCanvas
love.graphics.setCanvas = _wrap_funcs.setCanvas
love.graphics.newCanvas = _wrap_funcs.newCanvas
love.graphics.draw = _wrap_funcs.draw
love.graphics.drawq = _wrap_funcs.drawq
if pixeleffect_supported then
registry.PixelEffect.send = _wrap_funcs.pe_send
end
elseif state == false then
love.graphics.getCanvas = function () return nil end
love.graphics.setCanvas = function () end
love.graphics.newCanvas = function () error("canvases disabled", 2) end
love.graphics.draw = _love_funcs.draw
love.graphics.drawq = _love_funcs.drawq
if pixeleffect_supported then
registry.PixelEffect.send = _love_funcs.pe_send
end
elseif state == nil and canvas_supported then
love.graphics.getCanvas = _love_funcs.getCanvas
love.graphics.setCanvas = _love_funcs.setCanvas
love.graphics.newCanvas = _love_funcs.newCanvas
love.graphics.draw = _love_funcs.draw
love.graphics.drawq = _love_funcs.drawq
if pixeleffect_supported then
registry.PixelEffect.send = _love_funcs.pe_send
end
end
return M
end
function M.getMaxCanvasSize (hw, hh)
local w, h = love.graphics.getWidth(), love.graphics.getHeight()
hw, hh = tonumber(hw) or w, tonumber(hh) or h
if npot_supported then
return math.min(hw, w), math.min(hh, h)
else
return prevpo2(math.min(hw, w)), prevpo2(math.min(hh, h))
end
end
function M.setOption (name, value)
options[name] = value
end
function M.getOption (name)
return options[name]
end
blank = love.image.newImageData(M.getMaxCanvasSize())
M.enable()
return M
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