1 files changed, 216 insertions, 0 deletions
diff --git a/libs/hump/camera.lua b/libs/hump/camera.lua
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--- /dev/null
+++ b/libs/hump/camera.lua
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+--[[
+Copyright (c) 2010-2015 Matthias Richter
+
+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.
+]]--
+
+local _PATH = (...):match('^(.*[%./])[^%.%/]+$') or ''
+local cos, sin = math.cos, math.sin
+
+local camera = {}
+camera.__index = camera
+
+-- Movement interpolators (for camera locking/windowing)
+camera.smooth = {}
+
+function camera.smooth.none()
+	return function(dx,dy) return dx,dy end
+end
+
+function camera.smooth.linear(speed)
+	assert(type(speed) == "number", "Invalid parameter: speed = "..tostring(speed))
+	return function(dx,dy, s)
+		-- normalize direction
+		local d = math.sqrt(dx*dx+dy*dy)
+		local dts = math.min((s or speed) * love.timer.getDelta(), d) -- prevent overshooting the goal
+		if d > 0 then
+			dx,dy = dx/d, dy/d
+		end
+
+		return dx*dts, dy*dts
+	end
+end
+
+function camera.smooth.damped(stiffness)
+	assert(type(stiffness) == "number", "Invalid parameter: stiffness = "..tostring(stiffness))
+	return function(dx,dy, s)
+		local dts = love.timer.getDelta() * (s or stiffness)
+		return dx*dts, dy*dts
+	end
+end
+
+
+local function new(x,y, zoom, rot, smoother)
+	x,y  = x or love.graphics.getWidth()/2, y or love.graphics.getHeight()/2
+	zoom = zoom or 1
+	rot  = rot or 0
+	smoother = smoother or camera.smooth.none() -- for locking, see below
+	return setmetatable({x = x, y = y, scale = zoom, rot = rot, smoother = smoother}, camera)
+end
+
+function camera:lookAt(x,y)
+	self.x, self.y = x, y
+	return self
+end
+
+function camera:move(dx,dy)
+	self.x, self.y = self.x + dx, self.y + dy
+	return self
+end
+
+function camera:position()
+	return self.x, self.y
+end
+
+function camera:rotate(phi)
+	self.rot = self.rot + phi
+	return self
+end
+
+function camera:rotateTo(phi)
+	self.rot = phi
+	return self
+end
+
+function camera:zoom(mul)
+	self.scale = self.scale * mul
+	return self
+end
+
+function camera:zoomTo(zoom)
+	self.scale = zoom
+	return self
+end
+
+function camera:attach(x,y,w,h, noclip)
+	x,y = x or 0, y or 0
+	w,h = w or love.graphics.getWidth(), h or love.graphics.getHeight()
+
+	self._sx,self._sy,self._sw,self._sh = love.graphics.getScissor()
+	if not noclip then
+		love.graphics.setScissor(x,y,w,h)
+	end
+
+	local cx,cy = x+w/2, y+h/2
+	love.graphics.push()
+	love.graphics.translate(cx, cy)
+	love.graphics.scale(self.scale)
+	love.graphics.rotate(self.rot)
+	love.graphics.translate(-self.x, -self.y)
+end
+
+function camera:detach()
+	love.graphics.pop()
+	love.graphics.setScissor(self._sx,self._sy,self._sw,self._sh)
+end
+
+function camera:draw(...)
+	local x,y,w,h,noclip,func
+	local nargs = select("#", ...)
+	if nargs == 1 then
+		func = ...
+	elseif nargs == 5 then
+		x,y,w,h,func = ...
+	elseif nargs == 6 then
+		x,y,w,h,noclip,func = ...
+	else
+		error("Invalid arguments to camera:draw()")
+	end
+
+	self:attach(x,y,w,h,noclip)
+	func()
+	self:detach()
+end
+
+-- world coordinates to camera coordinates
+function camera:cameraCoords(x,y, ox,oy,w,h)
+	ox, oy = ox or 0, oy or 0
+	w,h = w or love.graphics.getWidth(), h or love.graphics.getHeight()
+
+	-- x,y = ((x,y) - (self.x, self.y)):rotated(self.rot) * self.scale + center
+	local c,s = cos(self.rot), sin(self.rot)
+	x,y = x - self.x, y - self.y
+	x,y = c*x - s*y, s*x + c*y
+	return x*self.scale + w/2 + ox, y*self.scale + h/2 + oy
+end
+
+-- camera coordinates to world coordinates
+function camera:worldCoords(x,y, ox,oy,w,h)
+	ox, oy = ox or 0, oy or 0
+	w,h = w or love.graphics.getWidth(), h or love.graphics.getHeight()
+
+	-- x,y = (((x,y) - center) / self.scale):rotated(-self.rot) + (self.x,self.y)
+	local c,s = cos(-self.rot), sin(-self.rot)
+	x,y = (x - w/2 - ox) / self.scale, (y - h/2 - oy) / self.scale
+	x,y = c*x - s*y, s*x + c*y
+	return x+self.x, y+self.y
+end
+
+function camera:mousePosition(ox,oy,w,h)
+	local mx,my = love.mouse.getPosition()
+	return self:worldCoords(mx,my, ox,oy,w,h)
+end
+
+-- camera scrolling utilities
+function camera:lockX(x, smoother, ...)
+	local dx, dy = (smoother or self.smoother)(x - self.x, self.y, ...)
+	self.x = self.x + dx
+	return self
+end
+
+function camera:lockY(y, smoother, ...)
+	local dx, dy = (smoother or self.smoother)(self.x, y - self.y, ...)
+	self.y = self.y + dy
+	return self
+end
+
+function camera:lockPosition(x,y, smoother, ...)
+	return self:move((smoother or self.smoother)(x - self.x, y - self.y, ...))
+end
+
+function camera:lockWindow(x, y, x_min, x_max, y_min, y_max, smoother, ...)
+	-- figure out displacement in camera coordinates
+	x,y = self:cameraCoords(x,y)
+	local dx, dy = 0,0
+	if x < x_min then
+		dx = x - x_min
+	elseif x > x_max then
+		dx = x - x_max
+	end
+	if y < y_min then
+		dy = y - y_min
+	elseif y > y_max then
+		dy = y - y_max
+	end
+
+	-- transform displacement to movement in world coordinates
+	local c,s = cos(-self.rot), sin(-self.rot)
+	dx,dy = (c*dx - s*dy) / self.scale, (s*dx + c*dy) / self.scale
+
+	-- move
+	self:move((smoother or self.smoother)(dx,dy,...))
+end
+
+-- the module
+return setmetatable({new = new, smooth = camera.smooth},
+	{__call = function(_, ...) return new(...) end})