-- LUA Script - precede every function and global member with lowercase name of script

ai_viewanimations_from = {}
ai_viewanimations_to = {}
ai_viewanimations_pressed = false
ai_viewanimations_loop = {}
ai_viewanimations_looping = {}
ai_viewanimations_first_frame = {}
ai_viewanimations_entity = nil
ai_viewanimations_frozen = false

function ai_viewanimations_angle_dist (x1, x2, z1, z2)
    x1 = x1 or 0
    x2 = x2 or 0
    z1 = z1 or 0
    z2 = z2 or 0

    local xdiff = x1 - x2
    local zdiff = z1 - z2
    local abs_xdiff = math.abs(xdiff)
	local abs_zdiff = math.abs(zdiff)
	
    if xdiff == 0 and zdiff == 0 then return 0, 0 end

    -- distance from object 1 to object 2
    local dist_to_obj = math.sqrt((abs_xdiff*abs_xdiff) + (abs_zdiff*abs_zdiff))

    local obj_angle = 0   -- angle from object to object, default north

    if abs_xdiff < 1 then
        if zdiff < 0 then
            -- straight south (ish)
            obj_angle = 180
        end
    elseif abs_zdiff < 1 then
        if xdiff < 0 then
            -- straight west (ish)  
            obj_angle = 270
        else
            -- straight east (ish)
            obj_angle = 90
        end
    else
        -- simple cases out of the way now for some math
        if xdiff > 0 then
            if zdiff > 0 then
                obj_angle = math.deg (math.asin (abs_xdiff / dist_to_obj))
            else
                obj_angle = 90 + math.deg (math.asin (abs_zdiff / dist_to_obj))
            end
        else
            if zdiff < 0 then
                obj_angle = 180 + math.deg (math.asin (abs_xdiff / dist_to_obj))
            else
                obj_angle = 270 + math.deg (math.asin (abs_zdiff / dist_to_obj))
            end
        end
    end

    return obj_angle, dist_to_obj
end

function ai_viewanimations_init(e)
    CharacterControlLimbo(e)
	ai_viewanimations_from[e] = 0
    ai_viewanimations_to[e] = 0
	ai_viewanimations_loop[e] = false
	ai_viewanimations_first_frame[e] = true
	SetAnimationSpeed(e, 0.5)
end

function ai_viewanimations_main(e)

    local angle, dist = ai_viewanimations_angle_dist(g_Entity[e]['x'], g_PlayerPosX,
	                                                 g_Entity[e]['z'], g_PlayerPosZ);
	
    if  dist < 1000 then
	    if ai_viewanimations_entity == nil then
		    ai_viewanimations_entity = e
		elseif ai_viewanimations_entity ~= e then
		    if  math.abs(g_PlayerAngY - angle) < 10 then
			    ai_viewanimations_entity = e
				ai_viewanimations_pressed = false
			end
		end
    end    
	
	if ai_viewanimations_entity == e then
		
        CharacterControlLimbo(e)
        if g_MouseClick==0 and g_KeyPressE==0 and g_Scancode==0 then
            ai_viewanimations_pressed = false
        end

        if g_KeyPressE==1 then
		    if g_KeyPressSHIFT==1 and not ai_viewanimations_pressed then
		        ai_viewanimations_pressed = true
			    if not ai_viewanimations_loop[e] then 
			        ai_viewanimations_loop[e] = true 
			    else
			        ai_viewanimations_loop[e] = false
					ai_viewanimations_looping[e] = false
			    end
		    
			elseif not ai_viewanimations_pressed then
			    ai_viewanimations_pressed = true
				if not ai_viewanimations_first_frame[e] then
				    ai_viewanimations_first_frame[e] = true
				else
				    ai_viewanimations_first_frame[e] = false
                end					
			end	
		end
		
        if g_KeyPressSHIFT==1 or not ai_viewanimations_pressed then
            if g_MouseClick==1 then
                StopAnimation(e)
				ai_viewanimations_looping[e] = false
				ai_viewanimations_pressed = true
				if ai_viewanimations_first_frame[e] then
                    ai_viewanimations_from[e] = ai_viewanimations_from[e] + 1
					if ai_viewanimations_from[e] > ai_viewanimations_to[e] then
					    ai_viewanimations_to[e] = ai_viewanimations_from[e]
					end
				else
				    ai_viewanimations_to[e] = ai_viewanimations_to[e] + 1
				end
            end
		
            if g_MouseClick==2 and ai_viewanimations_from[e] > 0 then
                StopAnimation(e)
				ai_viewanimations_looping[e] = false
				ai_viewanimations_pressed = true
                if ai_viewanimations_first_frame[e] then
                    ai_viewanimations_from[e] = ai_viewanimations_from[e] - 1
			    elseif ai_viewanimations_to[e] > ai_viewanimations_from[e] then
				    ai_viewanimations_to[e] = ai_viewanimations_to[e] -1
				end
            end
        end
		
		if not ai_viewanimations_loop[e] then
		    ai_viewanimations_looping[e] = false
		    if ai_viewanimations_first_frame[e] then
                SetAnimationFrame(e, ai_viewanimations_from[e])
                PromptLocal (e, "frame= " .. ai_viewanimations_from[e])
            else
			    SetAnimationFrame(e, ai_viewanimations_to[e])
			    PromptLocal (e, "to_frame= " .. ai_viewanimations_to[e])
			end
		else
		    if not ai_viewanimations_looping[e] then
			    SetAnimation(e)
		        SetAnimationFrames(ai_viewanimations_from[e], ai_viewanimations_to[e])
                LoopAnimation(e)
				ai_viewanimations_looping[e] = true
			end
		    PromptLocal (e, "from_frame= " .. ai_viewanimations_from[e] .. 
		                    " to_frame= " .. ai_viewanimations_to[e])
		end
		if g_Scancode==50 and not ai_viewanimations_pressed then
	        ai_viewanimations_pressed = true
			if not ai_viewanimations_frozen then
			    ai_viewanimations_frozen = true
			    FreezePlayer()
				HideHuds()
				SetPlayerWeapons(0)
			else
			    ai_viewanimations_frozen = false
			    UnFreezePlayer()
				ShowHuds()
				SetPlayerWeapons(1)
			end
		end
		Prompt("Mouse l/r inc/dec (+shift), E - toggle to/from (+shift to start looping)")
	end
	
end