sh_firstperson.lua

-- Script for first person in Silent Hill in BizHawk
--
-- Submit improvments at https://gist.github.com/samfromcadott
--
-- Copyright 2021 Sam Jackson
-----------------------------

-- Memory addresses
-----------------------------

harryAddress = {
	x = 0x0BA024,
	y = 0x0BA028,
	z = 0x0BA02C,
	yaw = 0x0BA032
}

camAddress = {
	pitch = 0x0B9D88,
	yaw = 0x0B9D8A,
	roll = 0x0B9D8C,
	x = 0x0B9D20,
	y = 0x0B9D24,
	z = 0x0B9D28
}

-- Address 0x0B9D00 controls focal length

-- Functions
-----------------------------

function radian(angle)
	-- Converts from Silent Hill's angles (4096 per rotation) to radians
	return angle * math.pi/2048

end

function getHarry()
	return {
		x = memory.read_s32_le(harryAddress.x),
		y = memory.read_s32_le(harryAddress.y),
		z = memory.read_s32_le(harryAddress.z),
		yaw = memory.read_u16_le(harryAddress.yaw)
	}

end

-- Start up
-----------------------------

freeCam = false
headHeight = 6000
cameraOffset = 2900

-- Main loop
-----------------------------

while true do
	harry = getHarry()

	-- The camera should be moved forward into Harry's head
	facing = {
		x = math.sin(radian(harry.yaw)),
		y = 0.0,
		z = math.cos(radian(harry.yaw))
	}

	-- Transform the camera

	-- Location
	memory.write_s32_le(camAddress.x, harry.x+facing.x*cameraOffset)
	memory.write_s32_le(camAddress.y, harry.y-headHeight)
	memory.write_s32_le(camAddress.z, harry.z+facing.z*cameraOffset)

	-- Rotation
	memory.write_u16_le(camAddress.pitch, 0)
	memory.write_u16_le(camAddress.yaw, harry.yaw)
	memory.write_u16_le(camAddress.roll, 0)

	emu.frameadvance()

end