camera.py

import math
import matrix

class Camera:
	def __init__(self, shader, width, height):
		self.width = width
		self.height = height

		self.mv_matrix = matrix.Matrix()
		self.p_matrix = matrix.Matrix()

		self.shader = shader
		self.shader_matrix_location = self.shader.find_uniform(b"matrix")

		self.input = [0, 0, 0]

		self.position = [0, 0, -3]
		self.rotation = [math.tau / 4, 0]
	
	def update_camera(self, delta_time):
		speed = 7
		multiplier = speed * delta_time

		self.position[1] += self.input[1] * multiplier

		if self.input[0] or self.input[2]:
			angle = self.rotation[0] + math.atan2(self.input[2], self.input[0]) - math.tau / 4

			self.position[0] += math.cos(angle) * multiplier
			self.position[2] += math.sin(angle) * multiplier
	
	def update_matrices(self):

		self.p_matrix.load_identity()
		self.p_matrix.perspective(90, float(self.width) / self.height, 0.1, 500)

		self.mv_matrix.load_identity()
		self.mv_matrix.rotate_2d(-(self.rotation[0] - math.tau / 4), self.rotation[1])
		self.mv_matrix.translate(-self.position[0], -self.position[1], self.position[2])

		mvp_matrix = self.p_matrix * self.mv_matrix
		self.shader.uniform_matrix(self.shader_matrix_location, mvp_matrix)