from casioplot import *
from img import *
import math

WIDTH = 100
HEIGHT = 100

TEX_WIDTH = TEXTURE_GRAPH90_WIDTH
TEX_HEIGHT = TEXTURE_GRAPH90_HEIGHT

zbuf = [32768 for i in range(WIDTH*HEIGHT)]

def edge(p1, p2, p3):
    return (p3[0] - p1[0]) * (p2[1] - p1[1]) - (p3[1] - p1[1]) * (p2[0] - p1[0])

def edge_start(x1, y1, x2, y2, px, py):
    return (y2 - y1) * (px - x1) - (x2 - x1) * (py - y1)

def triangle(p1, p2, p3, zbuf, color):
    x1, y1, z1, zn1, w1, h1 = p1
    x2, y2, z2, zn2, w2, h2 = p2
    x3, y3, z3, zn3, w3, h3 = p3

    if zn1 < 0 or zn2 < 0 or zn3 < 0:
        return

    min_x = max(0, min(x1, min(x2, x3)))
    max_x = min(WIDTH-1, max(x1, max(x2, x3)))
    min_y = max(0, min(y1, min(y2, y3)))
    max_y = min(HEIGHT-1, max(y1, max(y2, y3)))

    area = edge(p1, p2, p3)
    if area < 1:
        return

    w0 = w1 * z1
    h0 = h1 * z1
    w1 = w2 * z2
    h1 = h2 * z2
    w2 = w3 * z3
    h2 = h3 * z3

    u0_start = edge_start(x2, y2, x3, y3, min_x, min_y)
    u0_step_x = y3 - y2
    u0_step_y = x2 - x3
    u1_start = edge_start(x3, y3, x1, y1, min_x, min_y)
    u1_step_x = y1 - y3
    u1_step_y = x3 - x1
    u2_start = edge_start(x1, y1, x2, y2, min_x, min_y)
    u2_step_x = y2 - y1
    u2_step_y = x1 - x2

    z_num_start = int((u0_start * zn1 + u1_start * zn2 + u2_start * zn3) / area)
    z_num_step_x = int((u0_step_x * zn1 + u1_step_x * zn2 + u2_step_x * zn3) / area)
    z_num_step_y = int((u0_step_y * zn1 + u1_step_y * zn2 + u2_step_y * zn3) / area)

    z_div_start = u0_start * z1 + u1_start * z2 + u2_start * z3
    z_div_step_x = u0_step_x * z1 + u1_step_x * z2 + u2_step_x * z3
    z_div_step_y = u0_step_y * z1 + u1_step_y * z2 + u2_step_y * z3

    for x in range(min_x, max_x+1):
        u0 = u0_start
        u1 = u1_start
        u2 = u2_start
        z_num = z_num_start
        z_div = z_div_start

        for y in range(min_y, max_y+1):
            if (u0 | u1 | u2) > 0 and zbuf[y*WIDTH+x] > z_num:
                if color is None:
                    w = int(((u0 * w0 + u1 * w1 + u2 * w2) // z_div) % TEX_WIDTH)
                    h = int(((u0 * h0 + u1 * h1 + u2 * h2) // z_div) % TEX_HEIGHT)
                    row = TEXTURE_GRAPH90[h]
                    c = (row[3*w], row[3*w+1], row[3*w+2])
                else:
                    c = color

                # Put pixel
                r = c[0] * (32768-z_num) >> 15
                g = c[1] * (32768-z_num) >> 15
                b = c[2] * (32768-z_num) >> 15
                set_pixel(x, y, (r, g, b))
                zbuf[y*WIDTH+x] = z_num

            u0 += u0_step_y
            u1 += u1_step_y
            u2 += u2_step_y
            z_num += z_num_step_y
            z_div += z_div_step_y

        u0_start += u0_step_x
        u1_start += u1_step_x
        u2_start += u2_step_x
        z_num_start += z_num_step_x
        z_div_start += z_div_step_x

CAMERA_NEAR = 10
CAMERA_FAR = 60
SCREEN_CENTER_X = WIDTH // 2
SCREEN_CENTER_Y = HEIGHT // 2
SCREEN_SCALE = 15

def world2camera(vertices, camera):
    camera_vertices = []
    cx, cy, cz, ca1, ca2 = camera

    for x, y, z, w, h in vertices:
        x -= cx
        y -= cy
        z -= cz

        sin1 = math.sin(-ca1)
        cos1 = math.cos(-ca1)
        x, z = cos1*x - sin1*z, sin1*x + cos1*z

        sin2 = math.sin(-ca2)
        cos2 = math.cos(-ca2)
        y, z = cos2*y + sin2*z, -sin2*y + cos2*z

        camera_vertices.append((x, y, z, w, h))
    return camera_vertices

def camera2screen(vertices):
    screen = []
    for x, y, z, w, h in vertices:
        screen.append((
            int(+x * CAMERA_NEAR * SCREEN_SCALE / z + SCREEN_CENTER_X),
            int(-y * CAMERA_NEAR * SCREEN_SCALE / z + SCREEN_CENTER_Y),
            (1 << 15) / z,
            int((1 << 15) * (z - CAMERA_NEAR) / CAMERA_FAR),
            w*TEX_WIDTH,
            h*TEX_HEIGHT))
    return screen

vertices = [
    (-5,-9, 5, 0, 1), (-5,-9, 7, 0, 0), (-5,+9, 5, 0, 0), (-5,+9, 7, 0, 0),
    (+5,-9, 5, 1, 1), (+5,-9, 7, 0, 0), (+5,+9, 5, 1, 0), (+5,+9, 7, 0, 0),
]
faces = [
    # Bottom square
    (0, 1, 4),
    (4, 1, 5),
    # Top square
    (2, 6, 3),
    (3, 6, 7),
    # Front square
    (0, 4, 2),
    (2, 4, 6),
    # Left square
    (0, 2, 1),
    (1, 2, 3),
    # Right square
    (4, 5, 6),
    (6, 5, 7),
    # Back square
    (1, 3, 5),
    (5, 3, 7),
]
camera = [0, 17, -20, 0, -0.5] # x, y, z, ha, va

BLACK = (0x00, 0x00, 0x00)
GRAY1 = (0x40, 0x40, 0x40)
GRAY2 = (0x80, 0x80, 0x80)
GRAY3 = (0xc0, 0xc0, 0xc0)
GRAY4 = (0xe0, 0xe0, 0xe0)
colors = [GRAY4, GRAY4, GRAY3, GRAY3, None, None,
          GRAY2, GRAY2, GRAY2, GRAY2, GRAY1, GRAY1]

for i in range(33):
    angle = math.pi / 16 * i
    camera[0] = 30 * math.sin(angle)
    camera[2] = -30 * math.cos(angle) + 6
    camera[3] = angle

    for y in range(HEIGHT):
        for x in range(WIDTH):
            set_pixel(x, y, BLACK)

    for i in range(WIDTH*HEIGHT):
        zbuf[i] = 32768

    v_camera = world2camera(vertices, camera)
    v_screen = camera2screen(v_camera)

    for i in range(len(faces)):
        p1, p2, p3 = faces[i]
        triangle(v_screen[p1], v_screen[p2], v_screen[p3], zbuf, colors[i])

    show_screen()