pixeldrawer.py

from DrawingInterface import DrawingInterface

import pydiffvg
import torch
from torch.nn import functional as F
import skimage
import skimage.io
import random
import ttools.modules
import argparse
import math
import torchvision
import torchvision.transforms as transforms
import numpy as np
import PIL.Image

from util import str2bool

from perlin_numpy import generate_fractal_noise_3d

def rect_from_corners(p0, p1):
    x1, y1 = p0
    x2, y2 = p1
    pts = [[x1, y1], [x2, y1], [x2, y2], [x1, y2]]
    return pts

# canonical interpolation function, like https://p5js.org/reference/#/p5/map
def map_number(n, start1, stop1, start2, stop2):
  return ((n-start1)/(stop1-start1))*(stop2-start2)+start2;

def diamond_from_corners(p0, p1):
    x1, y1 = p0
    x2, y2 = p1
    n = 1
    hyA = map_number(-2, -n, n, y1, y2)
    hyB = map_number( 2, -n, n, y1, y2)
    hyH = map_number(     0, -n, n, y1, y2)
    hxH = map_number(     0, -n, n, x1, x2)
    pts = [[hxH, hyA], [x1, hyH], [hxH, hyB], [x2, hyH]]
    return pts

def tri_from_corners(p0, p1, is_up):
    x1, y1 = p0
    x2, y2 = p1
    n = 1
    hxA = map_number( 2, -n, n, x1, x2)
    hxB = map_number(-2, -n, n, x1, x2)
    hxH = map_number(     0, -n, n, x1, x2)
    if is_up:
        pts = [[hxH, y1], [hxB, y2], [hxA, y2]]
    else:
        pts = [[hxH, y2], [hxA, y1], [hxB, y1]]
    return pts

def hex_from_corners(p0, p1):
    x1, y1 = p0
    x2, y2 = p1
    n  = 3
    hyA = map_number(4, -n, n, y1, y2)
    hyB = map_number(2, -n, n, y1, y2)
    hyC = map_number(-2, -n, n, y1, y2)
    hyD = map_number(-4, -n, n, y1, y2)
    hxH = map_number(0, -n, n, x1, x2)
    pts = [[hxH, hyA], [x1, hyB], [x1, hyC], [hxH, hyD], [x2, hyC], [x2, hyB]]
    return pts

def knit_from_corners(p0, p1):
    x1, y1 = p0
    x2, y2 = p1
    xm = (x1 + x2) / 2.0
    lean_up = 0.45
    slump_down = 0.30
    fall_back = 0.2
    y_up1 = map_number(lean_up, 0, 1, y2, y1)
    y_up2 = map_number(1 + lean_up, 0, 1, y2, y1)
    y_down1 = map_number(slump_down, 0, 1, y1, y2)
    y_down2 = map_number(1 + slump_down, 0, 1, y1, y2)
    x_fall_back1 = map_number(fall_back, 0, 1, x2, xm)
    x_fall_back2 = map_number(fall_back, 0, 1, x1, xm)

    pts = []
    # center bottom
    pts.append([xm, y_down2])
    # vertical line on right side
    pts.extend([[x2, y_up1], [x2, y_up2]])
    # horizontal line back
    pts.append([x_fall_back1, y_up2])
    # center top
    pts.append([xm, y_down1])
    # back up to top
    pts.append([x_fall_back2, y_up2])
    # vertical line on left side
    pts.extend([[x1, y_up2], [x1, y_up1]])
    return pts

shift_pixel_types = ["hex", "rectshift", "diamond"]
   
def gkern(size, gamma):
    """
    creates gaussian kernel with side length `l` and a sigma of `sig`
    https://stackoverflow.com/a/43346070/6028830
    """
    sig = size/gamma
    ax = np.linspace(-(size - 1) / 2., (size - 1) / 2., size)
    gauss = np.exp(-0.5 * np.square(ax) / np.square(sig))
    kernel = -np.outer(gauss, gauss)
    kernel = (kernel-kernel.min()) / (kernel.max()-kernel.min())
    return kernel * (size**2) / np.sum(kernel) # normalize such that the sum of pixel was the same as the original

class PixelDrawer(DrawingInterface):
    @staticmethod
    def add_settings(parser):
        parser.add_argument("--pixel_size", nargs=2, type=int, help="Pixel size (width height)", default=None, dest='pixel_size')
        parser.add_argument("--pixel_scale", type=float, help="Pixel scale", default=None, dest='pixel_scale')
        parser.add_argument("--pixel_type", type=str, help="rect, rectshift, hex, tri, diamond, knit", default="rect", dest='pixel_type')
        parser.add_argument("--pixel_edge_check", type=str2bool, help="ensure grid is symmetric", default=True, dest='pixel_edge_check')
        parser.add_argument("--pixel_iso_check", type=str2bool, help="ensure tri and hex shapes are w/h scaled", default=True, dest='pixel_iso_check')
        return parser

    def __init__(self, settings):
        super(DrawingInterface, self).__init__()

        self.canvas_width = settings.size[0]
        self.canvas_height = settings.size[1]

        # current logic: assume 16x9, or 4x5, but check for 1x1 (all others must be provided explicitly)
        # TODO: could compute this based on output size instead?
        if settings.pixel_size is not None:
            self.num_cols, self.num_rows = settings.pixel_size
        elif self.canvas_width == self.canvas_height:
            self.num_cols, self.num_rows = [40, 40]
        elif self.canvas_width < self.canvas_height:
            self.num_cols, self.num_rows = [40, 50]
        else:
            self.num_cols, self.num_rows = [80, 45]

        self.pixel_type = settings.pixel_type

        if settings.pixel_iso_check and settings.pixel_size is None:
            if self.pixel_type == "tri":
                # auto-adjust triangles to be wider if not specified
                self.num_cols = int(1.414 * self.num_cols)
            elif self.pixel_type == "hex":
                # auto-adjust hexes to be narrower if not specified
                self.num_rows = int(1.414 * self.num_rows)
            elif self.pixel_type == "diamond":
                self.num_rows = int(2 * self.num_rows)
 
        # we can also "scale" pixels -- scaling "up" meaning fewer rows/cols, etc.
        if settings.pixel_scale is not None and settings.pixel_scale > 0:
            self.num_cols = int(self.num_cols / settings.pixel_scale)
            self.num_rows = int(self.num_rows / settings.pixel_scale)


        shrink = False
        if self.num_cols>self.canvas_width:
            shrink = True
            self.num_cols = self.canvas_width
        if self.num_rows>self.canvas_height:
            shrink = True
            self.num_rows = self.canvas_height
        if shrink:
            print('pixel grid size should not be larger than output pixel size: reducing pixel grid')

        print(f"Running pixeldrawer with {self.num_cols}x{self.num_rows} grid")

        if settings.pixel_edge_check:
            if self.pixel_type in shift_pixel_types:
                if self.num_cols % 2 == 0:
                    self.num_cols = self.num_cols + 1
                if self.num_rows % 2 == 0:
                    self.num_rows = self.num_rows + 1
            elif self.pixel_type == "tri":
                if self.num_cols % 2 == 0:
                    self.num_cols = self.num_cols + 1
                if self.num_rows % 2 == 1:
                    self.num_rows = self.num_rows + 1

        self.transparency = settings.transparency
        if self.transparency:
            if settings.alpha_use_g:
                self.gkern = torch.tensor(gkern(self.canvas_width, settings.alpha_gamma))
            else:
                self.gkern = None

    def load_model(self, settings, device):
        # gamma = 1.0

        # Use GPU if available
        pydiffvg.set_use_gpu(torch.cuda.is_available())
        pydiffvg.set_device(device)
        self.device = device

    def get_opts(self):
        return self.opts

    def rand_init(self, toksX, toksY):
        self.init_from_tensor(None)

    def encode_image(self, init_tensor):
        # print("----> SHAPE", self.num_rows, self.num_cols)
        canvas_width, canvas_height = self.canvas_width, self.canvas_height
        num_rows, num_cols = self.num_rows, self.num_cols
        cell_width = canvas_width / num_cols
        cell_height = canvas_height / num_rows

        tensor_cell_height = 0
        tensor_cell_width = 0
        max_tensor_num_subsamples = 4
        tensor_subsamples_x = []
        tensor_subsamples_y = []
        if init_tensor is not None:
            tensor_shape = init_tensor.shape
            tensor_cell_width = tensor_shape[3] / num_cols
            tensor_cell_height = tensor_shape[2] / num_rows
            if int(tensor_cell_width) < max_tensor_num_subsamples:
                tensor_subsamples_x = [i for i in range(int(tensor_cell_width))]
            else:
                step_size_x = tensor_cell_width / max_tensor_num_subsamples
                tensor_subsamples_x = [int(i*step_size_x) for i in range(max_tensor_num_subsamples)]
            if int(tensor_cell_height) < max_tensor_num_subsamples:
                tensor_subsamples_y = [i for i in range(int(tensor_cell_height))]
            else:
                step_size_y = tensor_cell_height / max_tensor_num_subsamples
                tensor_subsamples_y = [int(i*step_size_y) for i in range(max_tensor_num_subsamples)]

            # print(tensor_shape, tensor_cell_width, tensor_cell_height,tensor_subsamples_x,tensor_subsamples_y)

        # Initialize Random Pixels
        shapes = []
        shape_groups = []
        colors = []
        scaled_init_tensor = (init_tensor[0] + 1.0) / 2.0
        for r in range(num_rows):
            tensor_cur_y = int(r * tensor_cell_height)
            cur_y = r * cell_height
            num_cols_this_row = num_cols
            col_offset = 0
            if self.pixel_type in shift_pixel_types and r % 2 == 0:
                num_cols_this_row = num_cols - 1
                col_offset = 0.5
            for c in range(num_cols_this_row):
                tensor_cur_x =  (col_offset + c) * tensor_cell_width
                cur_x = (col_offset + c) * cell_width
                if init_tensor is None:
                    cell_color = torch.tensor([random.random(), random.random(), random.random(), 1.0])
                else:
                    try:
                        rgb_sum = [0, 0, 0]
                        rgb_count = 0
                        for t_x in tensor_subsamples_x:
                            cur_subsample_x = tensor_cur_x + t_x
                            for t_y in tensor_subsamples_y:
                                cur_subsample_y = tensor_cur_y + t_y
                                if(cur_subsample_x < tensor_shape[3] and cur_subsample_y < tensor_shape[2]):
                                    rgb_count += 1
                                    rgb_sum[0] += scaled_init_tensor[0][int(cur_subsample_y)][int(cur_subsample_x)]
                                    rgb_sum[1] += scaled_init_tensor[1][int(cur_subsample_y)][int(cur_subsample_x)]
                                    rgb_sum[2] += scaled_init_tensor[2][int(cur_subsample_y)][int(cur_subsample_x)]
                                else:
                                    print(f"Ignoring out of bounds entry: {cur_subsample_x},{cur_subsample_y}")
                        if rgb_count == 0:
                            print("init cell count is 0, this shouldn't happen. but it did?")
                            rgb_count = 1
                        cell_color = torch.tensor([rgb_sum[0]/rgb_count, rgb_sum[1]/rgb_count, rgb_sum[2]/rgb_count, 1.0])
                    except BaseException as error:
                        print("WTF", error)
                        mono_color = random.random()
                        cell_color = torch.tensor([mono_color, mono_color, mono_color, 1.0])
                        raise error
                colors.append(cell_color)
                p0 = [cur_x, cur_y]
                p1 = [cur_x+cell_width, cur_y+cell_height]

                if self.pixel_type == "hex":
                    pts = hex_from_corners(p0, p1)
                elif self.pixel_type == "tri":
                    pts = tri_from_corners(p0, p1, (r + c) % 2 == 0)
                elif self.pixel_type == "diamond":
                    pts = diamond_from_corners(p0, p1)
                elif self.pixel_type == "knit":
                    pts = knit_from_corners(p0, p1)
                else:
                    pts = rect_from_corners(p0, p1)
                pts = torch.tensor(pts, dtype=torch.float32).view(-1, 2)
                path = pydiffvg.Polygon(pts, True)

                # path = pydiffvg.Rect(p_min=torch.tensor(p0), p_max=torch.tensor(p1))
                shapes.append(path)
                path_group = pydiffvg.ShapeGroup(shape_ids = torch.tensor([len(shapes) - 1]), stroke_color = None, fill_color = cell_color)
                shape_groups.append(path_group)

        # Just some diffvg setup
        scene_args = pydiffvg.RenderFunction.serialize_scene(\
            canvas_width, canvas_height, shapes, shape_groups)
        render = pydiffvg.RenderFunction.apply
        img = render(canvas_width, canvas_height, 2, 2, 0, None, *scene_args)

        color_vars = []
        for group in shape_groups:
            group.fill_color.requires_grad = True
            color_vars.append(group.fill_color)

        return color_vars, img, shapes, shape_groups

    def init_from_tensor(self, init_tensor):
        self.color_vars, self.img, self.shapes, self.shape_groups = (
            self.encode_image(init_tensor)
        )

    def get_opts(self, decay_divisor=1):
        # Optimizers
        # points_optim = torch.optim.Adam(points_vars, lr=1.0)
        # width_optim = torch.optim.Adam(stroke_width_vars, lr=0.1)
        color_optim = torch.optim.Adam(self.color_vars, lr=0.03/decay_divisor)
        self.opts = [color_optim]
        return self.opts

    def reapply_from_tensor(self, new_tensor):
        color_vars, *_ = self.encode_image(new_tensor)
        for old_color_var, new_color_var in zip(self.color_vars, color_vars):
            old_color_var.data = new_color_var.data

    def get_z_from_tensor(self, ref_tensor):
        return None

    def get_num_resolutions(self):
        return None

    def synth(self, cur_iteration: int, return_transparency: bool=False):
        """Uses pydiffvg to render the image.

        Returns synthesized RGB image when return_transparency is False.
        Returns synthesized (RGB,A) tuple when return_transparency is True.
        """
        if cur_iteration < 0:
            return self.img

        render = pydiffvg.RenderFunction.apply
        scene_args = pydiffvg.RenderFunction.serialize_scene(\
            self.canvas_width, self.canvas_height, self.shapes, self.shape_groups)
        img = render(self.canvas_width, self.canvas_height, 2, 2, cur_iteration, None, *scene_args)
        img_h, img_w = img.shape[0], img.shape[1]
        alpha = img[:, :, 3:4]

        if return_transparency:
            res = [1,2,4,8,16][random.randint(0,4)] # resolution of the perlin noise
            noise = generate_fractal_noise_3d((img_h, img_w, 3), (res, res, 1))
            img = alpha * img[:, :, :3] + (1 - alpha) * torch.tensor(noise, dtype=torch.float32, device=self.device)
        else:
            img = alpha * img[:, :, :3]
        
        img = img[:, :, :3]
        img = img.unsqueeze(0)
        img = img.permute(0, 3, 1, 2) # NHWC -> NCHW
        # if cur_iteration == 0:
        #     print("SHAPE", img.shape)

        self.img = img

        if return_transparency:
            if self.gkern is not None:
                return img, alpha*self.gkern.to(self.device) # weight by the gaussian mask
            else:
                return img, alpha
        else:
            return img

    @torch.no_grad()
    def to_image(self):
        img = self.img.detach().cpu().numpy()[0]
        img = np.transpose(img, (1, 2, 0))
        img = np.clip(img, 0, 1)
        img = np.uint8(img * 255)
        pimg = PIL.Image.fromarray(img, mode="RGB")
        return pimg

    def clip_z(self):
        with torch.no_grad():
            for group in self.shape_groups:
                group.fill_color.data[:3].clamp_(0.0, 1.0)
                group.fill_color.data[3].clamp_(0.0 if self.transparency else 1.0, 1.0)

    def get_z(self):
        groups = []
        for g in self.shape_groups:
            groups.append(g.fill_color.data)
        groups =  torch.stack(groups)
        groups.requires_grad_()
        return groups

    def get_z_copy(self):
        shape_groups_copy = []
        for group in self.shape_groups:
            group_copy = torch.clone(group.fill_color.data)
            shape_groups_copy.append(group_copy)
        shape_groups_copy = torch.stack(shape_groups_copy)
        return shape_groups_copy

    def set_z(self, new_z):
        l = len(new_z)
        for l in range(len(new_z)):
            active_group = self.shape_groups[l]
            new_group = new_z[l]
            active_group.fill_color.data.copy_(new_group)
        return None

    @torch.no_grad()
    def to_svg(self):
        pydiffvg.save_svg("./pixels.svg", self.canvas_width, self.canvas_height, self.shapes, self.shape_groups)