#!/usr/bin/env python # Gimp-Python - allows the writing of Gimp plugins in Python. # Copyright (C) 1997 James Henstridge # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation; either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program. If not, see . # Algorithms stolen from the whirl and pinch plugin distributed with Gimp, # by Federico Mena Quintero and Scott Goehring # # This version does the same thing, except there is no preview, and it is # written in python and is slower. import math, struct from gimpfu import * class pixel_fetcher: def __init__(self, drawable): self.col = -1 self.row = -1 self.img_width = drawable.width self.img_height = drawable.height self.img_bpp = drawable.bpp self.img_has_alpha = drawable.has_alpha self.tile_width = gimp.tile_width() self.tile_height = gimp.tile_height() self.bg_colour = '\0\0\0\0' self.bounds = drawable.mask_bounds self.drawable = drawable self.tile = None def set_bg_colour(self, r, g, b, a): self.bg_colour = struct.pack('BBB', r,g,b) if self.img_has_alpha: self.bg_colour = self.bg_colour + chr(a) def get_pixel(self, x, y): sel_x1, sel_y1, sel_x2, sel_y2 = self.bounds if x < sel_x1 or x >= sel_x2 or y < sel_y1 or y >= sel_y2: return self.bg_colour col = x / self.tile_width coloff = x % self.tile_width row = y / self.tile_height rowoff = y % self.tile_height if col != self.col or row != self.row or self.tile == None: self.tile = self.drawable.get_tile(False, row, col) self.col = col self.row = row return self.tile[coloff, rowoff] class Dummy: pass def whirl_pinch(image, drawable, whirl, pinch, radius): self = Dummy() self.width = drawable.width self.height = drawable.height self.bpp = drawable.bpp self.has_alpha = drawable.has_alpha self.bounds = drawable.mask_bounds self.sel_x1, self.sel_y1, self.sel_x2, self.sel_y2 = \ drawable.mask_bounds self.sel_w = self.sel_x2 - self.sel_x1 self.sel_h = self.sel_y2 - self.sel_y1 self.cen_x = (self.sel_x1 + self.sel_x2 - 1) / 2.0 self.cen_y = (self.sel_y1 + self.sel_y2 - 1) / 2.0 xhsiz = (self.sel_w - 1) / 2.0 yhsiz = (self.sel_h - 1) / 2.0 if xhsiz < yhsiz: self.scale_x = yhsiz / xhsiz self.scale_y = 1.0 elif xhsiz > yhsiz: self.scale_x = 1.0 self.scale_y = xhsiz / yhsiz else: self.scale_x = 1.0 self.scale_y = 1.0 self.radius = max(xhsiz, yhsiz); if not drawable.is_rgb and not drawable.is_grey: return gimp.tile_cache_ntiles(2 * (1 + self.width / gimp.tile_width())) whirl = whirl * math.pi / 180 dest_rgn = drawable.get_pixel_rgn(self.sel_x1, self.sel_y1, self.sel_w, self.sel_h, True, True) pft = pixel_fetcher(drawable) pfb = pixel_fetcher(drawable) bg_colour = gimp.get_background() pft.set_bg_colour(bg_colour[0], bg_colour[1], bg_colour[2], 0) pfb.set_bg_colour(bg_colour[0], bg_colour[1], bg_colour[2], 0) progress = 0 max_progress = self.sel_w * self.sel_h gimp.progress_init("Whirling and pinching") self.radius2 = self.radius * self.radius * radius pixel = ['', '', '', ''] values = [0,0,0,0] for row in range(self.sel_y1, (self.sel_y1+self.sel_y2)/2+1): top_p = '' bot_p = '' for col in range(self.sel_x1, self.sel_x2): q, cx, cy = calc_undistorted_coords(self, col, row, whirl, pinch, radius) if q: if cx >= 0: ix = int(cx) else: ix = -(int(-cx) + 1) if cy >= 0: iy = int(cy) else: iy = -(int(-cx) + 1) pixel[0] = pft.get_pixel(ix, iy) pixel[1] = pft.get_pixel(ix+1, iy) pixel[2] = pft.get_pixel(ix, iy+1) pixel[3] = pft.get_pixel(ix+1, iy+1) for i in range(self.bpp): values[0] = ord(pixel[0][i]) values[1] = ord(pixel[1][i]) values[2] = ord(pixel[2][i]) values[3] = ord(pixel[3][i]) top_p = top_p + bilinear(cx,cy, values) cx = self.cen_x + (self.cen_x - cx) cy = self.cen_y + (self.cen_y - cy) if cx >= 0: ix = int(cx) else: ix = -(int(-cx) + 1) if cy >= 0: iy = int(cy) else: iy = -(int(-cy) + 1) pixel[0] = pfb.get_pixel(ix, iy) pixel[1] = pfb.get_pixel(ix+1, iy) pixel[2] = pfb.get_pixel(ix, iy+1) pixel[3] = pfb.get_pixel(ix+1, iy+1) tmp = '' for i in range(self.bpp): values[0] = ord(pixel[0][i]) values[1] = ord(pixel[1][i]) values[2] = ord(pixel[2][i]) values[3] = ord(pixel[3][i]) tmp = tmp + bilinear(cx,cy, values) bot_p = tmp + bot_p else: top_p = top_p + pft.get_pixel(col, row) bot_p = pfb.get_pixel((self.sel_x2 - 1) - (col - self.sel_x1), (self.sel_y2-1) - (row - self.sel_y1)) + bot_p dest_rgn[self.sel_x1:self.sel_x2, row] = top_p dest_rgn[self.sel_x1:self.sel_x2, (self.sel_y2 - 1) - (row - self.sel_y1)] = bot_p progress = progress + self.sel_w * 2 gimp.progress_update(float(progress) / max_progress) drawable.flush() drawable.merge_shadow(True) drawable.update(self.sel_x1,self.sel_y1,self.sel_w,self.sel_h) def calc_undistorted_coords(self, wx, wy, whirl, pinch, radius): dx = (wx - self.cen_x) * self.scale_x dy = (wy - self.cen_y) * self.scale_y d = dx * dx + dy * dy inside = d < self.radius2 if inside: dist = math.sqrt(d / radius) / self.radius if (d == 0.0): factor = 1.0 else: factor = math.pow(math.sin(math.pi / 2 * dist), -pinch) dx = dx * factor dy = dy * factor factor = 1 - dist ang = whirl * factor * factor sina = math.sin(ang) cosa = math.cos(ang) x = (cosa * dx - sina * dy) / self.scale_x + self.cen_x y = (sina * dx + cosa * dy) / self.scale_y + self.cen_y else: x = wx y = wy return inside, float(x), float(y) def bilinear(x, y, values): x = x % 1.0 y = y % 1.0 m0 = values[0] + x * (values[1] - values[0]) m1 = values[2] + x * (values[3] - values[2]) return chr(int(m0 + y * (m1 - m0))) register( "python-fu-whirl-pinch", "Distorts an image by whirling and pinching", "Distorts an image by whirling and pinching", "James Henstridge (translated from C plugin)", "James Henstridge", "1997-1999", "_Whirl and Pinch (Py)...", "RGB*, GRAY*", [ (PF_IMAGE, "image", "Input image", None), (PF_DRAWABLE, "drawable", "Input drawable", None), (PF_SLIDER, "whirl", "Whirl angle", 90, (-360, 360, 1)), (PF_FLOAT, "pinch", "Pinch amount", 0), (PF_FLOAT, "radius", "radius", 1) ], [], whirl_pinch, menu="/Filters/Distorts") main()