PIKApp/app/display/pikadisplayshell-transform.c

1030 lines
33 KiB
C

/* PIKA - Photo and Image Kooker Application
* a rebranding of The GNU Image Manipulation Program (created with heckimp)
* A derived work which may be trivial. However, any changes may be (C)2023 by Aldercone Studio
*
* Original copyright, applying to most contents (license remains unchanged):
* Copyright (C) 1995 Spencer Kimball and Peter Mattis
*
* 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 <https://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <math.h>
#include <gegl.h>
#include <gtk/gtk.h>
#include "libpikamath/pikamath.h"
#include "display-types.h"
#include "core/pikaboundary.h"
#include "core/pikadrawable.h"
#include "core/pikaimage.h"
#include "core/pika-utils.h"
#include "pikadisplay.h"
#include "pikadisplayshell.h"
#include "pikadisplayshell-scroll.h"
#include "pikadisplayshell-transform.h"
/* local function prototypes */
static void pika_display_shell_transform_xy_f_noround (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gdouble *nx,
gdouble *ny);
/* public functions */
/**
* pika_display_shell_zoom_coords:
* @shell: a #PikaDisplayShell
* @image_coords: image coordinates
* @display_coords: returns the corresponding display coordinates
*
* Zooms from image coordinates to display coordinates, so that
* objects can be rendered at the correct points on the display.
**/
void
pika_display_shell_zoom_coords (PikaDisplayShell *shell,
const PikaCoords *image_coords,
PikaCoords *display_coords)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (image_coords != NULL);
g_return_if_fail (display_coords != NULL);
*display_coords = *image_coords;
display_coords->x = SCALEX (shell, image_coords->x);
display_coords->y = SCALEY (shell, image_coords->y);
display_coords->x -= shell->offset_x;
display_coords->y -= shell->offset_y;
}
/**
* pika_display_shell_unzoom_coords:
* @shell: a #PikaDisplayShell
* @display_coords: display coordinates
* @image_coords: returns the corresponding image coordinates
*
* Zooms from display coordinates to image coordinates, so that
* points on the display can be mapped to points in the image.
**/
void
pika_display_shell_unzoom_coords (PikaDisplayShell *shell,
const PikaCoords *display_coords,
PikaCoords *image_coords)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (display_coords != NULL);
g_return_if_fail (image_coords != NULL);
*image_coords = *display_coords;
image_coords->x += shell->offset_x;
image_coords->y += shell->offset_y;
image_coords->x /= shell->scale_x;
image_coords->y /= shell->scale_y;
}
/**
* pika_display_shell_zoom_xy:
* @shell:
* @x:
* @y:
* @nx:
* @ny:
*
* Zooms an image coordinate to a shell coordinate.
**/
void
pika_display_shell_zoom_xy (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gint *nx,
gint *ny)
{
gint64 tx;
gint64 ty;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
tx = x * shell->scale_x;
ty = y * shell->scale_y;
tx -= shell->offset_x;
ty -= shell->offset_y;
/* The projected coordinates might overflow a gint in the case of
* big images at high zoom levels, so we clamp them here to avoid
* problems.
*/
*nx = CLAMP (tx, G_MININT, G_MAXINT);
*ny = CLAMP (ty, G_MININT, G_MAXINT);
}
/**
* pika_display_shell_unzoom_xy:
* @shell: a #PikaDisplayShell
* @x: x coordinate in display coordinates
* @y: y coordinate in display coordinates
* @nx: returns x oordinate in image coordinates
* @ny: returns y coordinate in image coordinates
* @round: if %TRUE, round the results to the nearest integer;
* if %FALSE, simply cast them to @gint.
*
* Zoom from display coordinates to image coordinates, so that
* points on the display can be mapped to the corresponding points
* in the image.
**/
void
pika_display_shell_unzoom_xy (PikaDisplayShell *shell,
gint x,
gint y,
gint *nx,
gint *ny,
gboolean round)
{
gint64 tx;
gint64 ty;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
if (round)
{
tx = SIGNED_ROUND (((gdouble) x + shell->offset_x) / shell->scale_x);
ty = SIGNED_ROUND (((gdouble) y + shell->offset_y) / shell->scale_y);
}
else
{
tx = ((gint64) x + shell->offset_x) / shell->scale_x;
ty = ((gint64) y + shell->offset_y) / shell->scale_y;
}
*nx = CLAMP (tx, G_MININT, G_MAXINT);
*ny = CLAMP (ty, G_MININT, G_MAXINT);
}
/**
* pika_display_shell_zoom_xy_f:
* @shell: a #PikaDisplayShell
* @x: image x coordinate of point
* @y: image y coordinate of point
* @nx: returned shell canvas x coordinate
* @ny: returned shell canvas y coordinate
*
* Zooms from image coordinates to display shell canvas
* coordinates.
**/
void
pika_display_shell_zoom_xy_f (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gdouble *nx,
gdouble *ny)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
*nx = SCALEX (shell, x) - shell->offset_x;
*ny = SCALEY (shell, y) - shell->offset_y;
}
/**
* pika_display_shell_unzoom_xy_f:
* @shell: a #PikaDisplayShell
* @x: x coordinate in display coordinates
* @y: y coordinate in display coordinates
* @nx: place to return x coordinate in image coordinates
* @ny: place to return y coordinate in image coordinates
*
* This function is identical to pika_display_shell_unzoom_xy(),
* except that the input and output coordinates are doubles rather than
* ints, and consequently there is no option related to rounding.
**/
void
pika_display_shell_unzoom_xy_f (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gdouble *nx,
gdouble *ny)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
*nx = (x + shell->offset_x) / shell->scale_x;
*ny = (y + shell->offset_y) / shell->scale_y;
}
/**
* pika_display_shell_zoom_segments:
* @shell: a #PikaDisplayShell
* @src_segs: array of segments in image coordinates
* @dest_segs: returns the corresponding segments in display coordinates
* @n_segs: number of segments
*
* Zooms from image coordinates to display coordinates, so that
* objects can be rendered at the correct points on the display.
**/
void
pika_display_shell_zoom_segments (PikaDisplayShell *shell,
const PikaBoundSeg *src_segs,
PikaSegment *dest_segs,
gint n_segs,
gdouble offset_x,
gdouble offset_y)
{
gint i;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
for (i = 0; i < n_segs ; i++)
{
gdouble x1, x2;
gdouble y1, y2;
x1 = src_segs[i].x1 + offset_x;
x2 = src_segs[i].x2 + offset_x;
y1 = src_segs[i].y1 + offset_y;
y2 = src_segs[i].y2 + offset_y;
dest_segs[i].x1 = SCALEX (shell, x1) - shell->offset_x;
dest_segs[i].x2 = SCALEX (shell, x2) - shell->offset_x;
dest_segs[i].y1 = SCALEY (shell, y1) - shell->offset_y;
dest_segs[i].y2 = SCALEY (shell, y2) - shell->offset_y;
}
}
/**
* pika_display_shell_rotate_coords:
* @shell: a #PikaDisplayShell
* @image_coords: unrotated display coordinates
* @display_coords: returns the corresponding rotated display coordinates
*
* Rotates from unrotated display coordinates to rotated display
* coordinates, so that objects can be rendered at the correct points
* on the display.
**/
void
pika_display_shell_rotate_coords (PikaDisplayShell *shell,
const PikaCoords *unrotated_coords,
PikaCoords *rotated_coords)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (unrotated_coords != NULL);
g_return_if_fail (rotated_coords != NULL);
*rotated_coords = *unrotated_coords;
if (shell->rotate_transform)
cairo_matrix_transform_point (shell->rotate_transform,
&rotated_coords->x,
&rotated_coords->y);
}
/**
* pika_display_shell_unrotate_coords:
* @shell: a #PikaDisplayShell
* @display_coords: rotated display coordinates
* @image_coords: returns the corresponding unrotated display coordinates
*
* Rotates from rotated display coordinates to unrotated display coordinates.
**/
void
pika_display_shell_unrotate_coords (PikaDisplayShell *shell,
const PikaCoords *rotated_coords,
PikaCoords *unrotated_coords)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (rotated_coords != NULL);
g_return_if_fail (unrotated_coords != NULL);
*unrotated_coords = *rotated_coords;
if (shell->rotate_untransform)
cairo_matrix_transform_point (shell->rotate_untransform,
&unrotated_coords->x,
&unrotated_coords->y);
}
/**
* pika_display_shell_rotate_xy:
* @shell:
* @x:
* @y:
* @nx:
* @ny:
*
* Rotates an unrotated display coordinate to a rotated shell coordinate.
**/
void
pika_display_shell_rotate_xy (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gint *nx,
gint *ny)
{
gint64 tx;
gint64 ty;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
if (shell->rotate_transform)
cairo_matrix_transform_point (shell->rotate_transform, &x, &y);
tx = x;
ty = y;
/* The projected coordinates might overflow a gint in the case of
* big images at high zoom levels, so we clamp them here to avoid
* problems.
*/
*nx = CLAMP (tx, G_MININT, G_MAXINT);
*ny = CLAMP (ty, G_MININT, G_MAXINT);
}
/**
* pika_display_shell_unrotate_xy:
* @shell: a #PikaDisplayShell
* @x: x coordinate in rotated display coordinates
* @y: y coordinate in rotated display coordinates
* @nx: returns x oordinate in unrotated display coordinates
* @ny: returns y coordinate in unrotated display coordinates
*
* Rotate from rotated display coordinates to unrotated display
* coordinates.
**/
void
pika_display_shell_unrotate_xy (PikaDisplayShell *shell,
gint x,
gint y,
gint *nx,
gint *ny)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
if (shell->rotate_untransform)
{
gdouble fx = x;
gdouble fy = y;
cairo_matrix_transform_point (shell->rotate_untransform, &fx, &fy);
*nx = CLAMP (fx, G_MININT, G_MAXINT);
*ny = CLAMP (fy, G_MININT, G_MAXINT);
}
else
{
*nx = x;
*ny = y;
}
}
/**
* pika_display_shell_rotate_xy_f:
* @shell: a #PikaDisplayShell
* @x: image x coordinate of point
* @y: image y coordinate of point
* @nx: returned shell canvas x coordinate
* @ny: returned shell canvas y coordinate
*
* Rotates from untransformed display coordinates to rotated display
* coordinates.
**/
void
pika_display_shell_rotate_xy_f (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gdouble *nx,
gdouble *ny)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
*nx = x;
*ny = y;
if (shell->rotate_transform)
cairo_matrix_transform_point (shell->rotate_transform, nx, ny);
}
/**
* pika_display_shell_unrotate_xy_f:
* @shell: a #PikaDisplayShell
* @x: x coordinate in rotated display coordinates
* @y: y coordinate in rotated display coordinates
* @nx: place to return x coordinate in unrotated display coordinates
* @ny: place to return y coordinate in unrotated display coordinates
*
* This function is identical to pika_display_shell_unrotate_xy(),
* except that the input and output coordinates are doubles rather
* than ints.
**/
void
pika_display_shell_unrotate_xy_f (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gdouble *nx,
gdouble *ny)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
*nx = x;
*ny = y;
if (shell->rotate_untransform)
cairo_matrix_transform_point (shell->rotate_untransform, nx, ny);
}
void
pika_display_shell_rotate_bounds (PikaDisplayShell *shell,
gdouble x1,
gdouble y1,
gdouble x2,
gdouble y2,
gdouble *nx1,
gdouble *ny1,
gdouble *nx2,
gdouble *ny2)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
if (shell->rotate_transform)
{
gdouble tx1 = x1;
gdouble ty1 = y1;
gdouble tx2 = x1;
gdouble ty2 = y2;
gdouble tx3 = x2;
gdouble ty3 = y1;
gdouble tx4 = x2;
gdouble ty4 = y2;
cairo_matrix_transform_point (shell->rotate_transform, &tx1, &ty1);
cairo_matrix_transform_point (shell->rotate_transform, &tx2, &ty2);
cairo_matrix_transform_point (shell->rotate_transform, &tx3, &ty3);
cairo_matrix_transform_point (shell->rotate_transform, &tx4, &ty4);
*nx1 = MIN4 (tx1, tx2, tx3, tx4);
*ny1 = MIN4 (ty1, ty2, ty3, ty4);
*nx2 = MAX4 (tx1, tx2, tx3, tx4);
*ny2 = MAX4 (ty1, ty2, ty3, ty4);
}
else
{
*nx1 = x1;
*ny1 = y1;
*nx2 = x2;
*ny2 = y2;
}
}
void
pika_display_shell_unrotate_bounds (PikaDisplayShell *shell,
gdouble x1,
gdouble y1,
gdouble x2,
gdouble y2,
gdouble *nx1,
gdouble *ny1,
gdouble *nx2,
gdouble *ny2)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
if (shell->rotate_untransform)
{
gdouble tx1 = x1;
gdouble ty1 = y1;
gdouble tx2 = x1;
gdouble ty2 = y2;
gdouble tx3 = x2;
gdouble ty3 = y1;
gdouble tx4 = x2;
gdouble ty4 = y2;
cairo_matrix_transform_point (shell->rotate_untransform, &tx1, &ty1);
cairo_matrix_transform_point (shell->rotate_untransform, &tx2, &ty2);
cairo_matrix_transform_point (shell->rotate_untransform, &tx3, &ty3);
cairo_matrix_transform_point (shell->rotate_untransform, &tx4, &ty4);
*nx1 = MIN4 (tx1, tx2, tx3, tx4);
*ny1 = MIN4 (ty1, ty2, ty3, ty4);
*nx2 = MAX4 (tx1, tx2, tx3, tx4);
*ny2 = MAX4 (ty1, ty2, ty3, ty4);
}
else
{
*nx1 = x1;
*ny1 = y1;
*nx2 = x2;
*ny2 = y2;
}
}
/**
* pika_display_shell_transform_coords:
* @shell: a #PikaDisplayShell
* @image_coords: image coordinates
* @display_coords: returns the corresponding display coordinates
*
* Transforms from image coordinates to display coordinates, so that
* objects can be rendered at the correct points on the display.
**/
void
pika_display_shell_transform_coords (PikaDisplayShell *shell,
const PikaCoords *image_coords,
PikaCoords *display_coords)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (image_coords != NULL);
g_return_if_fail (display_coords != NULL);
*display_coords = *image_coords;
display_coords->x = SCALEX (shell, image_coords->x);
display_coords->y = SCALEY (shell, image_coords->y);
display_coords->x -= shell->offset_x;
display_coords->y -= shell->offset_y;
if (shell->rotate_transform)
cairo_matrix_transform_point (shell->rotate_transform,
&display_coords->x,
&display_coords->y);
}
/**
* pika_display_shell_untransform_coords:
* @shell: a #PikaDisplayShell
* @display_coords: display coordinates
* @image_coords: returns the corresponding image coordinates
*
* Transforms from display coordinates to image coordinates, so that
* points on the display can be mapped to points in the image.
**/
void
pika_display_shell_untransform_coords (PikaDisplayShell *shell,
const PikaCoords *display_coords,
PikaCoords *image_coords)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (display_coords != NULL);
g_return_if_fail (image_coords != NULL);
*image_coords = *display_coords;
if (shell->rotate_untransform)
cairo_matrix_transform_point (shell->rotate_untransform,
&image_coords->x,
&image_coords->y);
image_coords->x += shell->offset_x;
image_coords->y += shell->offset_y;
image_coords->x /= shell->scale_x;
image_coords->y /= shell->scale_y;
image_coords->xscale = shell->scale_x;
image_coords->yscale = shell->scale_y;
image_coords->angle = shell->rotate_angle / 360.0;
image_coords->reflect = shell->flip_horizontally ^ shell->flip_vertically;
if (shell->flip_vertically)
image_coords->angle += 0.5;
}
/**
* pika_display_shell_transform_xy:
* @shell:
* @x:
* @y:
* @nx:
* @ny:
*
* Transforms an image coordinate to a shell coordinate.
**/
void
pika_display_shell_transform_xy (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gint *nx,
gint *ny)
{
gint64 tx;
gint64 ty;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
tx = x * shell->scale_x;
ty = y * shell->scale_y;
tx -= shell->offset_x;
ty -= shell->offset_y;
if (shell->rotate_transform)
{
gdouble fx = tx;
gdouble fy = ty;
cairo_matrix_transform_point (shell->rotate_transform, &fx, &fy);
tx = fx;
ty = fy;
}
/* The projected coordinates might overflow a gint in the case of
* big images at high zoom levels, so we clamp them here to avoid
* problems.
*/
*nx = CLAMP (tx, G_MININT, G_MAXINT);
*ny = CLAMP (ty, G_MININT, G_MAXINT);
}
/**
* pika_display_shell_untransform_xy:
* @shell: a #PikaDisplayShell
* @x: x coordinate in display coordinates
* @y: y coordinate in display coordinates
* @nx: returns x oordinate in image coordinates
* @ny: returns y coordinate in image coordinates
* @round: if %TRUE, round the results to the nearest integer;
* if %FALSE, simply cast them to @gint.
*
* Transform from display coordinates to image coordinates, so that
* points on the display can be mapped to the corresponding points
* in the image.
**/
void
pika_display_shell_untransform_xy (PikaDisplayShell *shell,
gint x,
gint y,
gint *nx,
gint *ny,
gboolean round)
{
gint64 tx;
gint64 ty;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
if (shell->rotate_untransform)
{
gdouble fx = x;
gdouble fy = y;
cairo_matrix_transform_point (shell->rotate_untransform, &fx, &fy);
x = fx;
y = fy;
}
if (round)
{
tx = SIGNED_ROUND (((gdouble) x + shell->offset_x) / shell->scale_x);
ty = SIGNED_ROUND (((gdouble) y + shell->offset_y) / shell->scale_y);
}
else
{
tx = ((gint64) x + shell->offset_x) / shell->scale_x;
ty = ((gint64) y + shell->offset_y) / shell->scale_y;
}
*nx = CLAMP (tx, G_MININT, G_MAXINT);
*ny = CLAMP (ty, G_MININT, G_MAXINT);
}
/**
* pika_display_shell_transform_xy_f:
* @shell: a #PikaDisplayShell
* @x: image x coordinate of point
* @y: image y coordinate of point
* @nx: returned shell canvas x coordinate
* @ny: returned shell canvas y coordinate
*
* Transforms from image coordinates to display shell canvas
* coordinates.
**/
void
pika_display_shell_transform_xy_f (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gdouble *nx,
gdouble *ny)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
*nx = SCALEX (shell, x) - shell->offset_x;
*ny = SCALEY (shell, y) - shell->offset_y;
if (shell->rotate_transform)
cairo_matrix_transform_point (shell->rotate_transform, nx, ny);
}
/**
* pika_display_shell_untransform_xy_f:
* @shell: a #PikaDisplayShell
* @x: x coordinate in display coordinates
* @y: y coordinate in display coordinates
* @nx: place to return x coordinate in image coordinates
* @ny: place to return y coordinate in image coordinates
*
* This function is identical to pika_display_shell_untransform_xy(),
* except that the input and output coordinates are doubles rather than
* ints, and consequently there is no option related to rounding.
**/
void
pika_display_shell_untransform_xy_f (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gdouble *nx,
gdouble *ny)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
if (shell->rotate_untransform)
cairo_matrix_transform_point (shell->rotate_untransform, &x, &y);
*nx = (x + shell->offset_x) / shell->scale_x;
*ny = (y + shell->offset_y) / shell->scale_y;
}
void
pika_display_shell_transform_bounds (PikaDisplayShell *shell,
gdouble x1,
gdouble y1,
gdouble x2,
gdouble y2,
gdouble *nx1,
gdouble *ny1,
gdouble *nx2,
gdouble *ny2)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx1 != NULL);
g_return_if_fail (ny1 != NULL);
g_return_if_fail (nx2 != NULL);
g_return_if_fail (ny2 != NULL);
if (shell->rotate_transform)
{
gdouble tx1, ty1;
gdouble tx2, ty2;
gdouble tx3, ty3;
gdouble tx4, ty4;
pika_display_shell_transform_xy_f_noround (shell, x1, y1, &tx1, &ty1);
pika_display_shell_transform_xy_f_noround (shell, x1, y2, &tx2, &ty2);
pika_display_shell_transform_xy_f_noround (shell, x2, y1, &tx3, &ty3);
pika_display_shell_transform_xy_f_noround (shell, x2, y2, &tx4, &ty4);
*nx1 = MIN4 (tx1, tx2, tx3, tx4);
*ny1 = MIN4 (ty1, ty2, ty3, ty4);
*nx2 = MAX4 (tx1, tx2, tx3, tx4);
*ny2 = MAX4 (ty1, ty2, ty3, ty4);
}
else
{
pika_display_shell_transform_xy_f_noround (shell, x1, y1, nx1, ny1);
pika_display_shell_transform_xy_f_noround (shell, x2, y2, nx2, ny2);
}
}
void
pika_display_shell_untransform_bounds (PikaDisplayShell *shell,
gdouble x1,
gdouble y1,
gdouble x2,
gdouble y2,
gdouble *nx1,
gdouble *ny1,
gdouble *nx2,
gdouble *ny2)
{
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx1 != NULL);
g_return_if_fail (ny1 != NULL);
g_return_if_fail (nx2 != NULL);
g_return_if_fail (ny2 != NULL);
if (shell->rotate_untransform)
{
gdouble tx1, ty1;
gdouble tx2, ty2;
gdouble tx3, ty3;
gdouble tx4, ty4;
pika_display_shell_untransform_xy_f (shell, x1, y1, &tx1, &ty1);
pika_display_shell_untransform_xy_f (shell, x1, y2, &tx2, &ty2);
pika_display_shell_untransform_xy_f (shell, x2, y1, &tx3, &ty3);
pika_display_shell_untransform_xy_f (shell, x2, y2, &tx4, &ty4);
*nx1 = MIN4 (tx1, tx2, tx3, tx4);
*ny1 = MIN4 (ty1, ty2, ty3, ty4);
*nx2 = MAX4 (tx1, tx2, tx3, tx4);
*ny2 = MAX4 (ty1, ty2, ty3, ty4);
}
else
{
pika_display_shell_untransform_xy_f (shell, x1, y1, nx1, ny1);
pika_display_shell_untransform_xy_f (shell, x2, y2, nx2, ny2);
}
}
/* transforms a bounding box from image-space, uniformly scaled by a factor of
* 'scale', to display-space. this is equivalent to, but more accurate than,
* dividing the input by 'scale', and using
* pika_display_shell_transform_bounds(), in particular, in that if 'scale'
* equals 'shell->scale_x' or 'shell->scale_y', there is no loss in accuracy
* in the corresponding dimension due to scaling (although there might be loss
* of accuracy due to rotation or translation.)
*/
void
pika_display_shell_transform_bounds_with_scale (PikaDisplayShell *shell,
gdouble scale,
gdouble x1,
gdouble y1,
gdouble x2,
gdouble y2,
gdouble *nx1,
gdouble *ny1,
gdouble *nx2,
gdouble *ny2)
{
gdouble factor_x;
gdouble factor_y;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (scale > 0.0);
g_return_if_fail (nx1 != NULL);
g_return_if_fail (ny1 != NULL);
g_return_if_fail (nx2 != NULL);
g_return_if_fail (ny2 != NULL);
factor_x = shell->scale_x / scale;
factor_y = shell->scale_y / scale;
x1 = x1 * factor_x - shell->offset_x;
y1 = y1 * factor_y - shell->offset_y;
x2 = x2 * factor_x - shell->offset_x;
y2 = y2 * factor_y - shell->offset_y;
pika_display_shell_rotate_bounds (shell,
x1, y1, x2, y2,
nx1, ny1, nx2, ny2);
}
/* transforms a bounding box from display-space to image-space, uniformly
* scaled by a factor of 'scale'. this is equivalent to, but more accurate
* than, using pika_display_shell_untransform_bounds(), and multiplying the
* output by 'scale', in particular, in that if 'scale' equals 'shell->scale_x'
* or 'shell->scale_y', there is no loss in accuracy in the corresponding
* dimension due to scaling (although there might be loss of accuracy due to
* rotation or translation.)
*/
void
pika_display_shell_untransform_bounds_with_scale (PikaDisplayShell *shell,
gdouble scale,
gdouble x1,
gdouble y1,
gdouble x2,
gdouble y2,
gdouble *nx1,
gdouble *ny1,
gdouble *nx2,
gdouble *ny2)
{
gdouble factor_x;
gdouble factor_y;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
g_return_if_fail (scale > 0.0);
g_return_if_fail (nx1 != NULL);
g_return_if_fail (ny1 != NULL);
g_return_if_fail (nx2 != NULL);
g_return_if_fail (ny2 != NULL);
factor_x = scale / shell->scale_x;
factor_y = scale / shell->scale_y;
pika_display_shell_unrotate_bounds (shell,
x1, y1, x2, y2,
nx1, ny1, nx2, ny2);
*nx1 = (*nx1 + shell->offset_x) * factor_x;
*ny1 = (*ny1 + shell->offset_y) * factor_y;
*nx2 = (*nx2 + shell->offset_x) * factor_x;
*ny2 = (*ny2 + shell->offset_y) * factor_y;
}
/**
* pika_display_shell_untransform_viewport:
* @shell: a #PikaDisplayShell
* @clip: whether to clip the result to the image bounds
* @x: returns image x coordinate of display upper left corner
* @y: returns image y coordinate of display upper left corner
* @width: returns width of display measured in image coordinates
* @height: returns height of display measured in image coordinates
*
* This function calculates the part of the image, in image coordinates,
* that corresponds to the display viewport.
**/
void
pika_display_shell_untransform_viewport (PikaDisplayShell *shell,
gboolean clip,
gint *x,
gint *y,
gint *width,
gint *height)
{
gdouble x1, y1, x2, y2;
g_return_if_fail (PIKA_IS_DISPLAY_SHELL (shell));
pika_display_shell_untransform_bounds (shell,
0, 0,
shell->disp_width, shell->disp_height,
&x1, &y1,
&x2, &y2);
x1 = floor (x1);
y1 = floor (y1);
x2 = ceil (x2);
y2 = ceil (y2);
if (clip)
{
PikaImage *image = pika_display_get_image (shell->display);
x1 = MAX (x1, 0);
y1 = MAX (y1, 0);
x2 = MIN (x2, pika_image_get_width (image));
y2 = MIN (y2, pika_image_get_height (image));
}
if (x) *x = x1;
if (y) *y = y1;
if (width) *width = x2 - x1;
if (height) *height = y2 - y1;
}
/* private functions */
/* Same as pika_display_shell_transform_xy_f(), but doesn't do any rounding
* for the transformed coordinates.
*/
static void
pika_display_shell_transform_xy_f_noround (PikaDisplayShell *shell,
gdouble x,
gdouble y,
gdouble *nx,
gdouble *ny)
{
*nx = shell->scale_x * x - shell->offset_x;
*ny = shell->scale_y * y - shell->offset_y;
if (shell->rotate_transform)
cairo_matrix_transform_point (shell->rotate_transform, nx, ny);
}