gimp/app/display/gimpdisplayshell-transform.c

316 lines
10 KiB
C

/* GIMP - The GNU Image Manipulation Program
* 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 <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include <gegl.h>
#include <gtk/gtk.h>
#include "libgimpmath/gimpmath.h"
#include "display-types.h"
#include "base/boundary.h"
#include "core/gimpdrawable.h"
#include "core/gimpimage.h"
#include "gimpdisplay.h"
#include "gimpdisplayshell.h"
#include "gimpdisplayshell-scroll.h"
#include "gimpdisplayshell-transform.h"
/**
* gimp_display_shell_transform_coords:
* @shell: a #GimpDisplayShell
* @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
gimp_display_shell_transform_coords (const GimpDisplayShell *shell,
const GimpCoords *image_coords,
GimpCoords *display_coords)
{
g_return_if_fail (GIMP_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;
}
/**
* gimp_display_shell_untransform_coords:
* @shell: a #GimpDisplayShell
* @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
gimp_display_shell_untransform_coords (const GimpDisplayShell *shell,
const GimpCoords *display_coords,
GimpCoords *image_coords)
{
g_return_if_fail (GIMP_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 = display_coords->x + shell->offset_x;
image_coords->y = display_coords->y + shell->offset_y;
image_coords->x /= shell->scale_x;
image_coords->y /= shell->scale_y;
}
/**
* gimp_display_shell_transform_xy:
* @shell:
* @x:
* @y:
* @nx:
* @ny:
*
* Transforms an image coordinate to a shell coordinate.
**/
void
gimp_display_shell_transform_xy (const GimpDisplayShell *shell,
gdouble x,
gdouble y,
gint *nx,
gint *ny)
{
gint64 tx;
gint64 ty;
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
tx = ((gint64) x * shell->x_src_dec) / shell->x_dest_inc;
ty = ((gint64) y * shell->y_src_dec) / shell->y_dest_inc;
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);
}
/**
* gimp_display_shell_untransform_xy:
* @shell: a #GimpDisplayShell
* @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
gimp_display_shell_untransform_xy (const GimpDisplayShell *shell,
gint x,
gint y,
gint *nx,
gint *ny,
gboolean round)
{
gint64 tx;
gint64 ty;
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
g_return_if_fail (nx != NULL);
g_return_if_fail (ny != NULL);
tx = (gint64) x + shell->offset_x;
ty = (gint64) y + shell->offset_y;
tx *= shell->x_dest_inc;
ty *= shell->y_dest_inc;
tx += round ? shell->x_dest_inc : shell->x_dest_inc >> 1;
ty += round ? shell->y_dest_inc : shell->y_dest_inc >> 1;
tx /= shell->x_src_dec;
ty /= shell->y_src_dec;
*nx = CLAMP (tx, G_MININT, G_MAXINT);
*ny = CLAMP (ty, G_MININT, G_MAXINT);
}
/**
* gimp_display_shell_transform_xy_f:
* @shell: a #GimpDisplayShell
* @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
gimp_display_shell_transform_xy_f (const GimpDisplayShell *shell,
gdouble x,
gdouble y,
gdouble *nx,
gdouble *ny)
{
g_return_if_fail (GIMP_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;
}
/**
* gimp_display_shell_untransform_xy_f:
* @shell: a #GimpDisplayShell
* @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 gimp_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
gimp_display_shell_untransform_xy_f (const GimpDisplayShell *shell,
gdouble x,
gdouble y,
gdouble *nx,
gdouble *ny)
{
g_return_if_fail (GIMP_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;
}
/**
* gimp_display_shell_transform_segments:
* @shell: a #GimpDisplayShell
* @src_segs: array of segments in image coordinates
* @dest_segs: returns the corresponding segments in display coordinates
* @n_segs: number of segments
*
* Transforms from image coordinates to display coordinates, so that
* objects can be rendered at the correct points on the display.
**/
void
gimp_display_shell_transform_segments (const GimpDisplayShell *shell,
const BoundSeg *src_segs,
GimpSegment *dest_segs,
gint n_segs,
gdouble offset_x,
gdouble offset_y)
{
gint i;
g_return_if_fail (GIMP_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;
}
}
/**
* gimp_display_shell_untransform_viewport:
* @shell: a #GimpDisplayShell
* @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, im image coordinates,
* that corresponds to the display viewport.
**/
void
gimp_display_shell_untransform_viewport (const GimpDisplayShell *shell,
gint *x,
gint *y,
gint *width,
gint *height)
{
GimpImage *image;
gint x1, y1, x2, y2;
g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
gimp_display_shell_untransform_xy (shell,
0, 0,
&x1, &y1,
FALSE);
gimp_display_shell_untransform_xy (shell,
shell->disp_width, shell->disp_height,
&x2, &y2,
FALSE);
image = gimp_display_get_image (shell->display);
if (x1 < 0)
x1 = 0;
if (y1 < 0)
y1 = 0;
if (x2 > gimp_image_get_width (image))
x2 = gimp_image_get_width (image);
if (y2 > gimp_image_get_height (image))
y2 = gimp_image_get_height (image);
if (x) *x = x1;
if (y) *y = y1;
if (width) *width = x2 - x1;
if (height) *height = y2 - y1;
}