zathura/adjustment.c

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6.1 KiB
C
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/* See LICENSE file for license and copyright information */
#include "adjustment.h"
#include "utils.h"
#include <math.h>
double
page_calc_height_width(zathura_document_t* document, double height,
double width, unsigned int* page_height,
unsigned int* page_width, bool rotate)
{
g_return_val_if_fail(document != NULL && page_height != NULL && page_width != NULL, 0.0);
double scale = zathura_document_get_scale(document);
if (rotate && zathura_document_get_rotation(document) % 180) {
*page_width = round(height * scale);
*page_height = round(width * scale);
scale = MAX(*page_width / height, *page_height / width);
} else {
*page_width = round(width * scale);
*page_height = round(height * scale);
scale = MAX(*page_width / width, *page_height / height);
}
return scale;
}
void
page_calc_position(zathura_document_t* document, double x, double y, double* xn,
double* yn)
{
g_return_if_fail(document != NULL && xn != NULL && yn != NULL);
const unsigned int rot = zathura_document_get_rotation(document);
if (rot == 90) {
*xn = 1 - y;
*yn = x;
} else if (rot == 180) {
*xn = 1 - x;
*yn = 1 - y;
} else if (rot == 270) {
*xn = y;
*yn = 1 - x;
} else {
*xn = x;
*yn = y;
}
}
unsigned int
position_to_page_number(zathura_document_t* document, double pos_x,
double pos_y)
{
g_return_val_if_fail(document != NULL, 0);
unsigned int doc_width, doc_height;
zathura_document_get_document_size(document, &doc_height, &doc_width);
unsigned int cell_width, cell_height;
zathura_document_get_cell_size(document, &cell_height, &cell_width);
unsigned int c0 = zathura_document_get_first_page_column(document);
unsigned int npag = zathura_document_get_number_of_pages(document);
unsigned int ncol = zathura_document_get_pages_per_row(document);
unsigned int nrow = (npag + c0 - 1 + ncol - 1) / ncol; /* number of rows */
unsigned int pad = zathura_document_get_page_padding(document);
unsigned int col = floor(pos_x * (double)doc_width / (double)(cell_width + pad));
unsigned int row = floor(pos_y * (double)doc_height / (double)(cell_height + pad));
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unsigned int page = ncol * (row % nrow) + (col % ncol);
if (page < c0 - 1) {
return 0;
} else {
return page - (c0 - 1);
}
}
void
page_number_to_position(zathura_document_t* document, unsigned int page_number,
double xalign, double yalign, double* pos_x,
double* pos_y)
{
g_return_if_fail(document != NULL);
unsigned int c0 = zathura_document_get_first_page_column(document);
unsigned int npag = zathura_document_get_number_of_pages(document);
unsigned int ncol = zathura_document_get_pages_per_row(document);
unsigned int nrow = (npag + c0 - 1 + ncol - 1) / ncol; /* number of rows */
/* row and column for page_number indexed from 0 */
unsigned int row = (page_number + c0 - 1) / ncol;
unsigned int col = (page_number + c0 - 1) % ncol;
/* sizes of page cell, viewport and document */
unsigned int cell_height = 0, cell_width = 0;
zathura_document_get_cell_size(document, &cell_height, &cell_width);
unsigned int view_height = 0, view_width = 0;
zathura_document_get_viewport_size(document, &view_height, &view_width);
unsigned int doc_height = 0, doc_width = 0;
zathura_document_get_document_size(document, &doc_height, &doc_width);
/* compute the shift to align to the viewport. If the page fits to viewport, just center it. */
double shift_x = 0.5, shift_y = 0.5;
if (cell_width > view_width) {
shift_x = 0.5 + (xalign - 0.5) * ((double)cell_width - (double)view_width) / (double)cell_width;
}
if (cell_height > view_height) {
shift_y = 0.5 + (yalign - 0.5) * ((double)cell_height - (double)view_height) / (double)cell_height;
}
/* compute the position */
*pos_x = ((double)col + shift_x) / (double)ncol;
*pos_y = ((double)row + shift_y) / (double)nrow;
}
bool
page_is_visible(zathura_document_t *document, unsigned int page_number)
{
g_return_val_if_fail(document != NULL, false);
/* position at the center of the viewport */
double pos_x = zathura_document_get_position_x(document);
double pos_y = zathura_document_get_position_y(document);
/* get the center of page page_number */
double page_x, page_y;
page_number_to_position(document, page_number, 0.5, 0.5, &page_x, &page_y);
unsigned int cell_width, cell_height;
zathura_document_get_cell_size(document, &cell_height, &cell_width);
unsigned int doc_width, doc_height;
zathura_document_get_document_size(document, &doc_height, &doc_width);
unsigned int view_width, view_height;
zathura_document_get_viewport_size(document, &view_height, &view_width);
return ( fabs(pos_x - page_x) < 0.5 * (double)(view_width + cell_width) / (double)doc_width &&
fabs(pos_y - page_y) < 0.5 * (double)(view_height + cell_height) / (double)doc_height);
}
void
zathura_adjustment_set_value(GtkAdjustment* adjustment, gdouble value)
{
gtk_adjustment_set_value(adjustment,
MAX(gtk_adjustment_get_lower(adjustment),
MIN(gtk_adjustment_get_upper(adjustment) -
gtk_adjustment_get_page_size(adjustment),
value)));
}
gdouble
zathura_adjustment_get_ratio(GtkAdjustment* adjustment)
{
gdouble lower = gtk_adjustment_get_lower(adjustment);
gdouble upper = gtk_adjustment_get_upper(adjustment);
gdouble page_size = gtk_adjustment_get_page_size(adjustment);
gdouble value = gtk_adjustment_get_value(adjustment);
return (value - lower + page_size / 2.0) / (upper - lower);
}
void
zathura_adjustment_set_value_from_ratio(GtkAdjustment* adjustment,
gdouble ratio)
{
if (ratio == 0.0) {
return;
}
gdouble lower = gtk_adjustment_get_lower(adjustment);
gdouble upper = gtk_adjustment_get_upper(adjustment);
gdouble page_size = gtk_adjustment_get_page_size(adjustment);
gdouble value = (upper - lower) * ratio + lower - page_size / 2.0;
zathura_adjustment_set_value(adjustment, value);
}