Second commit

Signed-off-by: Mattias Andrée <m@maandree.se>

1 files changed, 82 insertions, 0 deletions

diff --git a/zoom.c b/zoom.c
new file mode 100644
index 0000000..caa9884
--- /dev/null
+++ b/zoom.c
@@ -0,0 +1,82 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+#include <math.h> /* just for HUGE_VAL, no -lm needed */
+
+Zoom zoom = {1.0};
+enum zoom_mode zoom_mode = ZOOM_BEST_FIT;
+
+int
+zoom_eq(Zoom a, Zoom b)
+{
+	return FLOAT_EQ(a, b);
+}
+
+double
+get_zoom(Zoom z)
+{
+	return z;
+}
+
+Zoom
+make_zoom(double s)
+{
+	return s;
+}
+
+Zoom
+zoom_in(Zoom z)
+{
+	return get_zoom(z) * 1.25;
+}
+
+Zoom
+zoom_out(Zoom z)
+{
+	return get_zoom(z) * (1.0 / 1.25);
+}
+
+Zoom
+calculate_fit(GdkPixbuf *image, int xfit, int yfit, double cap)
+{
+	GtkAdjustment *adjustment;
+	double s = 1.0, y;
+	int w, h;
+
+	if (xfit) {
+		adjustment = logical_scroll_pane_get_hadjustment(LOGICAL_SCROLL_PANE(scroll));
+		w = gdk_pixbuf_get_width(image);
+		s = adjustment->page_size / (double)w;
+	}
+
+	if (yfit) {
+		adjustment = logical_scroll_pane_get_vadjustment(LOGICAL_SCROLL_PANE(scroll));
+		h = gdk_pixbuf_get_height(image);
+		y = adjustment->page_size / (double)h;
+		s = xfit ? MIN(s, y) : y;
+	}
+
+	if (s > cap)
+		s = cap;
+
+	return make_zoom(s);
+}
+
+Zoom
+calculate_zoom_mode(GdkPixbuf *image, enum zoom_mode mode)
+{
+	switch (mode) {
+	case ZOOM_CUSTOM:
+		break;
+	case ZOOM_NORMAL:
+		return calculate_fit(image, 0, 0, 1.0);
+	case ZOOM_FIT_WIDTH:
+		return calculate_fit(image, 1, 0, HUGE_VAL);
+	case ZOOM_FIT_HEIGHT:
+		return calculate_fit(image, 0, 1, HUGE_VAL);
+	case ZOOM_FIT_WINDOW:
+		return calculate_fit(image, 1, 1, HUGE_VAL);
+	case ZOOM_BEST_FIT:
+		return calculate_fit(image, 1, 1, 1.0);
+	}
+	return zoom;
+}