Add fz_new_draw_device_with_bbox function

Restricts rendering to a sub rectangle of the supplied bbox.

2 files changed, 31 insertions, 0 deletions

diff --git a/draw/draw_device.c b/draw/draw_device.c
index 2ee0de77..3df440ef 100644
--- a/draw/draw_device.c
+++ b/draw/draw_device.c
@@ -1653,6 +1653,23 @@ fz_new_draw_device(fz_context *ctx, fz_pixmap *dest)
 }
 
 fz_device *
+fz_new_draw_device_with_bbox(fz_context *ctx, fz_pixmap *dest, fz_bbox clip)
+{
+	fz_device *dev = fz_new_draw_device(ctx, dest);
+	fz_draw_device *ddev = dev->user;
+
+	if (clip.x0 > ddev->stack[0].scissor.x0)
+		ddev->stack[0].scissor.x0 = clip.x0;
+	if (clip.x1 < ddev->stack[0].scissor.x1)
+		ddev->stack[0].scissor.x1 = clip.x1;
+	if (clip.y0 > ddev->stack[0].scissor.y0)
+		ddev->stack[0].scissor.y0 = clip.y0;
+	if (clip.y1 < ddev->stack[0].scissor.y1)
+		ddev->stack[0].scissor.y1 = clip.y1;
+	return dev;
+}
+
+fz_device *
 fz_new_draw_device_type3(fz_context *ctx, fz_pixmap *dest)
 {
 	fz_device *dev = fz_new_draw_device(ctx, dest);
diff --git a/fitz/fitz.h b/fitz/fitz.h
index 732cb9d2..1355c740 100644
--- a/fitz/fitz.h
+++ b/fitz/fitz.h
@@ -1518,6 +1518,20 @@ fz_device *fz_new_bbox_device(fz_context *ctx, fz_bbox *bboxp);
 fz_device *fz_new_draw_device(fz_context *ctx, fz_pixmap *dest);
 
 /*
+	fz_new_draw_device_with_bbox: Create a device to draw on a pixmap.
+
+	dest: Target pixmap for the draw device. See fz_new_pixmap*
+	for how to obtain a pixmap. The pixmap is not cleared by the
+	draw device, see fz_clear_pixmap* for how to clear it prior to
+	calling fz_new_draw_device. Free the device by calling
+	fz_free_device.
+
+	clip: Bounding box to restrict any marking operations of the
+	draw device.
+*/
+fz_device *fz_new_draw_device_with_bbox(fz_context *ctx, fz_pixmap *dest, fz_bbox clip);
+
+/*
 	Text extraction device: Used for searching, format conversion etc.
 
 	(In development - Subject to change in future versions)