pdf/pdf_transform.h

// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef PDF_PDF_TRANSFORM_H_
#define PDF_PDF_TRANSFORM_H_

#include "pdf/pdf_rect.h"
#include "ui/gfx/geometry/vector2d_f.h"

namespace gfx {
class Rect;
class SizeF;
}  // namespace gfx

namespace chrome_pdf {

// All the code here works in the PDF coordinate space. The origin is at the
// bottom-left, and all units are in points.

// Calculate the scale factor between `content_rect` and a page of `src_size`.
//
// `content_rect` specifies the printable area of the destination page.
// `src_size` specifies the source page size.
// `rotated` True if source page is rotated 90 degree or 270 degree.
float CalculateScaleFactor(const gfx::Rect& content_rect,
                           const gfx::SizeF& src_size,
                           bool rotated);

// Set the media box and/or crop box as needed. If both boxes are there, then
// nothing needs to be done. If one box is missing, then fill it with the value
// from the other box. If both boxes are missing, then they both get the default
// value from GetDefaultClipBox(), based on `rotated`.
void CalculateMediaBoxAndCropBox(bool rotated,
                                 bool has_media_box,
                                 bool has_crop_box,
                                 PdfRect* media_box,
                                 PdfRect* crop_box);

// Compute source clip box boundaries based on the crop box / media box of
// source page and scale factor.
// Returns the computed source clip box values.
//
// `media_box` The PDF's media box.
// `crop_box` The PDF's crop box.
PdfRect CalculateClipBoxBoundary(const PdfRect& media_box,
                                 const PdfRect& crop_box);

// Calculate the clip box translation offset for a page that does need to be
// scaled.
//
// `content_rect` specifies the printable area of the destination page.
// `source_clip_box` specifies the source clip box positions, relative to the
// origin.
// Returns the final translation offsets for the source clip box, relative to
// the origin.
gfx::Vector2dF CalculateScaledClipBoxOffset(const gfx::Rect& content_rect,
                                            const PdfRect& source_clip_box);

// Calculate the clip box offset for a page that does not need to be scaled.
//
// `rotation` specifies the source page rotation values which are N / 90
// degrees.
// `page_width` specifies the screen destination page width.
// `page_height` specifies the screen destination page height.
// `source_clip_box` specifies the source clip box positions, relative to the
// origin.
// Returns the final translation offsets for the source clip box, relative to
// the origin.
gfx::Vector2dF CalculateNonScaledClipBoxOffset(int rotation,
                                               int page_width,
                                               int page_height,
                                               const PdfRect& source_clip_box);

}  // namespace chrome_pdf

#endif  // PDF_PDF_TRANSFORM_H_