1 // Copyright 2016 PDFium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
6 
7 #include "core/fpdfapi/render/cpdf_scaledrenderbuffer.h"
8 
9 #include "core/fpdfapi/render/cpdf_rendercontext.h"
10 #include "core/fpdfapi/render/cpdf_renderoptions.h"
11 #include "core/fxge/cfx_defaultrenderdevice.h"
12 #include "core/fxge/dib/cfx_dibitmap.h"
13 #include "third_party/base/ptr_util.h"
14 
15 #define _FPDFAPI_IMAGESIZE_LIMIT_ (30 * 1024 * 1024)
16 
CPDF_ScaledRenderBuffer()17 CPDF_ScaledRenderBuffer::CPDF_ScaledRenderBuffer() {}
18 
~CPDF_ScaledRenderBuffer()19 CPDF_ScaledRenderBuffer::~CPDF_ScaledRenderBuffer() {}
20 
Initialize(CPDF_RenderContext * pContext,CFX_RenderDevice * pDevice,const FX_RECT & pRect,const CPDF_PageObject * pObj,const CPDF_RenderOptions * pOptions,int max_dpi)21 bool CPDF_ScaledRenderBuffer::Initialize(CPDF_RenderContext* pContext,
22                                          CFX_RenderDevice* pDevice,
23                                          const FX_RECT& pRect,
24                                          const CPDF_PageObject* pObj,
25                                          const CPDF_RenderOptions* pOptions,
26                                          int max_dpi) {
27   m_pDevice = pDevice;
28   if (m_pDevice->GetDeviceCaps(FXDC_RENDER_CAPS) & FXRC_GET_BITS)
29     return true;
30 
31   m_pContext = pContext;
32   m_Rect = pRect;
33   m_pObject = pObj;
34   m_Matrix.Translate(-pRect.left, -pRect.top);
35   int horz_size = pDevice->GetDeviceCaps(FXDC_HORZ_SIZE);
36   int vert_size = pDevice->GetDeviceCaps(FXDC_VERT_SIZE);
37   if (horz_size && vert_size && max_dpi) {
38     int dpih =
39         pDevice->GetDeviceCaps(FXDC_PIXEL_WIDTH) * 254 / (horz_size * 10);
40     int dpiv =
41         pDevice->GetDeviceCaps(FXDC_PIXEL_HEIGHT) * 254 / (vert_size * 10);
42     if (dpih > max_dpi)
43       m_Matrix.Scale((float)(max_dpi) / dpih, 1.0f);
44     if (dpiv > max_dpi)
45       m_Matrix.Scale(1.0f, (float)(max_dpi) / (float)dpiv);
46   }
47   m_pBitmapDevice = pdfium::MakeUnique<CFX_DefaultRenderDevice>();
48   FXDIB_Format dibFormat = FXDIB_Rgb;
49   int32_t bpp = 24;
50   if (m_pDevice->GetDeviceCaps(FXDC_RENDER_CAPS) & FXRC_ALPHA_OUTPUT) {
51     dibFormat = FXDIB_Argb;
52     bpp = 32;
53   }
54   while (1) {
55     FX_RECT bitmap_rect =
56         m_Matrix.TransformRect(CFX_FloatRect(pRect)).GetOuterRect();
57     int32_t iWidth = bitmap_rect.Width();
58     int32_t iHeight = bitmap_rect.Height();
59     int32_t iPitch = (iWidth * bpp + 31) / 32 * 4;
60     if (iWidth * iHeight < 1)
61       return false;
62 
63     if (iPitch * iHeight <= _FPDFAPI_IMAGESIZE_LIMIT_ &&
64         m_pBitmapDevice->Create(iWidth, iHeight, dibFormat, nullptr)) {
65       break;
66     }
67     m_Matrix.Scale(0.5f, 0.5f);
68   }
69   m_pContext->GetBackground(m_pBitmapDevice->GetBitmap(), m_pObject.Get(),
70                             pOptions, &m_Matrix);
71   return true;
72 }
73 
OutputToDevice()74 void CPDF_ScaledRenderBuffer::OutputToDevice() {
75   if (m_pBitmapDevice) {
76     m_pDevice->StretchDIBits(m_pBitmapDevice->GetBitmap(), m_Rect.left,
77                              m_Rect.top, m_Rect.Width(), m_Rect.Height());
78   }
79 }
80