From b849e816eee20c256cf1da94f4ba9e233b13ac23 Mon Sep 17 00:00:00 2001 From: npm Date: Fri, 28 Oct 2016 12:47:48 -0700 Subject: Use CompositeMask instead of TransferBitmap when drawing type 3 text TransferBitmap seems to work improperly when the glyph boxes overlap. In particular, after drawing a glyph, the next glyph's blanks will override what the previous glyph drew, and this is not the correct behavior. While on it, use CheckedNumeric to do operations safely. For reference of somewhere where something similar is done, see: https://cs.chromium.org/chromium/src/third_party/pdfium/core/fxge/ge/cfx_renderdevice.cpp?sq=package:chromium&rcl=1477581616&l=988 BUG=513954 Review-Url: https://codereview.chromium.org/2461743002 --- core/fpdfapi/render/fpdf_render_text.cpp | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) (limited to 'core/fpdfapi') diff --git a/core/fpdfapi/render/fpdf_render_text.cpp b/core/fpdfapi/render/fpdf_render_text.cpp index b8f44f8bd9..7d29f5c87f 100644 --- a/core/fpdfapi/render/fpdf_render_text.cpp +++ b/core/fpdfapi/render/fpdf_render_text.cpp @@ -29,6 +29,7 @@ #include "core/fxge/cfx_graphstatedata.h" #include "core/fxge/cfx_pathdata.h" #include "core/fxge/cfx_renderdevice.h" +#include "third_party/base/numerics/safe_math.h" FX_BOOL CPDF_RenderStatus::ProcessText(CPDF_TextObject* textobj, const CFX_Matrix* pObj2Device, @@ -314,13 +315,25 @@ FX_BOOL CPDF_RenderStatus::ProcessType3Text(CPDF_TextObject* textobj, if (!glyph.m_pGlyph) continue; - bitmap.TransferBitmap( - static_cast( - (glyph.m_OriginX + glyph.m_pGlyph->m_Left - rect.left) * sa), - static_cast((glyph.m_OriginY - glyph.m_pGlyph->m_Top - rect.top) * - sd), - glyph.m_pGlyph->m_Bitmap.GetWidth(), - glyph.m_pGlyph->m_Bitmap.GetHeight(), &glyph.m_pGlyph->m_Bitmap, 0, 0); + pdfium::base::CheckedNumeric left = glyph.m_OriginX; + left += glyph.m_pGlyph->m_Left; + left -= rect.left; + left *= sa; + if (!left.IsValid()) + continue; + + pdfium::base::CheckedNumeric top = glyph.m_OriginY; + top -= glyph.m_pGlyph->m_Top; + top -= rect.top; + top *= sd; + if (!top.IsValid()) + continue; + + bitmap.CompositeMask(left.ValueOrDie(), top.ValueOrDie(), + glyph.m_pGlyph->m_Bitmap.GetWidth(), + glyph.m_pGlyph->m_Bitmap.GetHeight(), + &glyph.m_pGlyph->m_Bitmap, fill_argb, 0, 0, + FXDIB_BLEND_NORMAL, nullptr, FALSE, 0, nullptr); } m_pDevice->SetBitMask(&bitmap, rect.left, rect.top, fill_argb); return TRUE; -- cgit v1.2.3