The Tor Browser / annotate

gfx/layers/composite/TextRenderer.cpp@97036ab72558 (annotated)

gfx/layers/composite/TextRenderer.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author
Michael Schloh von Bennewitz <michael@schloh.com>
date
Tue, 06 Jan 2015 21:39:09 +0100
branch
TOR_BUG_9701
changeset 8
97036ab72558
permissions
-rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

michael@0 1 /* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
michael@0 2 /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0 3 * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0 4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0 5
michael@0 6 #include "TextRenderer.h"
michael@0 7 #include "FontData.h"
michael@0 8 #include "png.h"
michael@0 9 #include "mozilla/Base64.h"
michael@0 10 #include "mozilla/layers/Compositor.h"
michael@0 11 #include "mozilla/layers/TextureHost.h"
michael@0 12 #include "mozilla/layers/Effects.h"
michael@0 13
michael@0 14 namespace mozilla {
michael@0 15 namespace layers {
michael@0 16
michael@0 17 using namespace gfx;
michael@0 18 using namespace std;
michael@0 19
michael@0 20 const Float sBackgroundOpacity = 0.6f;
michael@0 21 const SurfaceFormat sTextureFormat = SurfaceFormat::B8G8R8A8;
michael@0 22
michael@0 23 static void PNGAPI info_callback(png_structp png_ptr, png_infop info_ptr)
michael@0 24 {
michael@0 25 png_read_update_info(png_ptr, info_ptr);
michael@0 26 }
michael@0 27
michael@0 28 static void PNGAPI row_callback(png_structp png_ptr, png_bytep new_row, png_uint_32 row_num, int pass)
michael@0 29 {
michael@0 30 MOZ_ASSERT(sTextureFormat == SurfaceFormat::B8G8R8A8);
michael@0 31
michael@0 32 DataSourceSurface::MappedSurface map = static_cast<TextRenderer*>(png_get_progressive_ptr(png_ptr))->GetSurfaceMap();
michael@0 33
michael@0 34 uint32_t* dst = (uint32_t*)(map.mData + map.mStride * row_num);
michael@0 35
michael@0 36 for (uint32_t x = 0; x < sTextureWidth; x++) {
michael@0 37 // We blend to a transparent white background, this will make text readable
michael@0 38 // even if it's on a dark background. Without hurting our ability to
michael@0 39 // interact with the content behind the text.
michael@0 40 Float alphaValue = Float(0xFF - new_row[x]) / 255.0f;
michael@0 41 Float baseValue = sBackgroundOpacity * (1.0f - alphaValue);
michael@0 42 Color pixelColor(baseValue, baseValue, baseValue, baseValue + alphaValue);
michael@0 43 dst[x] = pixelColor.ToABGR();
michael@0 44 }
michael@0 45 }
michael@0 46
michael@0 47 TextRenderer::~TextRenderer()
michael@0 48 {
michael@0 49 if (mGlyphBitmaps) {
michael@0 50 mGlyphBitmaps->Unmap();
michael@0 51 }
michael@0 52 }
michael@0 53
michael@0 54 void
michael@0 55 TextRenderer::RenderText(const string& aText, const IntPoint& aOrigin,
michael@0 56 const Matrix4x4& aTransform, uint32_t aTextSize,
michael@0 57 uint32_t aTargetPixelWidth)
michael@0 58 {
michael@0 59 EnsureInitialized();
michael@0 60
michael@0 61 // For now we only have a bitmap font with a 16px cell size, so we just
michael@0 62 // scale it up if the user wants larger text.
michael@0 63 Float scaleFactor = Float(aTextSize) / Float(sCellHeight);
michael@0 64
michael@0 65 aTargetPixelWidth /= scaleFactor;
michael@0 66
michael@0 67 uint32_t numLines = 1;
michael@0 68 uint32_t maxWidth = 0;
michael@0 69 uint32_t lineWidth = 0;
michael@0 70 // Calculate the size of the surface needed to draw all the glyphs.
michael@0 71 for (uint32_t i = 0; i < aText.length(); i++) {
michael@0 72 // Insert a line break if we go past the TargetPixelWidth.
michael@0 73 // XXX - this has the downside of overrunning the intended width, causing
michael@0 74 // things at the edge of a window to be cut off.
michael@0 75 if (aText[i] == '\n' || (aText[i] == ' ' && lineWidth > aTargetPixelWidth)) {
michael@0 76 numLines++;
michael@0 77 lineWidth = 0;
michael@0 78 continue;
michael@0 79 }
michael@0 80
michael@0 81 lineWidth += sGlyphWidths[uint32_t(aText[i])];
michael@0 82 maxWidth = std::max(lineWidth, maxWidth);
michael@0 83 }
michael@0 84
michael@0 85 // Create a surface to draw our glyphs to.
michael@0 86 RefPtr<DataSourceSurface> textSurf =
michael@0 87 Factory::CreateDataSourceSurface(IntSize(maxWidth, numLines * sCellHeight), sTextureFormat);
michael@0 88
michael@0 89 DataSourceSurface::MappedSurface map;
michael@0 90 textSurf->Map(DataSourceSurface::MapType::READ_WRITE, &map);
michael@0 91
michael@0 92 // Initialize the surface to transparent white.
michael@0 93 memset(map.mData, uint8_t(sBackgroundOpacity * 255.0f),
michael@0 94 numLines * sCellHeight * map.mStride);
michael@0 95
michael@0 96 uint32_t currentXPos = 0;
michael@0 97 uint32_t currentYPos = 0;
michael@0 98
michael@0 99 // Copy our glyphs onto the surface.
michael@0 100 for (uint32_t i = 0; i < aText.length(); i++) {
michael@0 101 if (aText[i] == '\n' || (aText[i] == ' ' && currentXPos > aTargetPixelWidth)) {
michael@0 102 currentYPos += sCellHeight;
michael@0 103 currentXPos = 0;
michael@0 104 continue;
michael@0 105 }
michael@0 106
michael@0 107 uint32_t glyphXOffset = aText[i] % (sTextureWidth / sCellWidth) * sCellWidth * BytesPerPixel(sTextureFormat);
michael@0 108 uint32_t truncatedLine = aText[i] / (sTextureWidth / sCellWidth);
michael@0 109 uint32_t glyphYOffset = truncatedLine * sCellHeight * mMap.mStride;
michael@0 110
michael@0 111 for (int y = 0; y < 16; y++) {
michael@0 112 memcpy(map.mData + (y + currentYPos) * map.mStride + currentXPos * BytesPerPixel(sTextureFormat),
michael@0 113 mMap.mData + glyphYOffset + y * mMap.mStride + glyphXOffset,
michael@0 114 sGlyphWidths[uint32_t(aText[i])] * BytesPerPixel(sTextureFormat));
michael@0 115 }
michael@0 116
michael@0 117 currentXPos += sGlyphWidths[uint32_t(aText[i])];
michael@0 118 }
michael@0 119
michael@0 120 textSurf->Unmap();
michael@0 121
michael@0 122 RefPtr<DataTextureSource> src = mCompositor->CreateDataTextureSource();
michael@0 123
michael@0 124 if (!src->Update(textSurf)) {
michael@0 125 // Upload failed.
michael@0 126 return;
michael@0 127 }
michael@0 128
michael@0 129 RefPtr<EffectRGB> effect = new EffectRGB(src, true, Filter::LINEAR);
michael@0 130 EffectChain chain;
michael@0 131 chain.mPrimaryEffect = effect;
michael@0 132
michael@0 133 Matrix4x4 transform = aTransform;
michael@0 134 transform.Scale(scaleFactor, scaleFactor, 1.0f);
michael@0 135 mCompositor->DrawQuad(Rect(aOrigin.x, aOrigin.y, maxWidth, numLines * 16),
michael@0 136 Rect(-10000, -10000, 20000, 20000), chain, 1.0f, transform);
michael@0 137 }
michael@0 138
michael@0 139 void
michael@0 140 TextRenderer::EnsureInitialized()
michael@0 141 {
michael@0 142 if (mGlyphBitmaps) {
michael@0 143 return;
michael@0 144 }
michael@0 145
michael@0 146 mGlyphBitmaps = Factory::CreateDataSourceSurface(IntSize(sTextureWidth, sTextureHeight), sTextureFormat);
michael@0 147
michael@0 148 mGlyphBitmaps->Map(DataSourceSurface::MapType::READ_WRITE, &mMap);
michael@0 149
michael@0 150 png_structp png_ptr = NULL;
michael@0 151 png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
michael@0 152
michael@0 153 png_set_progressive_read_fn(png_ptr, this, info_callback, row_callback, nullptr);
michael@0 154 png_infop info_ptr = NULL;
michael@0 155 info_ptr = png_create_info_struct(png_ptr);
michael@0 156
michael@0 157 png_process_data(png_ptr, info_ptr, (uint8_t*)sFontPNG, sizeof(sFontPNG));
michael@0 158
michael@0 159 png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
michael@0 160 }
michael@0 161
michael@0 162 }
michael@0 163 }

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