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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "TextRenderer.h"
#include "FontData.h"
#include "png.h"
#include "mozilla/Base64.h"
#include "mozilla/layers/Compositor.h"
#include "mozilla/layers/TextureHost.h"
#include "mozilla/layers/Effects.h"
namespace mozilla {
namespace layers {
using namespace gfx;
using namespace std;
const Float sBackgroundOpacity = 0.6f;
const SurfaceFormat sTextureFormat = SurfaceFormat::B8G8R8A8;
static void PNGAPI info_callback(png_structp png_ptr, png_infop info_ptr)
{
png_read_update_info(png_ptr, info_ptr);
}
static void PNGAPI row_callback(png_structp png_ptr, png_bytep new_row, png_uint_32 row_num, int pass)
{
MOZ_ASSERT(sTextureFormat == SurfaceFormat::B8G8R8A8);
DataSourceSurface::MappedSurface map = static_cast<TextRenderer*>(png_get_progressive_ptr(png_ptr))->GetSurfaceMap();
uint32_t* dst = (uint32_t*)(map.mData + map.mStride * row_num);
for (uint32_t x = 0; x < sTextureWidth; x++) {
// We blend to a transparent white background, this will make text readable
// even if it's on a dark background. Without hurting our ability to
// interact with the content behind the text.
Float alphaValue = Float(0xFF - new_row[x]) / 255.0f;
Float baseValue = sBackgroundOpacity * (1.0f - alphaValue);
Color pixelColor(baseValue, baseValue, baseValue, baseValue + alphaValue);
dst[x] = pixelColor.ToABGR();
}
}
TextRenderer::~TextRenderer()
{
if (mGlyphBitmaps) {
mGlyphBitmaps->Unmap();
}
}
void
TextRenderer::RenderText(const string& aText, const IntPoint& aOrigin,
const Matrix4x4& aTransform, uint32_t aTextSize,
uint32_t aTargetPixelWidth)
{
EnsureInitialized();
// For now we only have a bitmap font with a 16px cell size, so we just
// scale it up if the user wants larger text.
Float scaleFactor = Float(aTextSize) / Float(sCellHeight);
aTargetPixelWidth /= scaleFactor;
uint32_t numLines = 1;
uint32_t maxWidth = 0;
uint32_t lineWidth = 0;
// Calculate the size of the surface needed to draw all the glyphs.
for (uint32_t i = 0; i < aText.length(); i++) {
// Insert a line break if we go past the TargetPixelWidth.
// XXX - this has the downside of overrunning the intended width, causing
// things at the edge of a window to be cut off.
if (aText[i] == '\n' || (aText[i] == ' ' && lineWidth > aTargetPixelWidth)) {
numLines++;
lineWidth = 0;
continue;
}
lineWidth += sGlyphWidths[uint32_t(aText[i])];
maxWidth = std::max(lineWidth, maxWidth);
}
// Create a surface to draw our glyphs to.
RefPtr<DataSourceSurface> textSurf =
Factory::CreateDataSourceSurface(IntSize(maxWidth, numLines * sCellHeight), sTextureFormat);
if (NS_WARN_IF(!textSurf)) {
return;
}
DataSourceSurface::MappedSurface map;
if (NS_WARN_IF(!textSurf->Map(DataSourceSurface::MapType::READ_WRITE, &map))) {
return;
}
// Initialize the surface to transparent white.
memset(map.mData, uint8_t(sBackgroundOpacity * 255.0f),
numLines * sCellHeight * map.mStride);
uint32_t currentXPos = 0;
uint32_t currentYPos = 0;
// Copy our glyphs onto the surface.
for (uint32_t i = 0; i < aText.length(); i++) {
if (aText[i] == '\n' || (aText[i] == ' ' && currentXPos > aTargetPixelWidth)) {
currentYPos += sCellHeight;
currentXPos = 0;
continue;
}
uint32_t glyphXOffset = aText[i] % (sTextureWidth / sCellWidth) * sCellWidth * BytesPerPixel(sTextureFormat);
uint32_t truncatedLine = aText[i] / (sTextureWidth / sCellWidth);
uint32_t glyphYOffset = truncatedLine * sCellHeight * mMap.mStride;
for (int y = 0; y < 16; y++) {
memcpy(map.mData + (y + currentYPos) * map.mStride + currentXPos * BytesPerPixel(sTextureFormat),
mMap.mData + glyphYOffset + y * mMap.mStride + glyphXOffset,
sGlyphWidths[uint32_t(aText[i])] * BytesPerPixel(sTextureFormat));
}
currentXPos += sGlyphWidths[uint32_t(aText[i])];
}
textSurf->Unmap();
RefPtr<DataTextureSource> src = mCompositor->CreateDataTextureSource();
if (!src->Update(textSurf)) {
// Upload failed.
return;
}
RefPtr<EffectRGB> effect = new EffectRGB(src, true, SamplingFilter::LINEAR);
EffectChain chain;
chain.mPrimaryEffect = effect;
Matrix4x4 transform = aTransform;
transform.PreScale(scaleFactor, scaleFactor, 1.0f);
mCompositor->DrawQuad(Rect(aOrigin.x, aOrigin.y, maxWidth, numLines * 16),
IntRect(-10000, -10000, 20000, 20000), chain, 1.0f, transform);
}
void
TextRenderer::EnsureInitialized()
{
if (mGlyphBitmaps) {
return;
}
mGlyphBitmaps = Factory::CreateDataSourceSurface(IntSize(sTextureWidth, sTextureHeight), sTextureFormat);
if (NS_WARN_IF(!mGlyphBitmaps)) {
return;
}
if (NS_WARN_IF(!mGlyphBitmaps->Map(DataSourceSurface::MapType::READ_WRITE, &mMap))) {
return;
}
png_structp png_ptr = NULL;
png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr, nullptr, nullptr);
png_set_progressive_read_fn(png_ptr, this, info_callback, row_callback, nullptr);
png_infop info_ptr = NULL;
info_ptr = png_create_info_struct(png_ptr);
png_process_data(png_ptr, info_ptr, (uint8_t*)sFontPNG, sizeof(sFontPNG));
png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
}
} // namespace layers
} // namespace mozilla
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