Change CFX_BitmapComposer to use float alpha values
Change a helper class to use float alpha values when possible, and
convert to integer alpha values as-needed.
Change-Id: Ia5b4dbaee22af874524e64000d15fab00091fb2d
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/115416
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/core/fxge/agg/fx_agg_driver.cpp b/core/fxge/agg/fx_agg_driver.cpp
index 6edad47..ef90113 100644
--- a/core/fxge/agg/fx_agg_driver.cpp
+++ b/core/fxge/agg/fx_agg_driver.cpp
@@ -1349,8 +1349,9 @@
FX_RECT dest_clip = dest_rect;
dest_clip.Intersect(*pClipRect);
CFX_BitmapComposer composer;
- composer.Compose(m_pBitmap, m_pClipRgn.get(), 255, argb, dest_clip, false,
- false, false, m_bRgbByteOrder, blend_type);
+ composer.Compose(m_pBitmap, m_pClipRgn.get(), /*alpha=*/1.0f, argb, dest_clip,
+ /*bVertical=*/false, /*bFlipX=*/false, /*bFlipY=*/false,
+ m_bRgbByteOrder, blend_type);
dest_clip.Offset(-dest_rect.left, -dest_rect.top);
CFX_ImageStretcher stretcher(&composer, pSource, dest_width, dest_height,
dest_clip, options);
diff --git a/core/fxge/dib/cfx_bitmapcomposer.cpp b/core/fxge/dib/cfx_bitmapcomposer.cpp
index e924034..30c57c3 100644
--- a/core/fxge/dib/cfx_bitmapcomposer.cpp
+++ b/core/fxge/dib/cfx_bitmapcomposer.cpp
@@ -11,6 +11,7 @@
#include "core/fxcrt/fx_2d_size.h"
#include "core/fxcrt/fx_coordinates.h"
#include "core/fxcrt/fx_safe_types.h"
+#include "core/fxcrt/fx_system.h"
#include "core/fxcrt/span_util.h"
#include "core/fxge/cfx_cliprgn.h"
#include "core/fxge/dib/cfx_dibitmap.h"
@@ -22,7 +23,7 @@
void CFX_BitmapComposer::Compose(const RetainPtr<CFX_DIBitmap>& pDest,
const CFX_ClipRgn* pClipRgn,
- int bitmap_alpha,
+ float alpha,
uint32_t mask_color,
const FX_RECT& dest_rect,
bool bVertical,
@@ -36,7 +37,7 @@
m_DestTop = dest_rect.top;
m_DestWidth = dest_rect.Width();
m_DestHeight = dest_rect.Height();
- m_BitmapAlpha = bitmap_alpha;
+ m_Alpha = alpha;
m_MaskColor = mask_color;
m_pClipMask = nullptr;
if (pClipRgn && pClipRgn->GetType() != CFX_ClipRgn::kRectI)
@@ -57,15 +58,14 @@
m_SrcFormat = src_format;
if (!m_Compositor.Init(m_pBitmap->GetFormat(), src_format, src_palette,
m_MaskColor, m_BlendMode,
- m_pClipMask != nullptr || (m_BitmapAlpha < 255),
- m_bRgbByteOrder)) {
+ m_pClipMask || m_Alpha != 1.0f, m_bRgbByteOrder)) {
return false;
}
if (m_bVertical) {
m_pScanlineV.resize(m_pBitmap->GetBPP() / 8 * width + 4);
m_pClipScanV.resize(m_pBitmap->GetHeight());
}
- if (m_BitmapAlpha < 255) {
+ if (m_Alpha != 1.0f) {
m_pAddClipScan.resize(m_bVertical ? m_pBitmap->GetHeight()
: m_pBitmap->GetWidth());
}
@@ -76,13 +76,14 @@
pdfium::span<const uint8_t> src_scan,
int dest_width,
pdfium::span<const uint8_t> clip_scan) {
- if (m_BitmapAlpha < 255) {
+ if (m_Alpha != 1.0f) {
if (!clip_scan.empty()) {
- for (int i = 0; i < dest_width; ++i)
- m_pAddClipScan[i] = clip_scan[i] * m_BitmapAlpha / 255;
+ for (int i = 0; i < dest_width; ++i) {
+ m_pAddClipScan[i] = clip_scan[i] * m_Alpha;
+ }
} else {
fxcrt::spanset(pdfium::make_span(m_pAddClipScan).first(dest_width),
- m_BitmapAlpha);
+ FXSYS_roundf(m_Alpha * 255));
}
clip_scan = m_pAddClipScan;
}
diff --git a/core/fxge/dib/cfx_bitmapcomposer.h b/core/fxge/dib/cfx_bitmapcomposer.h
index c4cc07d..f63c8c5 100644
--- a/core/fxge/dib/cfx_bitmapcomposer.h
+++ b/core/fxge/dib/cfx_bitmapcomposer.h
@@ -27,7 +27,7 @@
void Compose(const RetainPtr<CFX_DIBitmap>& pDest,
const CFX_ClipRgn* pClipRgn,
- int bitmap_alpha,
+ float alpha,
uint32_t mask_color,
const FX_RECT& dest_rect,
bool bVertical,
@@ -57,7 +57,7 @@
int m_DestTop;
int m_DestWidth;
int m_DestHeight;
- int m_BitmapAlpha;
+ float m_Alpha;
uint32_t m_MaskColor;
RetainPtr<CFX_DIBitmap> m_pClipMask;
CFX_ScanlineCompositor m_Compositor;
diff --git a/core/fxge/dib/cfx_imagerenderer.cpp b/core/fxge/dib/cfx_imagerenderer.cpp
index 592124d..0631018 100644
--- a/core/fxge/dib/cfx_imagerenderer.cpp
+++ b/core/fxge/dib/cfx_imagerenderer.cpp
@@ -49,9 +49,11 @@
bitmap_clip.Offset(-image_rect.left, -image_rect.top);
bitmap_clip = bitmap_clip.SwappedClipBox(dest_width, dest_height,
m_Matrix.c > 0, m_Matrix.b < 0);
- m_Composer.Compose(pDevice, pClipRgn, bitmap_alpha, mask_color, m_ClipBox,
- true, m_Matrix.c > 0, m_Matrix.b < 0, m_bRgbByteOrder,
- BlendMode::kNormal);
+ const bool flip_x = m_Matrix.c > 0;
+ const bool flip_y = m_Matrix.b < 0;
+ m_Composer.Compose(pDevice, pClipRgn, bitmap_alpha / 255.0f, mask_color,
+ m_ClipBox, /*bVertical=*/true, flip_x, flip_y,
+ m_bRgbByteOrder, BlendMode::kNormal);
m_Stretcher = std::make_unique<CFX_ImageStretcher>(
&m_Composer, pSource, dest_height, dest_width, bitmap_clip, options);
if (m_Stretcher->Start())
@@ -77,8 +79,10 @@
FX_RECT bitmap_clip = m_ClipBox;
bitmap_clip.Offset(-image_rect.left, -image_rect.top);
- m_Composer.Compose(pDevice, pClipRgn, bitmap_alpha, mask_color, m_ClipBox,
- false, false, false, m_bRgbByteOrder, BlendMode::kNormal);
+ m_Composer.Compose(pDevice, pClipRgn, bitmap_alpha / 255.0f, mask_color,
+ m_ClipBox,
+ /*bVertical=*/false, /*bFlipX=*/false, /*bFlipY=*/false,
+ m_bRgbByteOrder, BlendMode::kNormal);
m_State = State::kStretching;
m_Stretcher = std::make_unique<CFX_ImageStretcher>(
&m_Composer, pSource, dest_width, dest_height, bitmap_clip, options);
