Use more switch statements in CFX_ScanlineCompositor
Change CompositeBitMaskLine() and CompositeByteMaskLine() to use switch
statements. Then it is easier to see how all cases are being handled.
Add CHECKs to these methods to document the preconditions.
Disallow FXDIB_Format::kInvalid in Init(), as it is never going to get
handled.
Change-Id: I0175c9d00bb5607613dfc16ef9f30d31dc5a070a
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/121372
Reviewed-by: Tom Sepez <tsepez@google.com>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
diff --git a/core/fxge/dib/cfx_scanlinecompositor.cpp b/core/fxge/dib/cfx_scanlinecompositor.cpp
index 2b5f0c0..8e6184b 100644
--- a/core/fxge/dib/cfx_scanlinecompositor.cpp
+++ b/core/fxge/dib/cfx_scanlinecompositor.cpp
@@ -12,6 +12,7 @@
#include "core/fxcrt/check_op.h"
#include "core/fxcrt/compiler_specific.h"
#include "core/fxcrt/fx_memcpy_wrappers.h"
+#include "core/fxcrt/notreached.h"
#include "core/fxcrt/stl_util.h"
#include "core/fxge/dib/blend.h"
#include "core/fxge/dib/fx_dib.h"
@@ -2233,7 +2234,8 @@
m_BlendType = blend_type;
m_bRgbByteOrder = bRgbByteOrder;
m_bClip = bClip;
- if (m_DestFormat == FXDIB_Format::k1bppMask ||
+ if (m_DestFormat == FXDIB_Format::kInvalid ||
+ m_DestFormat == FXDIB_Format::k1bppMask ||
m_DestFormat == FXDIB_Format::k1bppRgb) {
return false;
}
@@ -2323,8 +2325,8 @@
m_SrcFormat == FXDIB_Format::kRgb32 ||
m_SrcFormat == FXDIB_Format::kArgb);
- int src_Bpp = GetCompsFromFormat(m_SrcFormat);
- int dest_Bpp = GetCompsFromFormat(m_DestFormat);
+ const int src_Bpp = GetCompsFromFormat(m_SrcFormat);
+ const int dest_Bpp = GetCompsFromFormat(m_DestFormat);
if (m_bRgbByteOrder) {
if (m_SrcFormat == FXDIB_Format::kArgb) {
if (m_DestFormat == FXDIB_Format::kArgb) {
@@ -2552,49 +2554,53 @@
pdfium::span<const uint8_t> src_scan,
int width,
pdfium::span<const uint8_t> clip_scan) const {
- if (m_DestFormat == FXDIB_Format::k8bppMask) {
- CompositeRow_ByteMask2Mask(dest_scan, src_scan, m_MaskAlpha, width,
- clip_scan);
- return;
- }
- if (m_DestFormat == FXDIB_Format::k8bppRgb) {
- CompositeRow_ByteMask2Gray(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
- width, clip_scan);
- return;
- }
+ CHECK_EQ(m_SrcFormat, FXDIB_Format::k8bppMask);
- // TODO(thestig): Tighten this check.
- DCHECK_NE(GetBppFromFormat(m_DestFormat), 8);
-
- if (m_bRgbByteOrder) {
- if (m_DestFormat == FXDIB_Format::kArgb) {
- CompositeRow_ByteMask2Argb_RgbByteOrder(
- dest_scan, src_scan, m_MaskAlpha, m_MaskRed, m_MaskGreen, m_MaskBlue,
- width, m_BlendType, clip_scan);
- } else {
- CompositeRow_ByteMask2Rgb_RgbByteOrder(
- dest_scan, src_scan, m_MaskAlpha, m_MaskRed, m_MaskGreen, m_MaskBlue,
- width, m_BlendType, GetCompsFromFormat(m_DestFormat), clip_scan);
+ switch (m_DestFormat) {
+ case FXDIB_Format::kInvalid:
+ case FXDIB_Format::k1bppRgb:
+ case FXDIB_Format::k1bppMask: {
+ NOTREACHED_NORETURN(); // Disallowed by Init().
}
- return;
+ case FXDIB_Format::k8bppRgb: {
+ CHECK(!m_bRgbByteOrder); // Disallowed by Init();
+ CompositeRow_ByteMask2Gray(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
+ width, clip_scan);
+ return;
+ }
+ case FXDIB_Format::k8bppMask: {
+ CHECK(!m_bRgbByteOrder); // Disallowed by Init();
+ CompositeRow_ByteMask2Mask(dest_scan, src_scan, m_MaskAlpha, width,
+ clip_scan);
+ return;
+ }
+ case FXDIB_Format::kRgb:
+ case FXDIB_Format::kRgb32: {
+ if (m_bRgbByteOrder) {
+ CompositeRow_ByteMask2Rgb_RgbByteOrder(
+ dest_scan, src_scan, m_MaskAlpha, m_MaskRed, m_MaskGreen,
+ m_MaskBlue, width, m_BlendType, GetCompsFromFormat(m_DestFormat),
+ clip_scan);
+ return;
+ }
+ CompositeRow_ByteMask2Rgb(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
+ m_MaskGreen, m_MaskBlue, width, m_BlendType,
+ GetCompsFromFormat(m_DestFormat), clip_scan);
+ return;
+ }
+ case FXDIB_Format::kArgb: {
+ if (m_bRgbByteOrder) {
+ CompositeRow_ByteMask2Argb_RgbByteOrder(
+ dest_scan, src_scan, m_MaskAlpha, m_MaskRed, m_MaskGreen,
+ m_MaskBlue, width, m_BlendType, clip_scan);
+ return;
+ }
+ CompositeRow_ByteMask2Argb(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
+ m_MaskGreen, m_MaskBlue, width, m_BlendType,
+ clip_scan);
+ return;
+ }
}
-
- if (m_DestFormat == FXDIB_Format::kArgb) {
- CompositeRow_ByteMask2Argb(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
- m_MaskGreen, m_MaskBlue, width, m_BlendType,
- clip_scan);
- return;
- }
-
- if (m_DestFormat == FXDIB_Format::kRgb ||
- m_DestFormat == FXDIB_Format::kRgb32) {
- CompositeRow_ByteMask2Rgb(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
- m_MaskGreen, m_MaskBlue, width, m_BlendType,
- GetCompsFromFormat(m_DestFormat), clip_scan);
- return;
- }
-
- // TODO(thestig): Is this line reachable?
}
void CFX_ScanlineCompositor::CompositeBitMaskLine(
@@ -2603,52 +2609,54 @@
int src_left,
int width,
pdfium::span<const uint8_t> clip_scan) const {
- if (m_DestFormat == FXDIB_Format::k8bppMask) {
- CompositeRow_BitMask2Mask(dest_scan, src_scan, m_MaskAlpha, src_left, width,
- clip_scan);
- return;
- }
+ CHECK_EQ(m_SrcFormat, FXDIB_Format::k1bppMask);
- if (m_DestFormat == FXDIB_Format::k8bppRgb) {
- CompositeRow_BitMask2Gray(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
- src_left, width, clip_scan);
- return;
- }
-
- // TODO(thestig): Tighten this check.
- DCHECK_NE(GetBppFromFormat(m_DestFormat), 8);
-
- if (m_bRgbByteOrder) {
- if (m_DestFormat == FXDIB_Format::kArgb) {
- CompositeRow_BitMask2Argb_RgbByteOrder(
- dest_scan, src_scan, m_MaskAlpha, m_MaskRed, m_MaskGreen, m_MaskBlue,
- src_left, width, m_BlendType, clip_scan);
- } else {
- CompositeRow_BitMask2Rgb_RgbByteOrder(
- dest_scan, src_scan, m_MaskAlpha, m_MaskRed, m_MaskGreen, m_MaskBlue,
- src_left, width, m_BlendType, GetCompsFromFormat(m_DestFormat),
- clip_scan);
+ switch (m_DestFormat) {
+ case FXDIB_Format::kInvalid:
+ case FXDIB_Format::k1bppRgb:
+ case FXDIB_Format::k1bppMask: {
+ NOTREACHED_NORETURN(); // Disallowed by Init().
}
- return;
+ case FXDIB_Format::k8bppRgb: {
+ CHECK(!m_bRgbByteOrder); // Disallowed by Init();
+ CompositeRow_BitMask2Gray(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
+ src_left, width, clip_scan);
+ return;
+ }
+ case FXDIB_Format::k8bppMask: {
+ CHECK(!m_bRgbByteOrder); // Disallowed by Init();
+ CompositeRow_BitMask2Mask(dest_scan, src_scan, m_MaskAlpha, src_left,
+ width, clip_scan);
+ return;
+ }
+ case FXDIB_Format::kRgb:
+ case FXDIB_Format::kRgb32: {
+ if (m_bRgbByteOrder) {
+ CompositeRow_BitMask2Rgb_RgbByteOrder(
+ dest_scan, src_scan, m_MaskAlpha, m_MaskRed, m_MaskGreen,
+ m_MaskBlue, src_left, width, m_BlendType,
+ GetCompsFromFormat(m_DestFormat), clip_scan);
+ return;
+ }
+ CompositeRow_BitMask2Rgb(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
+ m_MaskGreen, m_MaskBlue, src_left, width,
+ m_BlendType, GetCompsFromFormat(m_DestFormat),
+ clip_scan);
+ return;
+ }
+ case FXDIB_Format::kArgb: {
+ if (m_bRgbByteOrder) {
+ CompositeRow_BitMask2Argb_RgbByteOrder(
+ dest_scan, src_scan, m_MaskAlpha, m_MaskRed, m_MaskGreen,
+ m_MaskBlue, src_left, width, m_BlendType, clip_scan);
+ return;
+ }
+ CompositeRow_BitMask2Argb(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
+ m_MaskGreen, m_MaskBlue, src_left, width,
+ m_BlendType, clip_scan);
+ return;
+ }
}
-
- if (m_DestFormat == FXDIB_Format::kArgb) {
- CompositeRow_BitMask2Argb(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
- m_MaskGreen, m_MaskBlue, src_left, width,
- m_BlendType, clip_scan);
- return;
- }
-
- if (m_DestFormat == FXDIB_Format::kRgb ||
- m_DestFormat == FXDIB_Format::kRgb32) {
- CompositeRow_BitMask2Rgb(dest_scan, src_scan, m_MaskAlpha, m_MaskRed,
- m_MaskGreen, m_MaskBlue, src_left, width,
- m_BlendType, GetCompsFromFormat(m_DestFormat),
- clip_scan);
- return;
- }
-
- // TODO(thestig): Is this line reachable?
}
CFX_ScanlineCompositor::Palette::Palette() = default;
