Initial error handling code

src/core/SkXfermode.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkXfermode.h"
 #include "SkColorPriv.h"
 #include "SkFlattenableBuffers.h"
 #include "SkMathPriv.h"
 #include "SkString.h"
+#include "SkValidationUtils.h"
 
 SK_DEFINE_INST_COUNT(SkXfermode)
 
 #define SkAlphaMulAlpha(a, b)   SkMulDiv255Round(a, b)
 
 #if 0
 // idea for higher precision blends in xfer procs (and slightly faster)
 // see DstATop as a probable caller
 static U8CPU mulmuldiv255round(U8CPU a, U8CPU b, U8CPU c, U8CPU d) {
     SkASSERT(a <= 255);
@@ skipping 1343 matching lines @@
     static AutoEffectUnref gEffect(SkNEW_ARGS(XferEffect, (static_cast<SkXfermode::Mode>(mode), NULL)));
     return CreateEffectRef(gEffect);
 }
 
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
 ///////////////////////////////////////////////////////////////////////////////
 
 class SkProcCoeffXfermode : public SkProcXfermode {
+    typedef SkProcXfermode INHERITED;
+
 public:
     SkProcCoeffXfermode(const ProcCoeff& rec, Mode mode)
             : INHERITED(rec.fProc) {
         fMode = mode;
         // these may be valid, or may be CANNOT_USE_COEFF
         fSrcCoeff = rec.fSC;
         fDstCoeff = rec.fDC;
     }
 
     virtual bool asMode(Mode* mode) const SK_OVERRIDE {
@@ skipping 43 matching lines @@
 protected:
     SkProcCoeffXfermode(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {
         fMode = (SkXfermode::Mode)buffer.read32();
 
         const ProcCoeff& rec = gProcCoeffs[fMode];
         // these may be valid, or may be CANNOT_USE_COEFF
         fSrcCoeff = rec.fSC;
         fDstCoeff = rec.fDC;
         // now update our function-ptr in the super class
         this->INHERITED::setProc(rec.fProc);
+
+        buffer.validate(SkIsValidMode(fMode) &&
+                        SkIsValidCoeff(fSrcCoeff) &&
+                        SkIsValidCoeff(fDstCoeff));
     }
 
     virtual void flatten(SkFlattenableWriteBuffer& buffer) const SK_OVERRIDE {
         this->INHERITED::flatten(buffer);
         buffer.write32(fMode);
     }
 
 private:
     Mode    fMode;
     Coeff   fSrcCoeff, fDstCoeff;
-
-    typedef SkProcXfermode INHERITED;
 };
 
 const char* SkXfermode::ModeName(Mode mode) {
     SkASSERT((unsigned) mode <= (unsigned)kLastMode);
     const char* gModeStrings[] = {
         "Clear", "Src", "Dst", "SrcOver", "DstOver", "SrcIn", "DstIn",
         "SrcOut", "DstOut", "SrcATop", "DstATop", "Xor", "Plus",
         "Modulate", "Screen", "Overlay", "Darken", "Lighten", "ColorDodge",
         "ColorBurn", "HardLight", "SoftLight", "Difference", "Exclusion",
         "Multiply", "Hue", "Saturation", "Color",  "Luminosity"
@@ skipping 25 matching lines @@
         str->append("can't use");
     } else {
         str->append(gCoeffStrings[fDstCoeff]);
     }
 }
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
 
 class SkClearXfermode : public SkProcCoeffXfermode {
+    typedef SkProcCoeffXfermode INHERITED;
+
 public:
     SkClearXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kClear_Mode) {}
 
     virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
     virtual void xferA8(SkAlpha*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
 
     SK_DEVELOPER_TO_STRING()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkClearXfermode)
 
 private:
     SkClearXfermode(SkFlattenableReadBuffer& buffer)
         : SkProcCoeffXfermode(buffer) {}
-
-    typedef SkProcCoeffXfermode INHERITED;
 };
 
 void SkClearXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                              const SkPMColor* SK_RESTRICT, int count,
                              const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && count >= 0);
 
     if (NULL == aa) {
         memset(dst, 0, count << 2);
     } else {
@@ skipping 28 matching lines @@
 
 #ifdef SK_DEVELOPER
 void SkClearXfermode::toString(SkString* str) const {
     this->INHERITED::toString(str);
 }
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
 
 class SkSrcXfermode : public SkProcCoeffXfermode {
+    typedef SkProcCoeffXfermode INHERITED;
+
 public:
     SkSrcXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kSrc_Mode) {}
 
     virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
     virtual void xferA8(SkAlpha*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
 
     SK_DEVELOPER_TO_STRING()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkSrcXfermode)
 
 private:
     SkSrcXfermode(SkFlattenableReadBuffer& buffer)
         : SkProcCoeffXfermode(buffer) {}
-
-    typedef SkProcCoeffXfermode INHERITED;
 };
 
 void SkSrcXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                            const SkPMColor* SK_RESTRICT src, int count,
                            const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src && count >= 0);
 
     if (NULL == aa) {
         memcpy(dst, src, count << 2);
     } else {
@@ skipping 33 matching lines @@
 }
 #ifdef SK_DEVELOPER
 void SkSrcXfermode::toString(SkString* str) const {
     this->INHERITED::toString(str);
 }
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
 
 class SkDstInXfermode : public SkProcCoeffXfermode {
+    typedef SkProcCoeffXfermode INHERITED;
+
 public:
     SkDstInXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kDstIn_Mode) {}
 
     virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
 
     SK_DEVELOPER_TO_STRING()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDstInXfermode)
 
 private:
     SkDstInXfermode(SkFlattenableReadBuffer& buffer) : INHERITED(buffer) {}
-
-    typedef SkProcCoeffXfermode INHERITED;
 };
 
 void SkDstInXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                              const SkPMColor* SK_RESTRICT src, int count,
                              const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src);
 
     if (count <= 0) {
         return;
     }
@@ skipping 11 matching lines @@
 
 #ifdef SK_DEVELOPER
 void SkDstInXfermode::toString(SkString* str) const {
     this->INHERITED::toString(str);
 }
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
 
 class SkDstOutXfermode : public SkProcCoeffXfermode {
+    typedef SkProcCoeffXfermode INHERITED;
+
 public:
     SkDstOutXfermode(const ProcCoeff& rec) : SkProcCoeffXfermode(rec, kDstOut_Mode) {}
 
     virtual void xfer32(SkPMColor*, const SkPMColor*, int, const SkAlpha*) const SK_OVERRIDE;
 
     SK_DEVELOPER_TO_STRING()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDstOutXfermode)
 
 private:
     SkDstOutXfermode(SkFlattenableReadBuffer& buffer)
         : INHERITED(buffer) {}
-
-    typedef SkProcCoeffXfermode INHERITED;
 };
 
 void SkDstOutXfermode::xfer32(SkPMColor* SK_RESTRICT dst,
                               const SkPMColor* SK_RESTRICT src, int count,
                               const SkAlpha* SK_RESTRICT aa) const {
     SkASSERT(dst && src);
 
     if (count <= 0) {
         return;
     }
@@ skipping 10 matching lines @@
 }
 
 #ifdef SK_DEVELOPER
 void SkDstOutXfermode::toString(SkString* str) const {
     this->INHERITED::toString(str);
 }
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
 
+SkFlattenable::Factory SkProcXfermode::GetFactory(SkFlattenable::Type type) {
+    switch(type) {
+    case SkFlattenable::kSkClearXfermode:
+        return SkClearXfermode::CreateProc;
+    case SkFlattenable::kSkDstInXfermode:
+        return SkDstInXfermode::CreateProc;
+    case SkFlattenable::kSkDstOutXfermode:
+        return SkDstOutXfermode::CreateProc;
+    case SkFlattenable::kSkProcCoeffXfermode:
+        return SkProcCoeffXfermode::CreateProc;
+    case SkFlattenable::kSkSrcXfermode:
+        return SkSrcXfermode::CreateProc;
+    default:
+        break;
+    }
+    return NULL;
+}
+
+SkFlattenable::TypeCheck SkProcXfermode::GetTypeCheck(SkFlattenable::Type type) {
+    switch(type) {
+    case SkFlattenable::kSkClearXfermode:
+        return SkClearXfermode::IsA;
+    case SkFlattenable::kSkDstInXfermode:
+        return SkDstInXfermode::IsA;
+    case SkFlattenable::kSkDstOutXfermode:
+        return SkDstOutXfermode::IsA;
+    case SkFlattenable::kSkProcCoeffXfermode:
+        return SkProcCoeffXfermode::IsA;
+    case SkFlattenable::kSkSrcXfermode:
+        return SkSrcXfermode::IsA;
+    default:
+        break;
+    }
+    return NULL;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
 SkXfermode* SkXfermode::Create(Mode mode) {
     SkASSERT(SK_ARRAY_COUNT(gProcCoeffs) == kModeCount);
     SkASSERT((unsigned)mode < kModeCount);
 
     const ProcCoeff& rec = gProcCoeffs[mode];
 
     switch (mode) {
         case kClear_Mode:
             return SkNEW_ARGS(SkClearXfermode, (rec));
         case kSrc_Mode:
@@ skipping 240 matching lines @@
     return proc16;
 }
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkProcCoeffXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkClearXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkSrcXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkDstInXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkDstOutXfermode)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END