make SkXfermode.h go away

This is step one:
- make SkXfermode useless to public clients
- everything they should need is in SkBlendMode.h

Step two:
- remove SkXfermode.h entirely (since skia core will already be using SkXfermodePriv.h)

BUG=skia:

GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=4534

Change-Id: If2cea9f71df92430ed6644edb98dd306c5572cbc
Reviewed-on: https://skia-review.googlesource.com/4534
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>

4 files changed, 2 insertions, 140 deletions

diff --git a/tests/BlendTest.cpp b/tests/BlendTest.cpp
index ca9e46efd3..cd5e8efba7 100644
--- a/tests/BlendTest.cpp
+++ b/tests/BlendTest.cpp
@@ -67,36 +67,3 @@ DEF_TEST(Blend_byte_multiply, r) {
     };
     for (auto multiply : perfect) { REPORTER_ASSERT(r, test(multiply).diffs == 0); }
 }
-
-DEF_TEST(Blend_premul_begets_premul, r) {
-    // This test is quite slow, even if you have enough cores to run each mode in parallel.
-    if (!r->allowExtendedTest()) {
-        return;
-    }
-
-    // No matter what xfermode we use, premul inputs should create premul outputs.
-    auto test_mode = [&](int m) {
-        SkXfermode::Mode mode = (SkXfermode::Mode)m;
-        if (mode == SkXfermode::kSrcOver_Mode) {
-            return;  // TODO: can't create a SrcOver xfermode.
-        }
-        auto xfermode(SkXfermode::Make(mode));
-        SkASSERT(xfermode);
-        // We'll test all alphas and legal color values, assuming all colors work the same.
-        // This is not true for non-separable blend modes, but this test still can't hurt.
-        for (int sa = 0; sa <= 255; sa++) {
-        for (int da = 0; da <= 255; da++) {
-        for (int  s = 0;  s <= sa;   s++) {
-        for (int  d = 0;  d <= da;   d++) {
-            SkPMColor src = SkPackARGB32(sa, s, s, s),
-                      dst = SkPackARGB32(da, d, d, d);
-            xfermode->xfer32(&dst, &src, 1, nullptr);  // To keep it simple, no AA.
-            if (!SkPMColorValid(dst)) {
-                ERRORF(r, "%08x is not premul using %s", dst, SkXfermode::ModeName(mode));
-            }
-        }}}}
-    };
-
-    // Parallelism helps speed things up on my desktop from ~725s to ~50s.
-    SkTaskGroup().batch(SkXfermode::kLastMode, test_mode);
-}
diff --git a/tests/RecordingXfermodeTest.cpp b/tests/RecordingXfermodeTest.cpp
index 32aec36f9f..db4262c7e9 100644
--- a/tests/RecordingXfermodeTest.cpp
+++ b/tests/RecordingXfermodeTest.cpp
@@ -12,6 +12,7 @@
 #include "../include/core/SkStream.h"
 #include "../include/core/SkString.h"
 #include "../include/core/SkPictureRecorder.h"
+#include "../src/core/SkBlendModePriv.h"
 #include <cstring>
 
 // Verify that replay of a recording into a clipped canvas
@@ -160,7 +161,7 @@ DEF_TEST(SkRecordingAccuracyXfermode, reporter) {
         if (memcmp(goldenBM.getPixels(), pictureBM.getPixels(), pixelsSize)) {
             numErrors++;
             errors.appendf("For SkXfermode %d %s:    SkPictureRecorder bitmap is wrong\n",
-                           iMode, SkXfermode::ModeName(mode));
+                           iMode, SkBlendMode_Name(mode));
         }
 #endif
     }
diff --git a/tests/SkColor4fTest.cpp b/tests/SkColor4fTest.cpp
index 028b99f413..f268e5f42d 100644
--- a/tests/SkColor4fTest.cpp
+++ b/tests/SkColor4fTest.cpp
@@ -23,15 +23,6 @@ static bool nearly_equal(float a, float b, float tol = kTolerance) {
     return fabsf(a - b) <= tol;
 }
 
-static bool nearly_equal(const SkPM4f a, const SkPM4f& b, float tol = kTolerance) {
-    for (int i = 0; i < 4; ++i) {
-        if (!nearly_equal(a.fVec[i], b.fVec[i], tol)) {
-            return false;
-        }
-    }
-    return true;
-}
-
 DEF_TEST(SkColor4f_FromColor, reporter) {
     const struct {
         SkColor     fC;
@@ -75,45 +66,3 @@ DEF_TEST(Color4f_premul, reporter) {
         REPORTER_ASSERT(reporter, nearly_equal(pm4.b(), c4.fA * c4.fB));
     }
 }
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
-typedef SkPM4f (*SkXfermodeProc4f)(const SkPM4f& src, const SkPM4f& dst);
-
-static bool compare_procs(SkXfermodeProc proc32, SkXfermodeProc4f proc4f) {
-    const float kTolerance = 1.0f / 255;
-
-    const SkColor colors[] = {
-        0, 0xFF000000, 0xFFFFFFFF, 0x80FF0000
-    };
-
-    for (auto s32 : colors) {
-        SkPMColor s_pm32 = SkPreMultiplyColor(s32);
-        SkPM4f    s_pm4f = SkColor4f::FromColor(s32).premul();
-        for (auto d32 : colors) {
-            SkPMColor d_pm32 = SkPreMultiplyColor(d32);
-            SkPM4f    d_pm4f = SkColor4f::FromColor(d32).premul();
-
-            SkPMColor r32 = proc32(s_pm32, d_pm32);
-            SkPM4f    r4f = proc4f(s_pm4f, d_pm4f);
-
-            SkPM4f r32_4f = SkPM4f::FromPMColor(r32);
-            if (!nearly_equal(r4f, r32_4f, kTolerance)) {
-                return false;
-            }
-        }
-    }
-    return true;
-}
-
-// Check that our Proc and Proc4f return (nearly) the same results
-//
-DEF_TEST(Color4f_xfermode_proc4f, reporter) {
-    // TODO: extend xfermodes so that all cases can be tested.
-    //
-    for (int mode = (int)SkBlendMode::kClear; mode <= (int)SkBlendMode::kScreen; ++mode) {
-        SkXfermodeProc   proc32 = SkXfermode::GetProc((SkBlendMode)mode);
-        SkXfermodeProc4f proc4f = SkXfermode::GetProc4f((SkBlendMode)mode);
-        REPORTER_ASSERT(reporter, compare_procs(proc32, proc4f));
-    }
-}
diff --git a/tests/XfermodeTest.cpp b/tests/XfermodeTest.cpp
deleted file mode 100644
index c3a4d96785..0000000000
--- a/tests/XfermodeTest.cpp
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- * Copyright 2011 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkColor.h"
-#include "SkXfermode.h"
-#include "Test.h"
-
-#define ILLEGAL_MODE    ((SkXfermode::Mode)-1)
-
-static void test_asMode(skiatest::Reporter* reporter) {
-    for (int mode = 0; mode <= SkXfermode::kLastMode; mode++) {
-        auto xfer = SkXfermode::Make((SkXfermode::Mode) mode);
-
-        SkXfermode::Mode reportedMode = ILLEGAL_MODE;
-        REPORTER_ASSERT(reporter, reportedMode != mode);
-
-        // test IsMode
-        REPORTER_ASSERT(reporter, SkXfermode::AsMode(xfer, &reportedMode));
-        REPORTER_ASSERT(reporter, reportedMode == mode);
-
-        // repeat that test, but with asMode instead
-        if (xfer) {
-            reportedMode = (SkXfermode::Mode) -1;
-            REPORTER_ASSERT(reporter, xfer->asMode(&reportedMode));
-            REPORTER_ASSERT(reporter, reportedMode == mode);
-        } else {
-            REPORTER_ASSERT(reporter, SkXfermode::kSrcOver_Mode == mode);
-        }
-    }
-}
-
-static void test_IsMode(skiatest::Reporter* reporter) {
-    REPORTER_ASSERT(reporter, SkXfermode::IsMode(nullptr,
-                                                 SkXfermode::kSrcOver_Mode));
-
-    for (int i = 0; i <= SkXfermode::kLastMode; ++i) {
-        SkXfermode::Mode mode = (SkXfermode::Mode)i;
-
-        auto xfer = SkXfermode::Make(mode);
-        REPORTER_ASSERT(reporter, SkXfermode::IsMode(xfer, mode));
-
-        if (SkXfermode::kSrcOver_Mode != mode) {
-            REPORTER_ASSERT(reporter, !SkXfermode::IsMode(nullptr, mode));
-        }
-    }
-}
-
-DEF_TEST(Xfermode, reporter) {
-    test_asMode(reporter);
-    test_IsMode(reporter);
-}