simplify/unify xferproc api

gm/xfer4f.cpp

-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "gm.h"
-#include "SkCanvas.h"
-#include "SkImageInfo.h"
-#include "SkXfermode.h"
-#include "SkPM4f.h"
-
-static void draw_rect(SkCanvas* canvas, const SkRect& r, SkColor c, SkColorProfileType profile,
-                      const SkAlpha aa[]) {
-    const SkIRect ir = r.round();
-
-    SkBitmap bm;
-    bm.allocN32Pixels(ir.width(), ir.height());
-    bm.eraseColor(0xFFFFFFFF);
-    SkPixmap pm;
-    bm.peekPixels(&pm);
-
-    uint32_t flags = 0;
-    if (SkColorGetA(c) == 0xFF) {
-        flags |= SkXfermode::kSrcIsOpaque_PM4fFlag;
-    }
-    if (kSRGB_SkColorProfileType == profile) {
-        flags |= SkXfermode::kDstIsSRGB_PM4fFlag;
-    }
-
-    const SkXfermode::PM4fState state { nullptr, flags };
-
-    const SkPM4f src = SkColor4f::FromColor(c).premul();
-    auto proc1 = SkXfermode::GetPM4fProc1(SkXfermode::kSrcOver_Mode, flags);
-    for (int y = 0; y < ir.height()/2; ++y) {
-        proc1(state, pm.writable_addr32(0, y), src, ir.width(), aa);
-    }
-
-    SkPM4f srcRow[1000];
-    for (int i = 0; i < ir.width(); ++i) {
-        srcRow[i] = src;
-    }
-    auto procN = SkXfermode::GetPM4fProcN(SkXfermode::kSrcOver_Mode, flags);
-    // +1 to skip a row, so we can see the boundary between proc1 and procN
-    for (int y = ir.height()/2 + 1; y < ir.height(); ++y) {
-        procN(state, pm.writable_addr32(0, y), srcRow, ir.width(), aa);
-    }
-
-    canvas->drawBitmap(bm, r.left(), r.top(), nullptr);
-}
-
-/*
- *  Test SkXfer4fProcs directly for src-over, comparing them to current SkColor blits.
- */
-DEF_SIMPLE_GM(xfer4f_srcover, canvas, 580, 760) {
-    const int IW = 50;
-    const SkScalar W = IW;
-    const SkScalar H = 100;
-
-    const int profiles[] = {
-        -1,
-        kLinear_SkColorProfileType,
-        kSRGB_SkColorProfileType,
-    };
-    const SkColor colors[] = {
-        SK_ColorBLACK, SK_ColorRED, SK_ColorGREEN, SK_ColorBLUE,
-        0x88000000, 0x88FF0000, 0x8800FF00, 0x880000FF
-    };
-    
-    uint8_t aa_scanline[IW];
-    for (int i = 0; i < IW; ++i) {
-        aa_scanline[i] = i * 255 / (IW - 1);
-    }
-    uint8_t const* aa_table[] = { nullptr, aa_scanline };
-
-    SkBitmap mask;
-    mask.installPixels(SkImageInfo::MakeA8(IW, 1), aa_scanline, IW);
-
-    canvas->translate(20, 20);
-
-    const SkRect r = SkRect::MakeWH(W, H);
-    for (const uint8_t* aa : aa_table) {
-        canvas->save();
-        for (auto profile : profiles) {
-            canvas->save();
-            for (SkColor c : colors) {
-                if (profile < 0) {
-                    SkPaint p;
-                    p.setColor(c);
-                    if (aa) {
-                        canvas->drawBitmapRect(mask, r, &p);
-                    } else {
-                        canvas->drawRect(r, p);
-                    }
-                } else {
-                    draw_rect(canvas, r, c, (SkColorProfileType)profile, aa);
-                }
-                canvas->translate(W + 20, 0);
-            }
-            canvas->restore();
-            canvas->translate(0, H + 20);
-        }
-        canvas->restore();
-        canvas->translate(0, (H + 20) * SK_ARRAY_COUNT(profiles) + 20);
-    }
-}