Use float rather than SkFixed for gradient TileProcs.

tests/ClampRangeTest.cpp

-/*
- * 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 "SkRandom.h"
-#include "Test.h"
-#include "gradients/SkClampRange.h"
-
-static skiatest::Reporter* gReporter;
-#define R_ASSERT(cond) if (!(cond)) {      \
-    SkDebugf("%d: %s\n", __LINE__, #cond); \
-    REPORTER_ASSERT(gReporter, cond);      \
-}
-
-// Arbitrary sentinel values outside [0, 0xFFFF].
-static const int kV0 = -42, kV1 = -53, kRamp = -64;
-
-static void check_value(int64_t bigfx, int expected) {
-    if (bigfx < 0) {
-        R_ASSERT(expected == kV0);
-    } else if (bigfx > kFracMax_SkGradFixed) {
-        R_ASSERT(expected == kV1);
-    } else if (bigfx == kFracMax_SkGradFixed) {
-        // Either one is fine (and we do see both).
-        R_ASSERT(expected == kV1 || expected == kRamp);
-    } else {
-        R_ASSERT(expected == kRamp);
-    }
-}
-
-static void slow_check(const SkClampRange& range,
-                       const SkGradFixed fx, SkGradFixed dx, int count) {
-    SkASSERT(range.fCount0 + range.fCount1 + range.fCount2 == count);
-
-    // If dx is large, fx will overflow if updated naively.  So we use more bits.
-    int64_t bigfx = fx;
-
-    for (int i = 0; i < range.fCount0; i++) {
-        check_value(bigfx, range.fV0);
-        bigfx += dx;
-    }
-
-    for (int i = 0; i < range.fCount1; i++) {
-        check_value(bigfx, kRamp);
-        bigfx += dx;
-    }
-
-    for (int i = 0; i < range.fCount2; i++) {
-        check_value(bigfx, range.fV1);
-        bigfx += dx;
-    }
-}
-
-
-static void test_range(SkFixed fx, SkFixed dx, int count) {
-    const SkGradFixed gfx = SkFixedToGradFixed(fx);
-    const SkGradFixed gdx = SkFixedToGradFixed(dx);
-
-    SkClampRange range;
-    range.init(gfx, gdx, count, kV0, kV1);
-    slow_check(range, gfx, gdx, count);
-}
-
-#define ff(x)   SkIntToFixed(x)
-
-DEF_TEST(ClampRange, reporter) {
-    gReporter = reporter;
-
-    test_range(0, 0, 20);
-    test_range(0xFFFF, 0, 20);
-    test_range(-ff(2), 0, 20);
-    test_range( ff(2), 0, 20);
-
-    test_range(-10, 1, 20);
-    test_range(10, -1, 20);
-    test_range(-10, 3, 20);
-    test_range(10, -3, 20);
-
-    test_range(ff(1),  ff(16384),  100);
-    test_range(ff(-1), ff(-16384), 100);
-    test_range(ff(1)/2, ff(16384), 100);
-    test_range(ff(1)/2, ff(-16384), 100);
-
-    SkRandom rand;
-
-    // test non-overflow cases
-    for (int i = 0; i < 1000000; i++) {
-        SkFixed fx = rand.nextS() >> 1;
-        SkFixed sx = rand.nextS() >> 1;
-        int count = rand.nextU() % 1000 + 1;
-        SkFixed dx = (sx - fx) / count;
-        test_range(fx, dx, count);
-    }
-
-    // TODO(reed): skia:2481, fix whatever bug this is, then uncomment
-    /*
-    // test overflow cases
-    for (int i = 0; i < 100000; i++) {
-        SkFixed fx = rand.nextS();
-        SkFixed dx = rand.nextS();
-        int count = rand.nextU() % 1000 + 1;
-        test_range(fx, dx, count);
-    }
-    */
-}