From 39541080f5e873d4497ac228f731c9d8dfb427eb Mon Sep 17 00:00:00 2001 From: Florin Malita Date: Mon, 18 Sep 2017 12:29:56 -0400 Subject: Delete the legacy linear gradient impl Dead code at this point. Change-Id: I0eb705195446ec084ead49c9f712bf19d8892305 Reviewed-on: https://skia-review.googlesource.com/48020 Reviewed-by: Herb Derby Reviewed-by: Mike Klein Commit-Queue: Mike Klein --- src/shaders/gradients/SkLinearGradient.cpp | 552 ----------------------------- src/shaders/gradients/SkLinearGradient.h | 36 -- 2 files changed, 588 deletions(-) diff --git a/src/shaders/gradients/SkLinearGradient.cpp b/src/shaders/gradients/SkLinearGradient.cpp index 4d3213b47b..04e82825ca 100644 --- a/src/shaders/gradients/SkLinearGradient.cpp +++ b/src/shaders/gradients/SkLinearGradient.cpp @@ -10,19 +10,6 @@ #include "SkLinearGradient.h" #include "SkRefCnt.h" -static const float kInv255Float = 1.0f / 255; - -static inline int repeat_8bits(int x) { - return x & 0xFF; -} - -static inline int mirror_8bits(int x) { - if (x & 256) { - x = ~x; - } - return x & 255; -} - static SkMatrix pts_to_unit_matrix(const SkPoint pts[2]) { SkVector vec = pts[1] - pts[0]; SkScalar mag = vec.length(); @@ -66,13 +53,7 @@ void SkLinearGradient::flatten(SkWriteBuffer& buffer) const { SkShaderBase::Context* SkLinearGradient::onMakeContext( const ContextRec& rec, SkArenaAlloc* alloc) const { -#ifndef SK_SUPPORT_LEGACY_LINEAR_GRADIENT return CheckedMakeContext(alloc, *this, rec); -#else - return rec.fPreferredDstType == ContextRec::kPM4f_DstType - ? CheckedMakeContext(alloc, *this, rec) - : CheckedMakeContext< LinearGradientContext>(alloc, *this, rec); -#endif } SkShaderBase::Context* SkLinearGradient::onMakeBurstPipelineContext( @@ -96,225 +77,6 @@ sk_sp SkLinearGradient::onMakeColorSpace(SkColorSpaceXformer* xformer) fTileMode, fGradFlags, &this->getLocalMatrix()); } -// This swizzles SkColor into the same component order as SkPMColor, but does not actually -// "pre" multiply the color components. -// -// This allows us to map directly to Sk4f, and eventually scale down to bytes to output a -// SkPMColor from the floats, without having to swizzle each time. -// -static uint32_t SkSwizzle_Color_to_PMColor(SkColor c) { - return SkPackARGB32NoCheck(SkColorGetA(c), SkColorGetR(c), SkColorGetG(c), SkColorGetB(c)); -} - -SkLinearGradient::LinearGradientContext::LinearGradientContext( - const SkLinearGradient& shader, const ContextRec& ctx) - : INHERITED(shader, ctx) -{ - // setup for Sk4f - const int count = shader.fColorCount; - SkASSERT(count > 1); - - fRecs.setCount(count); - Rec* rec = fRecs.begin(); - if (shader.fOrigPos) { - rec[0].fPos = 0; - SkDEBUGCODE(rec[0].fPosScale = SK_FloatNaN;) // should never get used - for (int i = 1; i < count; ++i) { - rec[i].fPos = SkTPin(shader.fOrigPos[i], rec[i - 1].fPos, 1.0f); - float diff = rec[i].fPos - rec[i - 1].fPos; - if (diff > 0) { - rec[i].fPosScale = 1.0f / diff; - } else { - rec[i].fPosScale = 0; - } - } - } else { - // no pos specified, so we compute evenly spaced values - const float scale = float(count - 1); - const float invScale = 1.0f / scale; - for (int i = 0; i < count; ++i) { - rec[i].fPos = i * invScale; - rec[i].fPosScale = scale; - } - } - rec[count - 1].fPos = 1; // overwrite the last value just to be sure we end at 1.0 - - fApplyAlphaAfterInterp = true; - if ((shader.getGradFlags() & SkGradientShader::kInterpolateColorsInPremul_Flag) || - shader.colorsAreOpaque()) - { - fApplyAlphaAfterInterp = false; - } - - if (fApplyAlphaAfterInterp) { - // Our fColor values are in PMColor order, but are still unpremultiplied, allowing us to - // interpolate in unpremultiplied space first, and then scale by alpha right before we - // convert to SkPMColor bytes. - const float paintAlpha = ctx.fPaint->getAlpha() * kInv255Float; - const Sk4f scale(1, 1, 1, paintAlpha); - for (int i = 0; i < count; ++i) { - uint32_t c = SkSwizzle_Color_to_PMColor(shader.fOrigColors[i]); - rec[i].fColor = SkNx_cast(Sk4b::Load(&c)) * scale; - if (i > 0) { - SkASSERT(rec[i - 1].fPos <= rec[i].fPos); - } - } - } else { - // Our fColor values are premultiplied, so converting to SkPMColor is just a matter - // of converting the floats down to bytes. - unsigned alphaScale = ctx.fPaint->getAlpha() + (ctx.fPaint->getAlpha() >> 7); - for (int i = 0; i < count; ++i) { - SkPMColor pmc = SkPreMultiplyColor(shader.fOrigColors[i]); - pmc = SkAlphaMulQ(pmc, alphaScale); - rec[i].fColor = SkNx_cast(Sk4b::Load(&pmc)); - if (i > 0) { - SkASSERT(rec[i - 1].fPos <= rec[i].fPos); - } - } - } -} - -#define NO_CHECK_ITER \ - do { \ - unsigned fi = SkGradFixedToFixed(fx) >> SkGradientShaderBase::kCache32Shift; \ - SkASSERT(fi <= 0xFF); \ - fx += dx; \ - *dstC++ = cache[toggle + fi]; \ - toggle = next_dither_toggle(toggle); \ - } while (0) - -namespace { - -typedef void (*LinearShadeProc)(TileProc proc, SkGradFixed dx, SkGradFixed fx, - SkPMColor* dstC, const SkPMColor* cache, - int toggle, int count); - -// Linear interpolation (lerp) is unnecessary if there are no sharp -// discontinuities in the gradient - which must be true if there are -// only 2 colors - but it's cheap. -void shadeSpan_linear_vertical_lerp(TileProc proc, SkGradFixed dx, SkGradFixed fx, - SkPMColor* SK_RESTRICT dstC, - const SkPMColor* SK_RESTRICT cache, - int toggle, int count) { - // We're a vertical gradient, so no change in a span. - // If colors change sharply across the gradient, dithering is - // insufficient (it subsamples the color space) and we need to lerp. - unsigned fullIndex = proc(SkGradFixedToFixed(fx)); - unsigned fi = fullIndex >> SkGradientShaderBase::kCache32Shift; - unsigned remainder = fullIndex & ((1 << SkGradientShaderBase::kCache32Shift) - 1); - - int index0 = fi + toggle; - int index1 = index0; - if (fi < SkGradientShaderBase::kCache32Count - 1) { - index1 += 1; - } - SkPMColor lerp = SkFastFourByteInterp(cache[index1], cache[index0], remainder); - index0 ^= SkGradientShaderBase::kDitherStride32; - index1 ^= SkGradientShaderBase::kDitherStride32; - SkPMColor dlerp = SkFastFourByteInterp(cache[index1], cache[index0], remainder); - sk_memset32_dither(dstC, lerp, dlerp, count); -} - -void shadeSpan_linear_clamp(TileProc proc, SkGradFixed dx, SkGradFixed fx, - SkPMColor* SK_RESTRICT dstC, - const SkPMColor* SK_RESTRICT cache, - int toggle, int count) { - SkClampRange range; - range.init(fx, dx, count, 0, SkGradientShaderBase::kCache32Count - 1); - range.validate(count); - - if ((count = range.fCount0) > 0) { - sk_memset32_dither(dstC, - cache[toggle + range.fV0], - cache[next_dither_toggle(toggle) + range.fV0], - count); - dstC += count; - } - if ((count = range.fCount1) > 0) { - int unroll = count >> 3; - fx = range.fFx1; - for (int i = 0; i < unroll; i++) { - NO_CHECK_ITER; NO_CHECK_ITER; - NO_CHECK_ITER; NO_CHECK_ITER; - NO_CHECK_ITER; NO_CHECK_ITER; - NO_CHECK_ITER; NO_CHECK_ITER; - } - if ((count &= 7) > 0) { - do { - NO_CHECK_ITER; - } while (--count != 0); - } - } - if ((count = range.fCount2) > 0) { - sk_memset32_dither(dstC, - cache[toggle + range.fV1], - cache[next_dither_toggle(toggle) + range.fV1], - count); - } -} - -void shadeSpan_linear_mirror(TileProc proc, SkGradFixed dx, SkGradFixed fx, - SkPMColor* SK_RESTRICT dstC, - const SkPMColor* SK_RESTRICT cache, - int toggle, int count) { - do { - unsigned fi = mirror_8bits(SkGradFixedToFixed(fx) >> 8); - SkASSERT(fi <= 0xFF); - fx += dx; - *dstC++ = cache[toggle + fi]; - toggle = next_dither_toggle(toggle); - } while (--count != 0); -} - -void shadeSpan_linear_repeat(TileProc proc, SkGradFixed dx, SkGradFixed fx, - SkPMColor* SK_RESTRICT dstC, - const SkPMColor* SK_RESTRICT cache, - int toggle, int count) { - do { - unsigned fi = repeat_8bits(SkGradFixedToFixed(fx) >> 8); - SkASSERT(fi <= 0xFF); - fx += dx; - *dstC++ = cache[toggle + fi]; - toggle = next_dither_toggle(toggle); - } while (--count != 0); -} - -} - -void SkLinearGradient::LinearGradientContext::shadeSpan(int x, int y, SkPMColor* SK_RESTRICT dstC, - int count) { - SkASSERT(count > 0); - const SkLinearGradient& linearGradient = static_cast(fShader); - - if (SkShader::kClamp_TileMode == linearGradient.fTileMode) { - this->shade4_clamp(x, y, dstC, count); - return; - } - - SkPoint srcPt; - SkMatrix::MapXYProc dstProc = fDstToIndexProc; - TileProc proc = linearGradient.fTileProc; - const SkPMColor* SK_RESTRICT cache = fCache->getCache32(); - int toggle = init_dither_toggle(x, y); - - dstProc(fDstToIndex, SkIntToScalar(x) + SK_ScalarHalf, - SkIntToScalar(y) + SK_ScalarHalf, &srcPt); - SkGradFixed fx = SkScalarPinToGradFixed(srcPt.fX), - dx = SkScalarPinToGradFixed(fDstToIndex.getScaleX()); - - LinearShadeProc shadeProc = shadeSpan_linear_repeat; - if (0 == dx) { - shadeProc = shadeSpan_linear_vertical_lerp; - } else if (SkShader::kClamp_TileMode == linearGradient.fTileMode) { - shadeProc = shadeSpan_linear_clamp; - } else if (SkShader::kMirror_TileMode == linearGradient.fTileMode) { - shadeProc = shadeSpan_linear_mirror; - } else { - SkASSERT(SkShader::kRepeat_TileMode == linearGradient.fTileMode); - } - (*shadeProc)(proc, dx, fx, dstC, cache, toggle, count); -} - SkShader::GradientType SkLinearGradient::asAGradient(GradientInfo* info) const { if (info) { commonAsAGradient(info); @@ -479,317 +241,3 @@ void SkLinearGradient::toString(SkString* str) const { str->append(")"); } #endif - -/////////////////////////////////////////////////////////////////////////////////////////////////// - -#include "SkNx.h" - -static const SkLinearGradient::LinearGradientContext::Rec* -find_forward(const SkLinearGradient::LinearGradientContext::Rec rec[], float tiledX) { - SkASSERT(tiledX >= 0 && tiledX <= 1); - - SkASSERT(rec[0].fPos >= 0 && rec[0].fPos <= 1); - SkASSERT(rec[1].fPos >= 0 && rec[1].fPos <= 1); - SkASSERT(rec[0].fPos <= rec[1].fPos); - rec += 1; - while (rec->fPos < tiledX || rec->fPosScale == 0) { - SkASSERT(rec[0].fPos >= 0 && rec[0].fPos <= 1); - SkASSERT(rec[1].fPos >= 0 && rec[1].fPos <= 1); - SkASSERT(rec[0].fPos <= rec[1].fPos); - rec += 1; - } - return rec - 1; -} - -static const SkLinearGradient::LinearGradientContext::Rec* -find_backward(const SkLinearGradient::LinearGradientContext::Rec rec[], float tiledX) { - SkASSERT(tiledX >= 0 && tiledX <= 1); - - SkASSERT(rec[0].fPos >= 0 && rec[0].fPos <= 1); - SkASSERT(rec[1].fPos >= 0 && rec[1].fPos <= 1); - SkASSERT(rec[0].fPos <= rec[1].fPos); - while (tiledX < rec->fPos || rec[1].fPosScale == 0) { - rec -= 1; - SkASSERT(rec[0].fPos >= 0 && rec[0].fPos <= 1); - SkASSERT(rec[1].fPos >= 0 && rec[1].fPos <= 1); - SkASSERT(rec[0].fPos <= rec[1].fPos); - } - return rec; -} - -// As an optimization, we can apply the dither bias before interpolation -- but only when -// operating in premul space (apply_alpha == false). When apply_alpha == true, we must -// defer the bias application until after premul. -// -// The following two helpers encapsulate this logic: pre_bias is called before interpolation, -// and effects the bias when apply_alpha == false, while post_bias is called after premul and -// effects the bias for the apply_alpha == true case. - -template -Sk4f pre_bias(const Sk4f& x, const Sk4f& bias) { - return apply_alpha ? x : x + bias; -} - -template -Sk4f post_bias(const Sk4f& x, const Sk4f& bias) { - return apply_alpha ? x + bias : x; -} - -template SkPMColor trunc_from_255(const Sk4f& x, const Sk4f& bias) { - SkPMColor c; - Sk4f c4f255 = x; - if (apply_alpha) { - // Due to use of multiplication by the 1/255 reciprocal instead of division by 255, - // non-integer alpha values very close to their ceiling can push the color values - // above the alpha value, which will become an invalid premultiplied color. So nudge - // alpha up slightly by a compensating scale to keep it above the color values. - // To do this, multiply alpha by a number slightly greater than 1 to compensate - // for error in scaling from the 1/255 approximation. Since this error is then - // scaled by the alpha value, we need to scale the epsilon by 255 to get a safe - // upper bound on the error. - static constexpr float alphaScale = 1 + 255*std::numeric_limits::epsilon(); - - const float scale = x[SkPM4f::A] * (1 / 255.f); - c4f255 *= Sk4f(scale, scale, scale, alphaScale); - } - SkNx_cast(post_bias(c4f255, bias)).store(&c); - - return c; -} - -template void fill(SkPMColor dst[], int count, - const Sk4f& c4, const Sk4f& bias0, const Sk4f& bias1) { - const SkPMColor c0 = trunc_from_255(pre_bias(c4, bias0), bias0); - const SkPMColor c1 = trunc_from_255(pre_bias(c4, bias1), bias1); - sk_memset32_dither(dst, c0, c1, count); -} - -template void fill(SkPMColor dst[], int count, const Sk4f& c4) { - // Assumes that c4 does not need to be dithered. - sk_memset32(dst, trunc_from_255(c4, 0), count); -} - -/* - * TODOs - * - * - tilemodes - * - interp before or after premul - * - perspective - * - optimizations - * - use fixed (32bit or 16bit) instead of floats? - */ - -static Sk4f lerp_color(float fx, const SkLinearGradient::LinearGradientContext::Rec* rec) { - SkASSERT(fx >= rec[0].fPos); - SkASSERT(fx <= rec[1].fPos); - - const float p0 = rec[0].fPos; - const Sk4f c0 = rec[0].fColor; - const Sk4f c1 = rec[1].fColor; - const Sk4f diffc = c1 - c0; - const float scale = rec[1].fPosScale; - const float t = (fx - p0) * scale; - return c0 + Sk4f(t) * diffc; -} - -template void ramp(SkPMColor dstC[], int n, const Sk4f& c, const Sk4f& dc, - const Sk4f& dither0, const Sk4f& dither1) { - Sk4f dc2 = dc + dc; - Sk4f dc4 = dc2 + dc2; - Sk4f cd0 = pre_bias(c , dither0); - Sk4f cd1 = pre_bias(c + dc, dither1); - Sk4f cd2 = cd0 + dc2; - Sk4f cd3 = cd1 + dc2; - while (n >= 4) { - if (!apply_alpha) { - Sk4f_ToBytes((uint8_t*)dstC, cd0, cd1, cd2, cd3); - dstC += 4; - } else { - *dstC++ = trunc_from_255(cd0, dither0); - *dstC++ = trunc_from_255(cd1, dither1); - *dstC++ = trunc_from_255(cd2, dither0); - *dstC++ = trunc_from_255(cd3, dither1); - } - cd0 = cd0 + dc4; - cd1 = cd1 + dc4; - cd2 = cd2 + dc4; - cd3 = cd3 + dc4; - n -= 4; - } - if (n & 2) { - *dstC++ = trunc_from_255(cd0, dither0); - *dstC++ = trunc_from_255(cd1, dither1); - cd0 = cd0 + dc2; - } - if (n & 1) { - *dstC++ = trunc_from_255(cd0, dither0); - } -} - -static inline uint32_t clamped_advance(float advance) { - SkASSERT(advance >= 0); - return sk_float_floor2int(SkTMin(advance, std::numeric_limits::max() - 1)) + 1; -} - -template -void SkLinearGradient::LinearGradientContext::shade4_dx_clamp(SkPMColor dstC[], int count, - float fx, float dx, float invDx, - const float dither[2]) { - Sk4f dither0(dither[0]); - Sk4f dither1(dither[1]); - const Rec* rec = fRecs.begin(); - - const Sk4f dx4 = Sk4f(dx); - SkDEBUGCODE(SkPMColor* endDstC = dstC + count;) - - if (dx_is_pos) { - if (fx < 0) { - // count is guaranteed to be positive, but the first arg may overflow int32 after - // increment => casting to uint32 ensures correct clamping. - int n = SkTMin(clamped_advance(-fx * invDx), count); - SkASSERT(n > 0); - fill(dstC, n, rec[0].fColor); - count -= n; - dstC += n; - fx += n * dx; - SkASSERT(0 == count || fx >= 0); - if (n & 1) { - SkTSwap(dither0, dither1); - } - } - } else { // dx < 0 - if (fx > 1) { - // count is guaranteed to be positive, but the first arg may overflow int32 after - // increment => casting to uint32 ensures correct clamping. - int n = SkTMin(clamped_advance((1 - fx) * invDx), count); - SkASSERT(n > 0); - fill(dstC, n, rec[fRecs.count() - 1].fColor); - count -= n; - dstC += n; - fx += n * dx; - SkASSERT(0 == count || fx <= 1); - if (n & 1) { - SkTSwap(dither0, dither1); - } - } - } - SkASSERT(count >= 0); - - const Rec* r; - if (dx_is_pos) { - r = fRecs.begin(); // start at the beginning - } else { - r = fRecs.begin() + fRecs.count() - 2; // start at the end - } - - while (count > 0) { - if (dx_is_pos) { - if (fx >= 1) { - fill(dstC, count, rec[fRecs.count() - 1].fColor); - return; - } - } else { // dx < 0 - if (fx <= 0) { - fill(dstC, count, rec[0].fColor); - return; - } - } - - if (dx_is_pos) { - r = find_forward(r, fx); - } else { - r = find_backward(r, fx); - } - SkASSERT(r >= fRecs.begin() && r < fRecs.begin() + fRecs.count() - 1); - - const float p0 = r[0].fPos; - const Sk4f c0 = r[0].fColor; - const float p1 = r[1].fPos; - const Sk4f diffc = Sk4f(r[1].fColor) - c0; - const float scale = r[1].fPosScale; - const float t = (fx - p0) * scale; - const Sk4f c = c0 + Sk4f(t) * diffc; - const Sk4f dc = diffc * dx4 * Sk4f(scale); - - int n; - if (dx_is_pos) { - n = SkTMin((int)((p1 - fx) * invDx) + 1, count); - } else { - n = SkTMin((int)((p0 - fx) * invDx) + 1, count); - } - - fx += n * dx; - // fx should now outside of the p0..p1 interval. However, due to float precision loss, - // its possible that fx is slightly too small/large, so we clamp it. - if (dx_is_pos) { - fx = SkTMax(fx, p1); - } else { - fx = SkTMin(fx, p0); - } - - ramp(dstC, n, c, dc, dither0, dither1); - dstC += n; - SkASSERT(dstC <= endDstC); - - if (n & 1) { - SkTSwap(dither0, dither1); - } - - count -= n; - SkASSERT(count >= 0); - } -} - -void SkLinearGradient::LinearGradientContext::shade4_clamp(int x, int y, SkPMColor dstC[], - int count) { - SkASSERT(count > 0); - - SkPoint srcPt; - fDstToIndexProc(fDstToIndex, x + SK_ScalarHalf, y + SK_ScalarHalf, &srcPt); - float fx = srcPt.x(); - const float dx = fDstToIndex.getScaleX(); - - // Default our dither bias values to 1/2, (rounding), which is no dithering - float dither0 = 0.5f; - float dither1 = 0.5f; - if (fDither) { - const float ditherCell[] = { - 1/8.0f, 5/8.0f, - 7/8.0f, 3/8.0f, - }; - const int rowIndex = (y & 1) << 1; - dither0 = ditherCell[rowIndex]; - dither1 = ditherCell[rowIndex + 1]; - if (x & 1) { - SkTSwap(dither0, dither1); - } - } - const float dither[2] = { dither0, dither1 }; - - if (SkScalarNearlyZero(dx * count)) { // gradient is vertical - const float pinFx = SkTPin(fx, 0.0f, 1.0f); - Sk4f c = lerp_color(pinFx, find_forward(fRecs.begin(), pinFx)); - if (fApplyAlphaAfterInterp) { - fill(dstC, count, c, dither0, dither1); - } else { - fill(dstC, count, c, dither0, dither1); - } - return; - } - - SkASSERT(0.f != dx); - const float invDx = 1 / dx; - if (dx > 0) { - if (fApplyAlphaAfterInterp) { - this->shade4_dx_clamp(dstC, count, fx, dx, invDx, dither); - } else { - this->shade4_dx_clamp(dstC, count, fx, dx, invDx, dither); - } - } else { - if (fApplyAlphaAfterInterp) { - this->shade4_dx_clamp(dstC, count, fx, dx, invDx, dither); - } else { - this->shade4_dx_clamp(dstC, count, fx, dx, invDx, dither); - } - } -} diff --git a/src/shaders/gradients/SkLinearGradient.h b/src/shaders/gradients/SkLinearGradient.h index 64db9dcdb3..c93f2b4ed3 100644 --- a/src/shaders/gradients/SkLinearGradient.h +++ b/src/shaders/gradients/SkLinearGradient.h @@ -9,47 +9,11 @@ #define SkLinearGradient_DEFINED #include "SkGradientShaderPriv.h" -#include "SkNx.h" - -struct Sk4fStorage { - float fArray[4]; - - operator Sk4f() const { - return Sk4f::Load(fArray); - } - - Sk4fStorage& operator=(const Sk4f& src) { - src.store(fArray); - return *this; - } -}; class SkLinearGradient : public SkGradientShaderBase { public: SkLinearGradient(const SkPoint pts[2], const Descriptor&); - class LinearGradientContext : public SkGradientShaderBase::GradientShaderBaseContext { - public: - LinearGradientContext(const SkLinearGradient&, const ContextRec&); - - void shadeSpan(int x, int y, SkPMColor dstC[], int count) override; - - struct Rec { - Sk4fStorage fColor; - float fPos; - float fPosScale; - }; - private: - SkTDArray fRecs; - bool fApplyAlphaAfterInterp; - - void shade4_clamp(int x, int y, SkPMColor dstC[], int count); - template void shade4_dx_clamp(SkPMColor dstC[], int count, float fx, float dx, - float invDx, const float dither[2]); - - typedef SkGradientShaderBase::GradientShaderBaseContext INHERITED; - }; - GradientType asAGradient(GradientInfo* info) const override; #if SK_SUPPORT_GPU std::unique_ptr asFragmentProcessor(const AsFPArgs&) const override; -- cgit v1.2.3