| /* |
| * Copyright 2017 Google Inc. |
| * |
| * Use of this source code is governed by a BSD-style license that can be |
| * found in the LICENSE file. |
| */ |
| |
| #include "src/pdf/SkPDFGradientShader.h" |
| |
| #include "include/docs/SkPDFDocument.h" |
| #include "src/core/SkOpts.h" |
| #include "src/pdf/SkPDFDocumentPriv.h" |
| #include "src/pdf/SkPDFFormXObject.h" |
| #include "src/pdf/SkPDFGraphicState.h" |
| #include "src/pdf/SkPDFResourceDict.h" |
| #include "src/pdf/SkPDFTypes.h" |
| #include "src/pdf/SkPDFUtils.h" |
| |
| static uint32_t hash(const SkShader::GradientInfo& v) { |
| uint32_t buffer[] = { |
| (uint32_t)v.fColorCount, |
| SkOpts::hash(v.fColors, v.fColorCount * sizeof(SkColor)), |
| SkOpts::hash(v.fColorOffsets, v.fColorCount * sizeof(SkScalar)), |
| SkOpts::hash(v.fPoint, 2 * sizeof(SkPoint)), |
| SkOpts::hash(v.fRadius, 2 * sizeof(SkScalar)), |
| (uint32_t)v.fTileMode, |
| v.fGradientFlags, |
| }; |
| return SkOpts::hash(buffer, sizeof(buffer)); |
| } |
| |
| static uint32_t hash(const SkPDFGradientShader::Key& k) { |
| uint32_t buffer[] = { |
| (uint32_t)k.fType, |
| hash(k.fInfo), |
| SkOpts::hash(&k.fCanvasTransform, sizeof(SkMatrix)), |
| SkOpts::hash(&k.fShaderTransform, sizeof(SkMatrix)), |
| SkOpts::hash(&k.fBBox, sizeof(SkIRect)) |
| }; |
| return SkOpts::hash(buffer, sizeof(buffer)); |
| } |
| |
| static void unit_to_points_matrix(const SkPoint pts[2], SkMatrix* matrix) { |
| SkVector vec = pts[1] - pts[0]; |
| SkScalar mag = vec.length(); |
| SkScalar inv = mag ? SkScalarInvert(mag) : 0; |
| |
| vec.scale(inv); |
| matrix->setSinCos(vec.fY, vec.fX); |
| matrix->preScale(mag, mag); |
| matrix->postTranslate(pts[0].fX, pts[0].fY); |
| } |
| |
| static const int kColorComponents = 3; |
| typedef uint8_t ColorTuple[kColorComponents]; |
| |
| /* Assumes t + startOffset is on the stack and does a linear interpolation on t |
| between startOffset and endOffset from prevColor to curColor (for each color |
| component), leaving the result in component order on the stack. It assumes |
| there are always 3 components per color. |
| @param range endOffset - startOffset |
| @param curColor[components] The current color components. |
| @param prevColor[components] The previous color components. |
| @param result The result ps function. |
| */ |
| static void interpolate_color_code(SkScalar range, const ColorTuple& curColor, |
| const ColorTuple& prevColor, |
| SkDynamicMemoryWStream* result) { |
| SkASSERT(range != SkIntToScalar(0)); |
| |
| // Figure out how to scale each color component. |
| SkScalar multiplier[kColorComponents]; |
| for (int i = 0; i < kColorComponents; i++) { |
| static const SkScalar kColorScale = SkScalarInvert(255); |
| multiplier[i] = kColorScale * (curColor[i] - prevColor[i]) / range; |
| } |
| |
| // Calculate when we no longer need to keep a copy of the input parameter t. |
| // If the last component to use t is i, then dupInput[0..i - 1] = true |
| // and dupInput[i .. components] = false. |
| bool dupInput[kColorComponents]; |
| dupInput[kColorComponents - 1] = false; |
| for (int i = kColorComponents - 2; i >= 0; i--) { |
| dupInput[i] = dupInput[i + 1] || multiplier[i + 1] != 0; |
| } |
| |
| if (!dupInput[0] && multiplier[0] == 0) { |
| result->writeText("pop "); |
| } |
| |
| for (int i = 0; i < kColorComponents; i++) { |
| // If the next components needs t and this component will consume a |
| // copy, make another copy. |
| if (dupInput[i] && multiplier[i] != 0) { |
| result->writeText("dup "); |
| } |
| |
| if (multiplier[i] == 0) { |
| SkPDFUtils::AppendColorComponent(prevColor[i], result); |
| result->writeText(" "); |
| } else { |
| if (multiplier[i] != 1) { |
| SkPDFUtils::AppendScalar(multiplier[i], result); |
| result->writeText(" mul "); |
| } |
| if (prevColor[i] != 0) { |
| SkPDFUtils::AppendColorComponent(prevColor[i], result); |
| result->writeText(" add "); |
| } |
| } |
| |
| if (dupInput[i]) { |
| result->writeText("exch\n"); |
| } |
| } |
| } |
| |
| /* Generate Type 4 function code to map t=[0,1) to the passed gradient, |
| clamping at the edges of the range. The generated code will be of the form: |
| if (t < 0) { |
| return colorData[0][r,g,b]; |
| } else { |
| if (t < info.fColorOffsets[1]) { |
| return linearinterpolation(colorData[0][r,g,b], |
| colorData[1][r,g,b]); |
| } else { |
| if (t < info.fColorOffsets[2]) { |
| return linearinterpolation(colorData[1][r,g,b], |
| colorData[2][r,g,b]); |
| } else { |
| |
| ... } else { |
| return colorData[info.fColorCount - 1][r,g,b]; |
| } |
| ... |
| } |
| } |
| */ |
| static void gradient_function_code(const SkShader::GradientInfo& info, |
| SkDynamicMemoryWStream* result) { |
| /* We want to linearly interpolate from the previous color to the next. |
| Scale the colors from 0..255 to 0..1 and determine the multipliers |
| for interpolation. |
| C{r,g,b}(t, section) = t - offset_(section-1) + t * Multiplier{r,g,b}. |
| */ |
| |
| SkAutoSTMalloc<4, ColorTuple> colorDataAlloc(info.fColorCount); |
| ColorTuple *colorData = colorDataAlloc.get(); |
| for (int i = 0; i < info.fColorCount; i++) { |
| colorData[i][0] = SkColorGetR(info.fColors[i]); |
| colorData[i][1] = SkColorGetG(info.fColors[i]); |
| colorData[i][2] = SkColorGetB(info.fColors[i]); |
| } |
| |
| // Clamp the initial color. |
| result->writeText("dup 0 le {pop "); |
| SkPDFUtils::AppendColorComponent(colorData[0][0], result); |
| result->writeText(" "); |
| SkPDFUtils::AppendColorComponent(colorData[0][1], result); |
| result->writeText(" "); |
| SkPDFUtils::AppendColorComponent(colorData[0][2], result); |
| result->writeText(" }\n"); |
| |
| // The gradient colors. |
| int gradients = 0; |
| for (int i = 1 ; i < info.fColorCount; i++) { |
| if (info.fColorOffsets[i] == info.fColorOffsets[i - 1]) { |
| continue; |
| } |
| gradients++; |
| |
| result->writeText("{dup "); |
| SkPDFUtils::AppendScalar(info.fColorOffsets[i], result); |
| result->writeText(" le {"); |
| if (info.fColorOffsets[i - 1] != 0) { |
| SkPDFUtils::AppendScalar(info.fColorOffsets[i - 1], result); |
| result->writeText(" sub\n"); |
| } |
| |
| interpolate_color_code(info.fColorOffsets[i] - info.fColorOffsets[i - 1], |
| colorData[i], colorData[i - 1], result); |
| result->writeText("}\n"); |
| } |
| |
| // Clamp the final color. |
| result->writeText("{pop "); |
| SkPDFUtils::AppendColorComponent(colorData[info.fColorCount - 1][0], result); |
| result->writeText(" "); |
| SkPDFUtils::AppendColorComponent(colorData[info.fColorCount - 1][1], result); |
| result->writeText(" "); |
| SkPDFUtils::AppendColorComponent(colorData[info.fColorCount - 1][2], result); |
| |
| for (int i = 0 ; i < gradients + 1; i++) { |
| result->writeText("} ifelse\n"); |
| } |
| } |
| |
| static std::unique_ptr<SkPDFDict> createInterpolationFunction(const ColorTuple& color1, |
| const ColorTuple& color2) { |
| auto retval = SkPDFMakeDict(); |
| |
| auto c0 = SkPDFMakeArray(); |
| c0->appendColorComponent(color1[0]); |
| c0->appendColorComponent(color1[1]); |
| c0->appendColorComponent(color1[2]); |
| retval->insertObject("C0", std::move(c0)); |
| |
| auto c1 = SkPDFMakeArray(); |
| c1->appendColorComponent(color2[0]); |
| c1->appendColorComponent(color2[1]); |
| c1->appendColorComponent(color2[2]); |
| retval->insertObject("C1", std::move(c1)); |
| |
| retval->insertObject("Domain", SkPDFMakeArray(0, 1)); |
| |
| retval->insertInt("FunctionType", 2); |
| retval->insertScalar("N", 1.0f); |
| |
| return retval; |
| } |
| |
| static std::unique_ptr<SkPDFDict> gradientStitchCode(const SkShader::GradientInfo& info) { |
| auto retval = SkPDFMakeDict(); |
| |
| // normalize color stops |
| int colorCount = info.fColorCount; |
| std::vector<SkColor> colors(info.fColors, info.fColors + colorCount); |
| std::vector<SkScalar> colorOffsets(info.fColorOffsets, info.fColorOffsets + colorCount); |
| |
| int i = 1; |
| while (i < colorCount - 1) { |
| // ensure stops are in order |
| if (colorOffsets[i - 1] > colorOffsets[i]) { |
| colorOffsets[i] = colorOffsets[i - 1]; |
| } |
| |
| // remove points that are between 2 coincident points |
| if ((colorOffsets[i - 1] == colorOffsets[i]) && (colorOffsets[i] == colorOffsets[i + 1])) { |
| colorCount -= 1; |
| colors.erase(colors.begin() + i); |
| colorOffsets.erase(colorOffsets.begin() + i); |
| } else { |
| i++; |
| } |
| } |
| // find coincident points and slightly move them over |
| for (i = 1; i < colorCount - 1; i++) { |
| if (colorOffsets[i - 1] == colorOffsets[i]) { |
| colorOffsets[i] += 0.00001f; |
| } |
| } |
| // check if last 2 stops coincide |
| if (colorOffsets[i - 1] == colorOffsets[i]) { |
| colorOffsets[i - 1] -= 0.00001f; |
| } |
| |
| SkAutoSTMalloc<4, ColorTuple> colorDataAlloc(colorCount); |
| ColorTuple *colorData = colorDataAlloc.get(); |
| for (int i = 0; i < colorCount; i++) { |
| colorData[i][0] = SkColorGetR(colors[i]); |
| colorData[i][1] = SkColorGetG(colors[i]); |
| colorData[i][2] = SkColorGetB(colors[i]); |
| } |
| |
| // no need for a stitch function if there are only 2 stops. |
| if (colorCount == 2) |
| return createInterpolationFunction(colorData[0], colorData[1]); |
| |
| auto encode = SkPDFMakeArray(); |
| auto bounds = SkPDFMakeArray(); |
| auto functions = SkPDFMakeArray(); |
| |
| retval->insertObject("Domain", SkPDFMakeArray(0, 1)); |
| retval->insertInt("FunctionType", 3); |
| |
| for (int i = 1; i < colorCount; i++) { |
| if (i > 1) { |
| bounds->appendScalar(colorOffsets[i-1]); |
| } |
| |
| encode->appendScalar(0); |
| encode->appendScalar(1.0f); |
| |
| functions->appendObject(createInterpolationFunction(colorData[i-1], colorData[i])); |
| } |
| |
| retval->insertObject("Encode", std::move(encode)); |
| retval->insertObject("Bounds", std::move(bounds)); |
| retval->insertObject("Functions", std::move(functions)); |
| |
| return retval; |
| } |
| |
| /* Map a value of t on the stack into [0, 1) for Repeat or Mirror tile mode. */ |
| static void tileModeCode(SkTileMode mode, SkDynamicMemoryWStream* result) { |
| if (mode == SkTileMode::kRepeat) { |
| result->writeText("dup truncate sub\n"); // Get the fractional part. |
| result->writeText("dup 0 le {1 add} if\n"); // Map (-1,0) => (0,1) |
| return; |
| } |
| |
| if (mode == SkTileMode::kMirror) { |
| // Map t mod 2 into [0, 1, 1, 0]. |
| // Code Stack |
| result->writeText("abs " // Map negative to positive. |
| "dup " // t.s t.s |
| "truncate " // t.s t |
| "dup " // t.s t t |
| "cvi " // t.s t T |
| "2 mod " // t.s t (i mod 2) |
| "1 eq " // t.s t true|false |
| "3 1 roll " // true|false t.s t |
| "sub " // true|false 0.s |
| "exch " // 0.s true|false |
| "{1 exch sub} if\n"); // 1 - 0.s|0.s |
| } |
| } |
| |
| /** |
| * Returns PS function code that applies inverse perspective |
| * to a x, y point. |
| * The function assumes that the stack has at least two elements, |
| * and that the top 2 elements are numeric values. |
| * After executing this code on a PS stack, the last 2 elements are updated |
| * while the rest of the stack is preserved intact. |
| * inversePerspectiveMatrix is the inverse perspective matrix. |
| */ |
| static void apply_perspective_to_coordinates(const SkMatrix& inversePerspectiveMatrix, |
| SkDynamicMemoryWStream* code) { |
| if (!inversePerspectiveMatrix.hasPerspective()) { |
| return; |
| } |
| |
| // Perspective matrix should be: |
| // 1 0 0 |
| // 0 1 0 |
| // p0 p1 p2 |
| |
| const SkScalar p0 = inversePerspectiveMatrix[SkMatrix::kMPersp0]; |
| const SkScalar p1 = inversePerspectiveMatrix[SkMatrix::kMPersp1]; |
| const SkScalar p2 = inversePerspectiveMatrix[SkMatrix::kMPersp2]; |
| |
| // y = y / (p2 + p0 x + p1 y) |
| // x = x / (p2 + p0 x + p1 y) |
| |
| // Input on stack: x y |
| code->writeText(" dup "); // x y y |
| SkPDFUtils::AppendScalar(p1, code); // x y y p1 |
| code->writeText(" mul " // x y y*p1 |
| " 2 index "); // x y y*p1 x |
| SkPDFUtils::AppendScalar(p0, code); // x y y p1 x p0 |
| code->writeText(" mul "); // x y y*p1 x*p0 |
| SkPDFUtils::AppendScalar(p2, code); // x y y p1 x*p0 p2 |
| code->writeText(" add " // x y y*p1 x*p0+p2 |
| "add " // x y y*p1+x*p0+p2 |
| "3 1 roll " // y*p1+x*p0+p2 x y |
| "2 index " // z x y y*p1+x*p0+p2 |
| "div " // y*p1+x*p0+p2 x y/(y*p1+x*p0+p2) |
| "3 1 roll " // y/(y*p1+x*p0+p2) y*p1+x*p0+p2 x |
| "exch " // y/(y*p1+x*p0+p2) x y*p1+x*p0+p2 |
| "div " // y/(y*p1+x*p0+p2) x/(y*p1+x*p0+p2) |
| "exch\n"); // x/(y*p1+x*p0+p2) y/(y*p1+x*p0+p2) |
| } |
| |
| static void linearCode(const SkShader::GradientInfo& info, |
| const SkMatrix& perspectiveRemover, |
| SkDynamicMemoryWStream* function) { |
| function->writeText("{"); |
| |
| apply_perspective_to_coordinates(perspectiveRemover, function); |
| |
| function->writeText("pop\n"); // Just ditch the y value. |
| tileModeCode((SkTileMode)info.fTileMode, function); |
| gradient_function_code(info, function); |
| function->writeText("}"); |
| } |
| |
| static void radialCode(const SkShader::GradientInfo& info, |
| const SkMatrix& perspectiveRemover, |
| SkDynamicMemoryWStream* function) { |
| function->writeText("{"); |
| |
| apply_perspective_to_coordinates(perspectiveRemover, function); |
| |
| // Find the distance from the origin. |
| function->writeText("dup " // x y y |
| "mul " // x y^2 |
| "exch " // y^2 x |
| "dup " // y^2 x x |
| "mul " // y^2 x^2 |
| "add " // y^2+x^2 |
| "sqrt\n"); // sqrt(y^2+x^2) |
| |
| tileModeCode((SkTileMode)info.fTileMode, function); |
| gradient_function_code(info, function); |
| function->writeText("}"); |
| } |
| |
| /* Conical gradient shader, based on the Canvas spec for radial gradients |
| See: http://www.w3.org/TR/2dcontext/#dom-context-2d-createradialgradient |
| */ |
| static void twoPointConicalCode(const SkShader::GradientInfo& info, |
| const SkMatrix& perspectiveRemover, |
| SkDynamicMemoryWStream* function) { |
| SkScalar dx = info.fPoint[1].fX - info.fPoint[0].fX; |
| SkScalar dy = info.fPoint[1].fY - info.fPoint[0].fY; |
| SkScalar r0 = info.fRadius[0]; |
| SkScalar dr = info.fRadius[1] - info.fRadius[0]; |
| SkScalar a = dx * dx + dy * dy - dr * dr; |
| |
| // First compute t, if the pixel falls outside the cone, then we'll end |
| // with 'false' on the stack, otherwise we'll push 'true' with t below it |
| |
| // We start with a stack of (x y), copy it and then consume one copy in |
| // order to calculate b and the other to calculate c. |
| function->writeText("{"); |
| |
| apply_perspective_to_coordinates(perspectiveRemover, function); |
| |
| function->writeText("2 copy "); |
| |
| // Calculate b and b^2; b = -2 * (y * dy + x * dx + r0 * dr). |
| SkPDFUtils::AppendScalar(dy, function); |
| function->writeText(" mul exch "); |
| SkPDFUtils::AppendScalar(dx, function); |
| function->writeText(" mul add "); |
| SkPDFUtils::AppendScalar(r0 * dr, function); |
| function->writeText(" add -2 mul dup dup mul\n"); |
| |
| // c = x^2 + y^2 + radius0^2 |
| function->writeText("4 2 roll dup mul exch dup mul add "); |
| SkPDFUtils::AppendScalar(r0 * r0, function); |
| function->writeText(" sub dup 4 1 roll\n"); |
| |
| // Contents of the stack at this point: c, b, b^2, c |
| |
| // if a = 0, then we collapse to a simpler linear case |
| if (a == 0) { |
| |
| // t = -c/b |
| function->writeText("pop pop div neg dup "); |
| |
| // compute radius(t) |
| SkPDFUtils::AppendScalar(dr, function); |
| function->writeText(" mul "); |
| SkPDFUtils::AppendScalar(r0, function); |
| function->writeText(" add\n"); |
| |
| // if r(t) < 0, then it's outside the cone |
| function->writeText("0 lt {pop false} {true} ifelse\n"); |
| |
| } else { |
| |
| // quadratic case: the Canvas spec wants the largest |
| // root t for which radius(t) > 0 |
| |
| // compute the discriminant (b^2 - 4ac) |
| SkPDFUtils::AppendScalar(a * 4, function); |
| function->writeText(" mul sub dup\n"); |
| |
| // if d >= 0, proceed |
| function->writeText("0 ge {\n"); |
| |
| // an intermediate value we'll use to compute the roots: |
| // q = -0.5 * (b +/- sqrt(d)) |
| function->writeText("sqrt exch dup 0 lt {exch -1 mul} if"); |
| function->writeText(" add -0.5 mul dup\n"); |
| |
| // first root = q / a |
| SkPDFUtils::AppendScalar(a, function); |
| function->writeText(" div\n"); |
| |
| // second root = c / q |
| function->writeText("3 1 roll div\n"); |
| |
| // put the larger root on top of the stack |
| function->writeText("2 copy gt {exch} if\n"); |
| |
| // compute radius(t) for larger root |
| function->writeText("dup "); |
| SkPDFUtils::AppendScalar(dr, function); |
| function->writeText(" mul "); |
| SkPDFUtils::AppendScalar(r0, function); |
| function->writeText(" add\n"); |
| |
| // if r(t) > 0, we have our t, pop off the smaller root and we're done |
| function->writeText(" 0 gt {exch pop true}\n"); |
| |
| // otherwise, throw out the larger one and try the smaller root |
| function->writeText("{pop dup\n"); |
| SkPDFUtils::AppendScalar(dr, function); |
| function->writeText(" mul "); |
| SkPDFUtils::AppendScalar(r0, function); |
| function->writeText(" add\n"); |
| |
| // if r(t) < 0, push false, otherwise the smaller root is our t |
| function->writeText("0 le {pop false} {true} ifelse\n"); |
| function->writeText("} ifelse\n"); |
| |
| // d < 0, clear the stack and push false |
| function->writeText("} {pop pop pop false} ifelse\n"); |
| } |
| |
| // if the pixel is in the cone, proceed to compute a color |
| function->writeText("{"); |
| tileModeCode((SkTileMode)info.fTileMode, function); |
| gradient_function_code(info, function); |
| |
| // otherwise, just write black |
| function->writeText("} {0 0 0} ifelse }"); |
| } |
| |
| static void sweepCode(const SkShader::GradientInfo& info, |
| const SkMatrix& perspectiveRemover, |
| SkDynamicMemoryWStream* function) { |
| function->writeText("{exch atan 360 div\n"); |
| tileModeCode((SkTileMode)info.fTileMode, function); |
| gradient_function_code(info, function); |
| function->writeText("}"); |
| } |
| |
| |
| // catch cases where the inner just touches the outer circle |
| // and make the inner circle just inside the outer one to match raster |
| static void FixUpRadius(const SkPoint& p1, SkScalar& r1, const SkPoint& p2, SkScalar& r2) { |
| // detect touching circles |
| SkScalar distance = SkPoint::Distance(p1, p2); |
| SkScalar subtractRadii = fabs(r1 - r2); |
| if (fabs(distance - subtractRadii) < 0.002f) { |
| if (r1 > r2) { |
| r1 += 0.002f; |
| } else { |
| r2 += 0.002f; |
| } |
| } |
| } |
| |
| // Finds affine and persp such that in = affine * persp. |
| // but it returns the inverse of perspective matrix. |
| static bool split_perspective(const SkMatrix in, SkMatrix* affine, |
| SkMatrix* perspectiveInverse) { |
| const SkScalar p2 = in[SkMatrix::kMPersp2]; |
| |
| if (SkScalarNearlyZero(p2)) { |
| return false; |
| } |
| |
| const SkScalar zero = SkIntToScalar(0); |
| const SkScalar one = SkIntToScalar(1); |
| |
| const SkScalar sx = in[SkMatrix::kMScaleX]; |
| const SkScalar kx = in[SkMatrix::kMSkewX]; |
| const SkScalar tx = in[SkMatrix::kMTransX]; |
| const SkScalar ky = in[SkMatrix::kMSkewY]; |
| const SkScalar sy = in[SkMatrix::kMScaleY]; |
| const SkScalar ty = in[SkMatrix::kMTransY]; |
| const SkScalar p0 = in[SkMatrix::kMPersp0]; |
| const SkScalar p1 = in[SkMatrix::kMPersp1]; |
| |
| // Perspective matrix would be: |
| // 1 0 0 |
| // 0 1 0 |
| // p0 p1 p2 |
| // But we need the inverse of persp. |
| perspectiveInverse->setAll(one, zero, zero, |
| zero, one, zero, |
| -p0/p2, -p1/p2, 1/p2); |
| |
| affine->setAll(sx - p0 * tx / p2, kx - p1 * tx / p2, tx / p2, |
| ky - p0 * ty / p2, sy - p1 * ty / p2, ty / p2, |
| zero, zero, one); |
| |
| return true; |
| } |
| |
| static SkPDFIndirectReference make_ps_function(std::unique_ptr<SkStreamAsset> psCode, |
| std::unique_ptr<SkPDFArray> domain, |
| std::unique_ptr<SkPDFObject> range, |
| SkPDFDocument* doc) { |
| std::unique_ptr<SkPDFDict> dict = SkPDFMakeDict(); |
| dict->insertInt("FunctionType", 4); |
| dict->insertObject("Domain", std::move(domain)); |
| dict->insertObject("Range", std::move(range)); |
| return SkPDFStreamOut(std::move(dict), std::move(psCode), doc); |
| } |
| |
| static SkPDFIndirectReference make_function_shader(SkPDFDocument* doc, |
| const SkPDFGradientShader::Key& state) { |
| SkPoint transformPoints[2]; |
| const SkShader::GradientInfo& info = state.fInfo; |
| SkMatrix finalMatrix = state.fCanvasTransform; |
| finalMatrix.preConcat(state.fShaderTransform); |
| |
| bool doStitchFunctions = (state.fType == SkShader::kLinear_GradientType || |
| state.fType == SkShader::kRadial_GradientType || |
| state.fType == SkShader::kConical_GradientType) && |
| (SkTileMode)info.fTileMode == SkTileMode::kClamp && |
| !finalMatrix.hasPerspective(); |
| |
| int32_t shadingType = 1; |
| auto pdfShader = SkPDFMakeDict(); |
| // The two point radial gradient further references |
| // state.fInfo |
| // in translating from x, y coordinates to the t parameter. So, we have |
| // to transform the points and radii according to the calculated matrix. |
| if (doStitchFunctions) { |
| pdfShader->insertObject("Function", gradientStitchCode(info)); |
| shadingType = (state.fType == SkShader::kLinear_GradientType) ? 2 : 3; |
| |
| auto extend = SkPDFMakeArray(); |
| extend->reserve(2); |
| extend->appendBool(true); |
| extend->appendBool(true); |
| pdfShader->insertObject("Extend", std::move(extend)); |
| |
| std::unique_ptr<SkPDFArray> coords; |
| if (state.fType == SkShader::kConical_GradientType) { |
| SkScalar r1 = info.fRadius[0]; |
| SkScalar r2 = info.fRadius[1]; |
| SkPoint pt1 = info.fPoint[0]; |
| SkPoint pt2 = info.fPoint[1]; |
| FixUpRadius(pt1, r1, pt2, r2); |
| |
| coords = SkPDFMakeArray(pt1.x(), |
| pt1.y(), |
| r1, |
| pt2.x(), |
| pt2.y(), |
| r2); |
| } else if (state.fType == SkShader::kRadial_GradientType) { |
| const SkPoint& pt1 = info.fPoint[0]; |
| coords = SkPDFMakeArray(pt1.x(), |
| pt1.y(), |
| 0, |
| pt1.x(), |
| pt1.y(), |
| info.fRadius[0]); |
| } else { |
| const SkPoint& pt1 = info.fPoint[0]; |
| const SkPoint& pt2 = info.fPoint[1]; |
| coords = SkPDFMakeArray(pt1.x(), |
| pt1.y(), |
| pt2.x(), |
| pt2.y()); |
| } |
| |
| pdfShader->insertObject("Coords", std::move(coords)); |
| } else { |
| // Depending on the type of the gradient, we want to transform the |
| // coordinate space in different ways. |
| transformPoints[0] = info.fPoint[0]; |
| transformPoints[1] = info.fPoint[1]; |
| switch (state.fType) { |
| case SkShader::kLinear_GradientType: |
| break; |
| case SkShader::kRadial_GradientType: |
| transformPoints[1] = transformPoints[0]; |
| transformPoints[1].fX += info.fRadius[0]; |
| break; |
| case SkShader::kConical_GradientType: { |
| transformPoints[1] = transformPoints[0]; |
| transformPoints[1].fX += SK_Scalar1; |
| break; |
| } |
| case SkShader::kSweep_GradientType: |
| transformPoints[1] = transformPoints[0]; |
| transformPoints[1].fX += SK_Scalar1; |
| break; |
| case SkShader::kColor_GradientType: |
| case SkShader::kNone_GradientType: |
| default: |
| return SkPDFIndirectReference(); |
| } |
| |
| // Move any scaling (assuming a unit gradient) or translation |
| // (and rotation for linear gradient), of the final gradient from |
| // info.fPoints to the matrix (updating bbox appropriately). Now |
| // the gradient can be drawn on on the unit segment. |
| SkMatrix mapperMatrix; |
| unit_to_points_matrix(transformPoints, &mapperMatrix); |
| |
| finalMatrix.preConcat(mapperMatrix); |
| |
| // Preserves as much as possible in the final matrix, and only removes |
| // the perspective. The inverse of the perspective is stored in |
| // perspectiveInverseOnly matrix and has 3 useful numbers |
| // (p0, p1, p2), while everything else is either 0 or 1. |
| // In this way the shader will handle it eficiently, with minimal code. |
| SkMatrix perspectiveInverseOnly = SkMatrix::I(); |
| if (finalMatrix.hasPerspective()) { |
| if (!split_perspective(finalMatrix, |
| &finalMatrix, &perspectiveInverseOnly)) { |
| return SkPDFIndirectReference(); |
| } |
| } |
| |
| SkRect bbox; |
| bbox.set(state.fBBox); |
| if (!SkPDFUtils::InverseTransformBBox(finalMatrix, &bbox)) { |
| return SkPDFIndirectReference(); |
| } |
| SkDynamicMemoryWStream functionCode; |
| |
| SkShader::GradientInfo infoCopy = info; |
| |
| if (state.fType == SkShader::kConical_GradientType) { |
| SkMatrix inverseMapperMatrix; |
| if (!mapperMatrix.invert(&inverseMapperMatrix)) { |
| return SkPDFIndirectReference(); |
| } |
| inverseMapperMatrix.mapPoints(infoCopy.fPoint, 2); |
| infoCopy.fRadius[0] = inverseMapperMatrix.mapRadius(info.fRadius[0]); |
| infoCopy.fRadius[1] = inverseMapperMatrix.mapRadius(info.fRadius[1]); |
| } |
| switch (state.fType) { |
| case SkShader::kLinear_GradientType: |
| linearCode(infoCopy, perspectiveInverseOnly, &functionCode); |
| break; |
| case SkShader::kRadial_GradientType: |
| radialCode(infoCopy, perspectiveInverseOnly, &functionCode); |
| break; |
| case SkShader::kConical_GradientType: |
| twoPointConicalCode(infoCopy, perspectiveInverseOnly, &functionCode); |
| break; |
| case SkShader::kSweep_GradientType: |
| sweepCode(infoCopy, perspectiveInverseOnly, &functionCode); |
| break; |
| default: |
| SkASSERT(false); |
| } |
| pdfShader->insertObject( |
| "Domain", SkPDFMakeArray(bbox.left(), bbox.right(), bbox.top(), bbox.bottom())); |
| |
| auto domain = SkPDFMakeArray(bbox.left(), bbox.right(), bbox.top(), bbox.bottom()); |
| std::unique_ptr<SkPDFArray> rangeObject = SkPDFMakeArray(0, 1, 0, 1, 0, 1); |
| pdfShader->insertRef("Function", |
| make_ps_function(functionCode.detachAsStream(), std::move(domain), |
| std::move(rangeObject), doc)); |
| } |
| |
| pdfShader->insertInt("ShadingType", shadingType); |
| pdfShader->insertName("ColorSpace", "DeviceRGB"); |
| |
| SkPDFDict pdfFunctionShader("Pattern"); |
| pdfFunctionShader.insertInt("PatternType", 2); |
| pdfFunctionShader.insertObject("Matrix", SkPDFUtils::MatrixToArray(finalMatrix)); |
| pdfFunctionShader.insertObject("Shading", std::move(pdfShader)); |
| return doc->emit(pdfFunctionShader); |
| } |
| |
| static SkPDFIndirectReference find_pdf_shader(SkPDFDocument* doc, |
| SkPDFGradientShader::Key key, |
| bool keyHasAlpha); |
| |
| static std::unique_ptr<SkPDFDict> get_gradient_resource_dict(SkPDFIndirectReference functionShader, |
| SkPDFIndirectReference gState) { |
| std::vector<SkPDFIndirectReference> patternShaders; |
| if (functionShader != SkPDFIndirectReference()) { |
| patternShaders.push_back(functionShader); |
| } |
| std::vector<SkPDFIndirectReference> graphicStates; |
| if (gState != SkPDFIndirectReference()) { |
| graphicStates.push_back(gState); |
| } |
| return SkPDFMakeResourceDict(std::move(graphicStates), |
| std::move(patternShaders), |
| std::vector<SkPDFIndirectReference>(), |
| std::vector<SkPDFIndirectReference>()); |
| } |
| |
| // Creates a content stream which fills the pattern P0 across bounds. |
| // @param gsIndex A graphics state resource index to apply, or <0 if no |
| // graphics state to apply. |
| static std::unique_ptr<SkStreamAsset> create_pattern_fill_content(int gsIndex, |
| int patternIndex, |
| SkRect& bounds) { |
| SkDynamicMemoryWStream content; |
| if (gsIndex >= 0) { |
| SkPDFUtils::ApplyGraphicState(gsIndex, &content); |
| } |
| SkPDFUtils::ApplyPattern(patternIndex, &content); |
| SkPDFUtils::AppendRectangle(bounds, &content); |
| SkPDFUtils::PaintPath(SkPaint::kFill_Style, SkPathFillType::kEvenOdd, &content); |
| return content.detachAsStream(); |
| } |
| |
| static bool gradient_has_alpha(const SkPDFGradientShader::Key& key) { |
| SkASSERT(key.fType != SkShader::kNone_GradientType); |
| for (int i = 0; i < key.fInfo.fColorCount; i++) { |
| if ((SkAlpha)SkColorGetA(key.fInfo.fColors[i]) != SK_AlphaOPAQUE) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| // warning: does not set fHash on new key. (Both callers need to change fields.) |
| static SkPDFGradientShader::Key clone_key(const SkPDFGradientShader::Key& k) { |
| SkPDFGradientShader::Key clone = { |
| k.fType, |
| k.fInfo, // change pointers later. |
| std::unique_ptr<SkColor[]>(new SkColor[k.fInfo.fColorCount]), |
| std::unique_ptr<SkScalar[]>(new SkScalar[k.fInfo.fColorCount]), |
| k.fCanvasTransform, |
| k.fShaderTransform, |
| k.fBBox, 0}; |
| clone.fInfo.fColors = clone.fColors.get(); |
| clone.fInfo.fColorOffsets = clone.fStops.get(); |
| for (int i = 0; i < clone.fInfo.fColorCount; i++) { |
| clone.fInfo.fColorOffsets[i] = k.fInfo.fColorOffsets[i]; |
| clone.fInfo.fColors[i] = k.fInfo.fColors[i]; |
| } |
| return clone; |
| } |
| |
| static SkPDFIndirectReference create_smask_graphic_state(SkPDFDocument* doc, |
| const SkPDFGradientShader::Key& state) { |
| SkASSERT(state.fType != SkShader::kNone_GradientType); |
| SkPDFGradientShader::Key luminosityState = clone_key(state); |
| for (int i = 0; i < luminosityState.fInfo.fColorCount; i++) { |
| SkAlpha alpha = SkColorGetA(luminosityState.fInfo.fColors[i]); |
| luminosityState.fInfo.fColors[i] = SkColorSetARGB(255, alpha, alpha, alpha); |
| } |
| luminosityState.fHash = hash(luminosityState); |
| |
| SkASSERT(!gradient_has_alpha(luminosityState)); |
| SkPDFIndirectReference luminosityShader = find_pdf_shader(doc, std::move(luminosityState), false); |
| std::unique_ptr<SkPDFDict> resources = get_gradient_resource_dict(luminosityShader, |
| SkPDFIndirectReference()); |
| SkRect bbox = SkRect::Make(state.fBBox); |
| SkPDFIndirectReference alphaMask = |
| SkPDFMakeFormXObject(doc, |
| create_pattern_fill_content(-1, luminosityShader.fValue, bbox), |
| SkPDFUtils::RectToArray(bbox), |
| std::move(resources), |
| SkMatrix::I(), |
| "DeviceRGB"); |
| return SkPDFGraphicState::GetSMaskGraphicState( |
| alphaMask, false, SkPDFGraphicState::kLuminosity_SMaskMode, doc); |
| } |
| |
| static SkPDFIndirectReference make_alpha_function_shader(SkPDFDocument* doc, |
| const SkPDFGradientShader::Key& state) { |
| SkASSERT(state.fType != SkShader::kNone_GradientType); |
| SkPDFGradientShader::Key opaqueState = clone_key(state); |
| for (int i = 0; i < opaqueState.fInfo.fColorCount; i++) { |
| opaqueState.fInfo.fColors[i] = SkColorSetA(opaqueState.fInfo.fColors[i], SK_AlphaOPAQUE); |
| } |
| opaqueState.fHash = hash(opaqueState); |
| |
| SkASSERT(!gradient_has_alpha(opaqueState)); |
| SkRect bbox = SkRect::Make(state.fBBox); |
| SkPDFIndirectReference colorShader = find_pdf_shader(doc, std::move(opaqueState), false); |
| if (!colorShader) { |
| return SkPDFIndirectReference(); |
| } |
| // Create resource dict with alpha graphics state as G0 and |
| // pattern shader as P0, then write content stream. |
| SkPDFIndirectReference alphaGsRef = create_smask_graphic_state(doc, state); |
| |
| std::unique_ptr<SkPDFDict> resourceDict = get_gradient_resource_dict(colorShader, alphaGsRef); |
| |
| std::unique_ptr<SkStreamAsset> colorStream = |
| create_pattern_fill_content(alphaGsRef.fValue, colorShader.fValue, bbox); |
| std::unique_ptr<SkPDFDict> alphaFunctionShader = SkPDFMakeDict(); |
| SkPDFUtils::PopulateTilingPatternDict(alphaFunctionShader.get(), bbox, |
| std::move(resourceDict), SkMatrix::I()); |
| return SkPDFStreamOut(std::move(alphaFunctionShader), std::move(colorStream), doc); |
| } |
| |
| static SkPDFGradientShader::Key make_key(const SkShader* shader, |
| const SkMatrix& canvasTransform, |
| const SkIRect& bbox) { |
| SkPDFGradientShader::Key key = { |
| SkShader::kNone_GradientType, |
| {0, nullptr, nullptr, {{0, 0}, {0, 0}}, {0, 0}, SkTileMode::kClamp, 0}, |
| nullptr, |
| nullptr, |
| canvasTransform, |
| SkPDFUtils::GetShaderLocalMatrix(shader), |
| bbox, 0}; |
| key.fType = shader->asAGradient(&key.fInfo); |
| SkASSERT(SkShader::kNone_GradientType != key.fType); |
| SkASSERT(key.fInfo.fColorCount > 0); |
| key.fColors.reset(new SkColor[key.fInfo.fColorCount]); |
| key.fStops.reset(new SkScalar[key.fInfo.fColorCount]); |
| key.fInfo.fColors = key.fColors.get(); |
| key.fInfo.fColorOffsets = key.fStops.get(); |
| (void)shader->asAGradient(&key.fInfo); |
| key.fHash = hash(key); |
| return key; |
| } |
| |
| static SkPDFIndirectReference find_pdf_shader(SkPDFDocument* doc, |
| SkPDFGradientShader::Key key, |
| bool keyHasAlpha) { |
| SkASSERT(gradient_has_alpha(key) == keyHasAlpha); |
| auto& gradientPatternMap = doc->fGradientPatternMap; |
| if (SkPDFIndirectReference* ptr = gradientPatternMap.find(key)) { |
| return *ptr; |
| } |
| SkPDFIndirectReference pdfShader; |
| if (keyHasAlpha) { |
| pdfShader = make_alpha_function_shader(doc, key); |
| } else { |
| pdfShader = make_function_shader(doc, key); |
| } |
| gradientPatternMap.set(std::move(key), pdfShader); |
| return pdfShader; |
| } |
| |
| SkPDFIndirectReference SkPDFGradientShader::Make(SkPDFDocument* doc, |
| SkShader* shader, |
| const SkMatrix& canvasTransform, |
| const SkIRect& bbox) { |
| SkASSERT(shader); |
| SkASSERT(SkShader::kNone_GradientType != shader->asAGradient(nullptr)); |
| SkPDFGradientShader::Key key = make_key(shader, canvasTransform, bbox); |
| bool alpha = gradient_has_alpha(key); |
| return find_pdf_shader(doc, std::move(key), alpha); |
| } |
