/* * Copyright 2022 Google LLC * * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ #include "src/gpu/graphite/render/AnalyticRRectRenderStep.h" #include "src/base/SkVx.h" #include "src/core/SkRRectPriv.h" #include "src/gpu/graphite/DrawParams.h" #include "src/gpu/graphite/DrawWriter.h" #include "src/gpu/graphite/render/CommonDepthStencilSettings.h" // This RenderStep is flexible and can draw filled rectangles, filled quadrilaterals with per-edge // AA, filled rounded rectangles with arbitrary corner radii, stroked rectangles with any join, // stroked lines with any cap, stroked rounded rectangles with circular corners (each corner can be // different or square), hairline rectangles, hairline lines, and hairline rounded rectangles with // arbitrary corners. // // We combine all of these together to maximize batching across simple geometric draws and reduce // the number pipeline specializations. Additionally, these primitives are the most common // operations and help us avoid triggering MSAA. // // Each of these "primitives" is represented by a single instance. The instance attributes are // flexible enough to describe any of the above shapes without relying on uniforms to define its // operation. The attributes encode shape as follows: // // float4 xRadiiOrFlags - if any components is > 0, the instance represents a filled round rect // with elliptical corners and these values specify the X radii in top-left CW order. // Otherwise, if .x < -1, the instance represents a stroked or hairline [round] rect or line, // where .y differentiates hairline vs. stroke. If .y is negative, then it is a hairline [round] // rect and xRadiiOrFlags stores (-2 - X radii); if .y is zero, it is a regular stroked [round] // rect; if .y is positive, then it is a stroked *or* hairline line. For .y >= 0, .z holds the // stroke radius and .w stores the join limit (matching StrokeStyle's conventions). // Lastly, if -1 <= .x <= 0, it's a filled quadrilateral with per-edge AA defined by each by the // component: aa != 0. // float4 radiiOrQuadXs - if in filled round rect or hairline [round] rect mode, these values // provide the Y radii in top-left CW order. If in stroked [round] rect mode, these values // provide the circular corner radii (same order). Otherwise, when in per-edge quad mode, these // values provide the X coordinates of the quadrilateral (same order). // float4 ltrbOrQuadYs - if in filled round rect mode or stroked [round] rect mode, these values // define the LTRB edge coordinates of the rectangle surrounding the round rect (or the // rect itself when the radii are 0s). In stroked line mode, LTRB is treated as (x0,y0) and // (x1,y1) that defines the line. Otherwise, in per-edge quad mode, these values provide // the Y coordinates of the quadrilateral. // // From the other direction, shapes produce instance values like: // - filled rect: [-1 -1 -1 -1] [L R R L] [T T B B] // - stroked rect: [-2 0 stroke join] [0 0 0 0] [L T R B] // - hairline rect: [-2 -2 -2 -2] [0 0 0 0] [L T R B] // - filled rrect: [xRadii(tl,tr,br,bl)] [yRadii(tl,tr,br,bl)] [L T R B] // - stroked rrect: [-2 0 stroke join] [radii(tl,tr,br,bl)] [L T R B] // - hairline rrect: [-2-xRadii(tl,tr,br,bl)] [radii(tl,tr,br,bl)] [L T R B] // - filled line: N/A, discarded higher in the stack // - stroked line: [-2 1 stroke cap] [0 0 0 0] [x0,y0,x1,y1] // - hairline line: [-2 1 0 1] [0 0 0 0] [x0,y0,x1,y1] // - per-edge quad: [aa(t,r,b,l) ? -1 : 0] [xs(tl,tr,br,bl)] [ys(tl,tr,br,bl)] // // This encoding relies on the fact that a valid SkRRect with all x radii equal to 0 must have // y radii equal to 0 (so it's a rectangle and we can treat it as a quadrilateral with // all edges AA'ed). This avoids other encodings' inability to represent a quad with all edges // anti-aliased (e.g. checking for negatives in xRadiiOrFlags to turn on per-edge mode). // // From this encoding, data can be unpacked for each corner, which are equivalent under // rotational symmetry. A corner can have an outer curve, be mitered, or be beveled. It can // have an inner curve, an inner miter, or fill the interior. Per-edge quads are always mitered // and fill the interior, but the vertices are placed such that the edge coverage ramps can // collapse to 0 area on non-AA edges. // // The vertices that describe each corner are placed so that edges, miters, and bevels calculate // coverage by interpolating a varying and then clamping in the fragment shader. Triangles that // cover the inner and outer curves calculate distance to the curve within the fragment shader. // // See https://docs.google.com/presentation/d/1MCPstNsSlDBhR8CrsJo0r-cZNbu-sEJEvU9W94GOJoY/edit?usp=sharing // for diagrams and explanation of how the geometry is defined. // // AnalyticRRectRenderStep uses the common technique of approximating distance to the level set by // one expansion of the Taylor's series for the level set's equation. Given a level set function // C(x,y), this amounts to calculating C(px,py)/|∇C(px,py)|. For the straight edges the level set // is linear and calculated in the vertex shader and then interpolated exactly over the rectangle. // This provides distances to all four exterior edges within the fragment shader and allows it to // reconstruct a relative position per elliptical corner. Unfortunately this requires the fragment // shader to calculate the length of the gradient for straight edges instead of interpolating // exact device-space distance. // // All four corner radii are potentially evaluated by the fragment shader although each corner's // coverage is only calculated when the pixel is within the bounding box of its quadrant. For fills // and simple strokes it's theoretically valid to have each pixel calculate a single corner's // coverage that was controlled via the vertex shader. However, testing all four corners is // necessary in order to correctly handle self-intersecting stroke interiors. Similarly, all four // edges must be evaluated in order to handle extremely thin shapes; whereas often you could get // away with tracking a single edge distance per pixel. // // Analytic derivatives are used so that a single pipeline can be used regardless of HW derivative // support or for geometry that would prove difficult for forward differencing. The device-space // gradient for ellipses is calculated per-pixel by transforming a per-pixel local gradient vector // with the Jacobian of the inverse local-to-device transform: // // (px,py) is the projected point of (u,v) transformed by a 3x3 matrix, M: // [x(u,v) / w(u,v)] [x] [m00 m01 m02] [u] // (px,py) = [y(u,v) / w(u,v)] where [y] = [m10 m11 m12]X[v] = M*(u,v,1) // [w] [m20 m21 m22] [1] // // C(px,py) can be defined in terms of a local Cl(u,v) as C(px,py) = Cl(p^-1(px,py)), where p^-1 = // // [x'(px,py) / w'(px,py)] [x'] [m00' m01' * m02'] [px] // (u,v) = [y'(px,py) / w'(px,py)] where [y'] = [m10' m11' * m12']X[py] = M^-1*(px,py,0,1) // [w'] [m20' m21' * m22'] [ 1] // // Note that if the 3x3 M was arrived by dropping the 3rd row and column from a 4x4 since we assume // a local 3rd coordinate of 0, M^-1 is not equal to the 4x4 inverse with dropped rows and columns. // // Using the chain rule, then ∇C(px,py) // = ∇Cl(u,v)X[1/w'(px,py) 0 -x'(px,py)/w'(px,py)^2] [m00' m01'] // [ 0 1/w'(px,py) -y'(px,py)/w'(px,py)^2]X[m10' m11'] // [m20' m21'] // // = 1/w'(px,py)*∇Cl(u,v)X[1 0 -x'(px,py)/w'(px,py)] [m00' m01'] // [0 1 -y'(px,py)/w'(px,py)]X[m10' m11'] // [m20' m21'] // // = w(u,v)*∇Cl(u,v)X[1 0 0 -u] [m00' m01'] // [0 1 0 -v]X[m10' m11'] // [m20' m21'] // // = w(u,v)*∇Cl(u,v)X[m00'-m20'u m01'-m21'u] // [m10'-m20'v m11'-m21'v] // // The vertex shader calculates the rightmost 2x2 matrix and interpolates it across the shape since // each component is linear in (u,v). ∇Cl(u,v) is evaluated per pixel in the fragment shader and // depends on which corner and edge being evaluated. w(u,v) is the device-space W coordinate, so // its reciprocal is provided in sk_FragCoord.w. namespace skgpu::graphite { using AAFlags = EdgeAAQuad::Flags; static skvx::float4 load_x_radii(const SkRRect& rrect) { return skvx::float4{rrect.radii(SkRRect::kUpperLeft_Corner).fX, rrect.radii(SkRRect::kUpperRight_Corner).fX, rrect.radii(SkRRect::kLowerRight_Corner).fX, rrect.radii(SkRRect::kLowerLeft_Corner).fX}; } static skvx::float4 load_y_radii(const SkRRect& rrect) { return skvx::float4{rrect.radii(SkRRect::kUpperLeft_Corner).fY, rrect.radii(SkRRect::kUpperRight_Corner).fY, rrect.radii(SkRRect::kLowerRight_Corner).fY, rrect.radii(SkRRect::kLowerLeft_Corner).fY}; } static bool opposite_insets_intersect(const SkRRect& rrect, float strokeRadius, float aaRadius) { // One AA inset per side const float maxInset = strokeRadius + 2.f * aaRadius; return // Horizontal insets would intersect opposite corner's curve maxInset >= rrect.width() - rrect.radii(SkRRect::kLowerLeft_Corner).fX || maxInset >= rrect.width() - rrect.radii(SkRRect::kLowerRight_Corner).fX || maxInset >= rrect.width() - rrect.radii(SkRRect::kUpperLeft_Corner).fX || maxInset >= rrect.width() - rrect.radii(SkRRect::kUpperRight_Corner).fX || // Vertical insets would intersect opposite corner's curve maxInset >= rrect.height() - rrect.radii(SkRRect::kLowerLeft_Corner).fY || maxInset >= rrect.height() - rrect.radii(SkRRect::kLowerRight_Corner).fY || maxInset >= rrect.height() - rrect.radii(SkRRect::kUpperLeft_Corner).fY || maxInset >= rrect.height() - rrect.radii(SkRRect::kUpperRight_Corner).fY; } static bool opposite_insets_intersect(const Rect& rect, float strokeRadius, float aaRadius) { return any(rect.size() <= 2.f * (strokeRadius + aaRadius)); } static bool opposite_insets_intersect(const Geometry& geometry, float strokeRadius, float aaRadius) { if (geometry.isEdgeAAQuad()) { SkASSERT(strokeRadius == 0.f); const EdgeAAQuad& quad = geometry.edgeAAQuad(); if (quad.edgeFlags() == AAFlags::kNone) { // If all edges are non-AA, there won't be any insetting. This allows completely non-AA // quads to use the fill triangles for simpler fragment shader work. return false; } else if (quad.isRect() && quad.edgeFlags() == AAFlags::kAll) { return opposite_insets_intersect(quad.bounds(), 0.f, aaRadius); } else { // Quads with mixed AA edges are tiles where non-AA edges must seam perfectly together. // If we were to inset along just the axis with AA at a corner, two adjacent quads could // arrive at slightly different inset coordinates and then we wouldn't have a perfect // mesh. Forcing insets to snap to the center means all non-AA edges are formed solely // by the original quad coordinates and should seam perfectly assuming perfect input. // The only downside to this is the fill triangles cannot be used since they would // partially extend into the coverage ramp from adjacent AA edges. return true; } } else { const Shape& shape = geometry.shape(); if (shape.isLine()) { return strokeRadius <= aaRadius; } else if (shape.isRect()) { return opposite_insets_intersect(shape.rect(), strokeRadius, aaRadius); } else { SkASSERT(shape.isRRect()); return opposite_insets_intersect(shape.rrect(), strokeRadius, aaRadius); } } } static bool is_clockwise(const EdgeAAQuad& quad) { if (quad.isRect()) { return true; // by construction, these are always locally clockwise } // This assumes that each corner has a consistent winding, which is the case for convex inputs, // which is an assumption of the per-edge AA API. Check the sign of cross product between the // first two edges. const skvx::float4& xs = quad.xs(); const skvx::float4& ys = quad.ys(); float winding = (xs[0] - xs[3])*(ys[1] - ys[0]) - (ys[0] - ys[3])*(xs[1] - xs[0]); if (winding == 0.f) { // The input possibly forms a triangle with duplicate vertices, so check the opposite corner winding = (xs[2] - xs[1])*(ys[3] - ys[2]) - (ys[2] - ys[1])*(xs[3] - xs[2]); } // At this point if winding is < 0, the quad's vertices are CCW. If it's still 0, the vertices // form a line, in which case the vertex shader constructs a correct CW winding. Otherwise, // the quad or triangle vertices produce a positive winding and are CW. return winding >= 0.f; } static skvx::float2 quad_center(const EdgeAAQuad& quad) { // The center of the bounding box is *not* a good center to use. Take the average of the // four points instead (which is slightly biased if they form a triangle, but still okay). return skvx::float2(dot(quad.xs(), skvx::float4(0.25f)), dot(quad.ys(), skvx::float4(0.25f))); } // Represents the per-vertex attributes used in each instance. struct Vertex { SkV2 fPosition; SkV2 fNormal; float fNormalScale; float fCenterWeight; }; // Allowed values for the center weight instance value (selected at record time based on style // and transform), and are defined such that when (insance-weight > vertex-weight) is true, the // vertex should be snapped to the center instead of its regular calculation. static constexpr float kSolidInterior = 1.f; static constexpr float kStrokeInterior = 0.f; static constexpr float kFilledStrokeInterior = -1.f; // Special value for local AA radius to signal when the self-intersections of a stroke interior // need extra calculations in the vertex shader. static constexpr float kComplexAAInsets = -1.f; static constexpr int kCornerVertexCount = 9; // sk_VertexID is divided by this in SkSL static constexpr int kVertexCount = 4 * kCornerVertexCount; static constexpr int kIndexCount = 69; static void write_index_buffer(VertexWriter writer) { static constexpr uint16_t kTL = 0 * kCornerVertexCount; static constexpr uint16_t kTR = 1 * kCornerVertexCount; static constexpr uint16_t kBR = 2 * kCornerVertexCount; static constexpr uint16_t kBL = 3 * kCornerVertexCount; static const uint16_t kIndices[kIndexCount] = { // Exterior AA ramp outset kTL+0,kTL+4,kTL+1,kTL+5,kTL+2,kTL+3,kTL+5, kTR+0,kTR+4,kTR+1,kTR+5,kTR+2,kTR+3,kTR+5, kBR+0,kBR+4,kBR+1,kBR+5,kBR+2,kBR+3,kBR+5, kBL+0,kBL+4,kBL+1,kBL+5,kBL+2,kBL+3,kBL+5, kTL+0,kTL+4, // close and jump to next strip // Outer to inner edges kTL+4,kTL+6,kTL+5,kTL+7, kTR+4,kTR+6,kTR+5,kTR+7, kBR+4,kBR+6,kBR+5,kBR+7, kBL+4,kBL+6,kBL+5,kBL+7, kTL+4,kTL+6, // close and jump to next strip // Fill triangles kTL+6,kTL+8,kTL+7, kTL+7,kTR+8, kTR+6,kTR+8,kTR+7, kTR+7,kBR+8, kBR+6,kBR+8,kBR+7, kBR+7,kBL+8, kBL+6,kBL+8,kBL+7, kBL+7,kTL+8, kTL+6 // close }; if (writer) { writer << kIndices; } // otherwise static buffer creation failed, so do nothing; Context initialization will fail. } static void write_vertex_buffer(VertexWriter writer) { // Allowed values for the normal scale attribute. +1 signals a device-space outset along the // normal away from the outer edge of the stroke. 0 signals no outset, but placed on the outer // edge of the stroke. -1 signals a local inset along the normal from the inner edge. static constexpr float kOutset = 1.0; static constexpr float kInset = -1.0; static constexpr float kCenter = 1.f; // "true" as a float // Zero, but named this way to help call out non-zero parameters. static constexpr float _______ = 0.f; static constexpr float kHR2 = 0.5f * SK_FloatSqrt2; // "half root 2" // This template is repeated 4 times in the vertex buffer, for each of the four corners. // The vertex ID is used to lookup per-corner instance properties such as corner radii or // positions, but otherwise this vertex data produces a consistent clockwise mesh from // TL -> TR -> BR -> BL. static constexpr Vertex kCornerTemplate[kCornerVertexCount] = { // Device-space AA outsets from outer curve { {1.0f, 0.0f}, {1.0f, 0.0f}, kOutset, _______ }, { {1.0f, 0.0f}, {kHR2, kHR2}, kOutset, _______ }, { {0.0f, 1.0f}, {kHR2, kHR2}, kOutset, _______ }, { {0.0f, 1.0f}, {0.0f, 1.0f}, kOutset, _______ }, // Outer anchors (no local or device-space normal outset) { {1.0f, 0.0f}, {kHR2, kHR2}, _______, _______ }, { {0.0f, 1.0f}, {kHR2, kHR2}, _______, _______ }, // Inner curve (with additional AA inset in the common case) { {1.0f, 0.0f}, {1.0f, 0.0f}, kInset, _______ }, { {0.0f, 1.0f}, {0.0f, 1.0f}, kInset, _______ }, // Center filling vertices (equal to inner AA insets unless 'center' triggers a fill). // TODO: On backends that support "cull" distances (and with SkSL support), these vertices // and their corresponding triangles can be completely removed. The inset vertices can // set their cull distance value to cause all filling triangles to be discarded or not // depending on the instance's style. { {1.0f, 0.0f}, {1.0f, 0.0f}, kInset, kCenter }, }; if (writer) { writer << kCornerTemplate // TL << kCornerTemplate // TR << kCornerTemplate // BR << kCornerTemplate; // BL } // otherwise static buffer creation failed, so do nothing; Context initialization will fail. } AnalyticRRectRenderStep::AnalyticRRectRenderStep(StaticBufferManager* bufferManager) : RenderStep("AnalyticRRectRenderStep", "", Flags::kPerformsShading | Flags::kEmitsCoverage | Flags::kOutsetBoundsForAA, /*uniforms=*/{}, PrimitiveType::kTriangleStrip, kDirectDepthGreaterPass, /*vertexAttrs=*/{ {"position", VertexAttribType::kFloat2, SkSLType::kFloat2}, {"normal", VertexAttribType::kFloat2, SkSLType::kFloat2}, // TODO: These values are all +1/0/-1, or +1/0, so could be packed // much more densely than as three floats. {"normalScale", VertexAttribType::kFloat, SkSLType::kFloat}, {"centerWeight", VertexAttribType::kFloat, SkSLType::kFloat} }, /*instanceAttrs=*/ {{"xRadiiOrFlags", VertexAttribType::kFloat4, SkSLType::kFloat4}, {"radiiOrQuadXs", VertexAttribType::kFloat4, SkSLType::kFloat4}, {"ltrbOrQuadYs", VertexAttribType::kFloat4, SkSLType::kFloat4}, // XY stores center of rrect in local coords. Z and W store values to // control interior fill behavior. Z can be -1, 0, or 1: // -1: A stroked interior where AA insets overlap, but isn't solid. // 0: A stroked interior with no complications. // 1: A solid interior (fill or sufficiently large stroke width). // W specifies the size of the AA inset if it's >= 0, or signals that // the inner curves intersect in a complex manner (rare). {"center", VertexAttribType::kFloat4, SkSLType::kFloat4}, // TODO: pack depth and ssbo index into one 32-bit attribute, if we can // go without needing both render step and paint ssbo index attributes. {"depth", VertexAttribType::kFloat, SkSLType::kFloat}, {"ssboIndices", VertexAttribType::kUShort2, SkSLType::kUShort2}, {"mat0", VertexAttribType::kFloat3, SkSLType::kFloat3}, {"mat1", VertexAttribType::kFloat3, SkSLType::kFloat3}, {"mat2", VertexAttribType::kFloat3, SkSLType::kFloat3}}, /*varyings=*/{ // TODO: If the inverse transform is part of the draw's SSBO, we can // reconstruct the Jacobian in the fragment shader using the existing // local coordinates varying {"jacobian", SkSLType::kFloat4}, // float2x2 // Distance to LTRB edges of unstroked shape. Depending on // 'perPixelControl' these will either be local or device-space values. {"edgeDistances", SkSLType::kFloat4}, // distance to LTRB edges // TODO: These are constant for all fragments for a given instance, // could we store them in the draw's SSBO? {"xRadii", SkSLType::kFloat4}, {"yRadii", SkSLType::kFloat4}, // Matches the StrokeStyle struct (X is radius, Y < 0 is round join, // Y = 0 is bevel, Y > 0 is miter join). // TODO: These could easily be considered part of the draw's uniforms. {"strokeParams", SkSLType::kFloat2}, // 'perPixelControl' is a tightly packed description of how to // evaluate the possible edges that influence coverage in a pixel. // The decision points and encoded values are spread across X and Y // so that they are consistent regardless of whether or not MSAA is // used and does not require centroid sampling. // // The signs of values are used to determine the type of coverage to // calculate in the fragment shader and depending on the state, extra // varying state is encoded in the fields: // - A positive X value overrides all per-pixel coverage calculations // and sets the pixel to full coverage. Y is ignored in this case. // - A zero X value represents a solid interior shape. // - X much less than 0 represents bidirectional coverage for a // stroke, using a sufficiently negative value to avoid // extrapolation from fill triangles. For actual shapes with // bidirectional coverage, the fill triangles are zero area. // // - Y much greater than 0 takes precedence over the latter two X // rules and signals that 'edgeDistances' holds device-space values // and does not require additional per-pixel calculations. The // coverage scale is encoded as (1+scale*w) and the bias is // reconstructed from that. X is always 0 for non-fill triangles // since device-space edge distance is only used for solid interiors // - Otherwise, any negative Y value represents an additional // reduction in coverage due to a device-space outset. It is clamped // below 0 to avoid adding coverage from extrapolation. {"perPixelControl", SkSLType::kFloat2}, }) { // Initialize the static buffers we'll use when recording draw calls. // NOTE: Each instance of this RenderStep gets its own copy of the data. Since there should only // ever be one AnalyticRRectRenderStep at a time, this shouldn't be an issue. write_vertex_buffer(bufferManager->getVertexWriter(sizeof(Vertex) * kVertexCount, &fVertexBuffer)); write_index_buffer(bufferManager->getIndexWriter(sizeof(uint16_t) * kIndexCount, &fIndexBuffer)); } AnalyticRRectRenderStep::~AnalyticRRectRenderStep() {} std::string AnalyticRRectRenderStep::vertexSkSL() const { // Returns the body of a vertex function, which must define a float4 devPosition variable and // must write to an already-defined float2 stepLocalCoords variable. return "float4 devPosition = analytic_rrect_vertex_fn(" // Vertex Attributes "position, normal, normalScale, centerWeight, " // Instance Attributes "xRadiiOrFlags, radiiOrQuadXs, ltrbOrQuadYs, center, depth, " "float3x3(mat0, mat1, mat2), " // Varyings "jacobian, edgeDistances, xRadii, yRadii, strokeParams, perPixelControl, " // Render Step "stepLocalCoords);\n"; } const char* AnalyticRRectRenderStep::fragmentCoverageSkSL() const { // The returned SkSL must write its coverage into a 'half4 outputCoverage' variable (defined in // the calling code) with the actual coverage splatted out into all four channels. return "outputCoverage = analytic_rrect_coverage_fn(sk_FragCoord, " "jacobian, " "edgeDistances, " "xRadii, " "yRadii, " "strokeParams, " "perPixelControl);"; } void AnalyticRRectRenderStep::writeVertices(DrawWriter* writer, const DrawParams& params, skvx::ushort2 ssboIndices) const { SkASSERT(params.geometry().isShape() || params.geometry().isEdgeAAQuad()); DrawWriter::Instances instance{*writer, fVertexBuffer, fIndexBuffer, kIndexCount}; auto vw = instance.append(1); // The bounds of a rect is the rect, and the bounds of a rrect is tight (== SkRRect::getRect()). Rect bounds = params.geometry().bounds(); // aaRadius will be set to a negative value to signal a complex self-intersection that has to // be calculated in the vertex shader. float aaRadius = params.transform().localAARadius(bounds); float strokeInset = 0.f; float centerWeight = kSolidInterior; if (params.isStroke()) { // EdgeAAQuads are not stroked so we know it's a Shape, but we support rects, rrects, and // lines that all need to be converted to the same form. const Shape& shape = params.geometry().shape(); SkASSERT(params.strokeStyle().halfWidth() >= 0.f); SkASSERT(shape.isRect() || shape.isLine() || params.strokeStyle().halfWidth() == 0.f || (shape.isRRect() && SkRRectPriv::AllCornersCircular(shape.rrect()))); float strokeRadius = params.strokeStyle().halfWidth(); skvx::float2 size = shape.isLine() ? skvx::float2(length(shape.p1() - shape.p0()), 0.f) : bounds.size(); // rect or [r]rect skvx::float2 innerGap = size - 2.f * params.strokeStyle().halfWidth(); if (any(innerGap <= 0.f) && strokeRadius > 0.f) { // AA inset intersections are measured from the *outset* and remain marked as "solid" strokeInset = -strokeRadius; } else { // This will be upgraded to kFilledStrokeInterior if insets intersect centerWeight = kStrokeInterior; strokeInset = strokeRadius; } skvx::float4 xRadii = shape.isRRect() ? load_x_radii(shape.rrect()) : skvx::float4(0.f); if (strokeRadius > 0.f || shape.isLine()) { // Regular strokes only need to upload 4 corner radii; hairline lines can be uploaded in // the same manner since it has no real corner radii. float joinStyle = params.strokeStyle().joinLimit(); float lineFlag = shape.isLine() ? 1.f : 0.f; auto empty = size == 0.f; // Points and lines produce caps instead of joins. However, the capped geometry is // visually equivalent to a joined, stroked [r]rect of the paired join style. if (shape.isLine() || all(empty)) { // However, butt-cap points are defined not to produce any geometry, so that combo // should have been rejected earlier. SkASSERT(shape.isLine() || params.strokeStyle().cap() != SkPaint::kButt_Cap); switch(params.strokeStyle().cap()) { case SkPaint::kRound_Cap: joinStyle = -1.f; break; // round cap == round join case SkPaint::kButt_Cap: joinStyle = 0.f; break; // butt cap == bevel join case SkPaint::kSquare_Cap: joinStyle = 1.f; break; // square cap == miter join } } else if (params.strokeStyle().isMiterJoin()) { // Normal corners are 90-degrees so become beveled if the miter limit is < sqrt(2). // If the [r]rect has a width or height of 0, the corners are actually 180-degrees, // so the must always be beveled (or, equivalently, butt-capped). if (params.strokeStyle().miterLimit() < SK_ScalarSqrt2 || any(empty)) { joinStyle = 0.f; // == bevel (or butt if width or height are zero) } else { // Discard actual miter limit because a 90-degree corner never exceeds it. joinStyle = 1.f; } } // else no join style correction needed for non-empty geometry or round joins // Write a negative value outside [-1, 0] to signal a stroked shape, the line flag, then // the style params, followed by corner radii and coords. vw << -2.f << lineFlag << strokeRadius << joinStyle << xRadii << (shape.isLine() ? shape.line() : bounds.ltrb()); } else { // Write -2 - cornerRadii to encode the X radii in such a way to trigger stroking but // guarantee the 2nd field is non-zero to signal hairline. Then we upload Y radii as // well to allow for elliptical hairlines. skvx::float4 yRadii = shape.isRRect() ? load_y_radii(shape.rrect()) : skvx::float4(0.f); vw << (-2.f - xRadii) << yRadii << bounds.ltrb(); } } else { // Empty fills should not have been recorded at all. SkASSERT(!bounds.isEmptyNegativeOrNaN()); if (params.geometry().isEdgeAAQuad()) { // NOTE: If quad.isRect() && quad.edgeFlags() == kAll, the written data is identical to // Shape.isRect() case below. const EdgeAAQuad& quad = params.geometry().edgeAAQuad(); // If all edges are non-AA, set localAARadius to 0 so that the fill triangles cover the // entire shape. Otherwise leave it as-is for the full AA rect case; in the event it's // mixed-AA or a quad, it'll be converted to complex insets down below. if (quad.edgeFlags() == EdgeAAQuad::Flags::kNone) { aaRadius = 0.f; } // -1 for AA on, 0 for AA off auto edgeSigns = skvx::float4{quad.edgeFlags() & AAFlags::kLeft ? -1.f : 0.f, quad.edgeFlags() & AAFlags::kTop ? -1.f : 0.f, quad.edgeFlags() & AAFlags::kRight ? -1.f : 0.f, quad.edgeFlags() & AAFlags::kBottom ? -1.f : 0.f}; // The vertex shader expects points to be in clockwise order. EdgeAAQuad is the only // shape that *might* have counter-clockwise input. if (is_clockwise(quad)) { vw << edgeSigns << quad.xs() << quad.ys(); } else { vw << skvx::shuffle<2,1,0,3>(edgeSigns) // swap left and right AA bits << skvx::shuffle<1,0,3,2>(quad.xs()) // swap TL with TR, and BL with BR << skvx::shuffle<1,0,3,2>(quad.ys()); // "" } } else { const Shape& shape = params.geometry().shape(); // Filled lines are empty by definition, so they shouldn't have been recorded SkASSERT(!shape.isLine()); if (shape.isRect() || (shape.isRRect() && shape.rrect().isRect())) { // Rectangles (or rectangles embedded in an SkRRect) are converted to the // quadrilateral case, but with all edges anti-aliased (== -1). skvx::float4 ltrb = bounds.ltrb(); vw << /*edge flags*/ skvx::float4(-1.f) << /*xs*/ skvx::shuffle<0,2,2,0>(ltrb) << /*ys*/ skvx::shuffle<1,1,3,3>(ltrb); } else { // A filled rounded rectangle, so make sure at least one corner radii > 0 or the // shader won't detect it as a rounded rect. SkASSERT(any(load_x_radii(shape.rrect()) > 0.f)); vw << load_x_radii(shape.rrect()) << load_y_radii(shape.rrect()) << bounds.ltrb(); } } } if (opposite_insets_intersect(params.geometry(), strokeInset, aaRadius)) { aaRadius = kComplexAAInsets; if (centerWeight == kStrokeInterior) { centerWeight = kFilledStrokeInterior; } } // All instance types share the remaining instance attribute definitions const SkM44& m = params.transform().matrix(); auto center = params.geometry().isEdgeAAQuad() ? quad_center(params.geometry().edgeAAQuad()) : bounds.center(); vw << center << centerWeight << aaRadius << params.order().depthAsFloat() << ssboIndices << m.rc(0,0) << m.rc(1,0) << m.rc(3,0) // mat0 << m.rc(0,1) << m.rc(1,1) << m.rc(3,1) // mat1 << m.rc(0,3) << m.rc(1,3) << m.rc(3,3); // mat2 } void AnalyticRRectRenderStep::writeUniformsAndTextures(const DrawParams&, PipelineDataGatherer*) const { // All data is uploaded as instance attributes, so no uniforms are needed. } } // namespace skgpu::graphite