blob: 3df11cafe5454f4e50f5766ede1dde67a8ca585d [file] [log] [blame]
/*
* Copyright 2018 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "src/gpu/geometry/GrQuad.h"
#include "include/core/SkMatrix.h"
using V4f = skvx::Vec<4, float>;
static bool aa_affects_rect(float ql, float qt, float qr, float qb) {
return !SkScalarIsInt(ql) || !SkScalarIsInt(qr) || !SkScalarIsInt(qt) || !SkScalarIsInt(qb);
}
static void map_rect_translate_scale(const SkRect& rect, const SkMatrix& m,
V4f* xs, V4f* ys) {
SkMatrix::TypeMask tm = m.getType();
SkASSERT(tm <= (SkMatrix::kScale_Mask | SkMatrix::kTranslate_Mask));
V4f r = V4f::Load(&rect);
if (tm > SkMatrix::kIdentity_Mask) {
const V4f t{m.getTranslateX(), m.getTranslateY(), m.getTranslateX(), m.getTranslateY()};
if (tm <= SkMatrix::kTranslate_Mask) {
r += t;
} else {
const V4f s{m.getScaleX(), m.getScaleY(), m.getScaleX(), m.getScaleY()};
r = r * s + t;
}
}
*xs = skvx::shuffle<0, 0, 2, 2>(r);
*ys = skvx::shuffle<1, 3, 1, 3>(r);
}
static void map_quad_general(const V4f& qx, const V4f& qy, const SkMatrix& m,
V4f* xs, V4f* ys, V4f* ws) {
*xs = mad(m.getScaleX(), qx, mad(m.getSkewX(), qy, m.getTranslateX()));
*ys = mad(m.getSkewY(), qx, mad(m.getScaleY(), qy, m.getTranslateY()));
if (m.hasPerspective()) {
V4f w = mad(m.getPerspX(), qx,
mad(m.getPerspY(), qy, m.get(SkMatrix::kMPersp2)));
if (ws) {
// Output the calculated w coordinates
*ws = w;
} else {
// Apply perspective division immediately
V4f iw = 1.f / w;
*xs *= iw;
*ys *= iw;
}
} else if (ws) {
*ws = 1.f;
}
}
static void map_rect_general(const SkRect& rect, const SkMatrix& matrix,
V4f* xs, V4f* ys, V4f* ws) {
V4f rx{rect.fLeft, rect.fLeft, rect.fRight, rect.fRight};
V4f ry{rect.fTop, rect.fBottom, rect.fTop, rect.fBottom};
map_quad_general(rx, ry, matrix, xs, ys, ws);
}
// Rearranges (top-left, top-right, bottom-right, bottom-left) ordered skQuadPts into xs and ys
// ordered (top-left, bottom-left, top-right, bottom-right)
static void rearrange_sk_to_gr_points(const SkPoint skQuadPts[4], V4f* xs, V4f* ys) {
*xs = V4f{skQuadPts[0].fX, skQuadPts[3].fX, skQuadPts[1].fX, skQuadPts[2].fX};
*ys = V4f{skQuadPts[0].fY, skQuadPts[3].fY, skQuadPts[1].fY, skQuadPts[2].fY};
}
// If an SkRect is transformed by this matrix, what class of quad is required to represent it.
static GrQuad::Type quad_type_for_transformed_rect(const SkMatrix& matrix) {
if (matrix.rectStaysRect()) {
return GrQuad::Type::kAxisAligned;
} else if (matrix.preservesRightAngles()) {
return GrQuad::Type::kRectilinear;
} else if (matrix.hasPerspective()) {
return GrQuad::Type::kPerspective;
} else {
return GrQuad::Type::kGeneral;
}
}
// Perform minimal analysis of 'pts' (which are suitable for MakeFromSkQuad), and determine a
// quad type that will be as minimally general as possible.
static GrQuad::Type quad_type_for_points(const SkPoint pts[4], const SkMatrix& matrix) {
if (matrix.hasPerspective()) {
return GrQuad::Type::kPerspective;
}
// If 'pts' was formed by SkRect::toQuad() and not transformed further, it is safe to use the
// quad type derived from 'matrix'. Otherwise don't waste any more time and assume kStandard
// (most general 2D quad).
if ((pts[0].fX == pts[3].fX && pts[1].fX == pts[2].fX) &&
(pts[0].fY == pts[1].fY && pts[2].fY == pts[3].fY)) {
return quad_type_for_transformed_rect(matrix);
} else {
return GrQuad::Type::kGeneral;
}
}
GrQuad GrQuad::MakeFromRect(const SkRect& rect, const SkMatrix& m) {
V4f x, y, w;
SkMatrix::TypeMask tm = m.getType();
Type type;
if (tm <= (SkMatrix::kScale_Mask | SkMatrix::kTranslate_Mask)) {
map_rect_translate_scale(rect, m, &x, &y);
w = 1.f;
type = Type::kAxisAligned;
} else {
map_rect_general(rect, m, &x, &y, &w);
type = quad_type_for_transformed_rect(m);
}
return GrQuad(x, y, w, type);
}
GrQuad GrQuad::MakeFromSkQuad(const SkPoint pts[4], const SkMatrix& matrix) {
V4f xs, ys;
rearrange_sk_to_gr_points(pts, &xs, &ys);
Type type = quad_type_for_points(pts, matrix);
if (matrix.isIdentity()) {
return GrQuad(xs, ys, 1.f, type);
} else {
V4f mx, my, mw;
map_quad_general(xs, ys, matrix, &mx, &my, &mw);
return GrQuad(mx, my, mw, type);
}
}
bool GrQuad::aaHasEffectOnRect() const {
SkASSERT(this->quadType() == Type::kAxisAligned);
// If rect, ws must all be 1s so no need to divide
return aa_affects_rect(fX[0], fY[0], fX[3], fY[3]);
}
bool GrQuad::asRect(SkRect* rect) const {
if (this->quadType() != Type::kAxisAligned) {
return false;
}
*rect = this->bounds();
// v0 at the geometric top-left is unique amongst axis-aligned vertex orders
// (90, 180, 270 rotations or axis flips all move v0).
return fX[0] == rect->fLeft && fY[0] == rect->fTop;
}