cdalton | 93a379b | 2016-05-11 13:58:08 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2016 Google Inc. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license that can be |
| 5 | * found in the LICENSE file. |
| 6 | */ |
| 7 | |
| 8 | |
| 9 | #ifndef GrStencilSettings_DEFINED |
| 10 | #define GrStencilSettings_DEFINED |
| 11 | |
| 12 | #include "GrUserStencilSettings.h" |
| 13 | #include "SkRegion.h" |
| 14 | |
| 15 | class GrProcessorKeyBuilder; |
| 16 | |
| 17 | enum class GrStencilTest : uint16_t { |
| 18 | kAlways, |
| 19 | kNever, |
| 20 | kGreater, |
| 21 | kGEqual, |
| 22 | kLess, |
| 23 | kLEqual, |
| 24 | kEqual, |
| 25 | kNotEqual |
| 26 | }; |
| 27 | static constexpr int kGrStencilTestCount = 1 + (int)GrStencilTest::kNotEqual; |
| 28 | |
| 29 | enum class GrStencilOp : uint8_t { |
| 30 | kKeep, |
| 31 | kZero, |
| 32 | kReplace, // Replace stencil value with fRef (only the bits enabled in fWriteMask). |
| 33 | kInvert, |
| 34 | kIncWrap, |
| 35 | kDecWrap, |
| 36 | // NOTE: clamping occurs before the write mask. So if the MSB is zero and masked out, stencil |
| 37 | // values will still wrap when using clamping ops. |
| 38 | kIncClamp, |
| 39 | kDecClamp |
| 40 | }; |
| 41 | static constexpr int kGrStencilOpCount = 1 + (int)GrStencilOp::kDecClamp; |
| 42 | |
| 43 | /** |
| 44 | * This class defines concrete stencil settings that map directly to the underlying hardware. It |
| 45 | * is deduced from user stencil settings, stencil clip status, and the number of bits in the |
| 46 | * target stencil buffer. |
| 47 | */ |
| 48 | class GrStencilSettings { |
| 49 | public: |
| 50 | GrStencilSettings() { this->setDisabled(); } |
| 51 | GrStencilSettings(const GrUserStencilSettings& user, bool hasStencilClip, int numStencilBits) { |
| 52 | this->reset(user, hasStencilClip, numStencilBits); |
| 53 | } |
| 54 | GrStencilSettings(const GrStencilSettings& that) { this->reset(that); } |
| 55 | GrStencilSettings& operator=(const GrStencilSettings& that) { this->reset(that); return *this; } |
| 56 | |
| 57 | void invalidate() { fFlags |= kInvalid_PrivateFlag; } |
| 58 | void setDisabled() { fFlags = kAll_StencilFlags; } |
| 59 | void reset(const GrUserStencilSettings&, bool hasStencilClip, int numStencilBits); |
| 60 | void reset(const GrStencilSettings&); |
| 61 | |
| 62 | bool isValid() const { return !(fFlags & kInvalid_PrivateFlag); } |
| 63 | bool isDisabled() const { SkASSERT(this->isValid()); return fFlags & kDisabled_StencilFlag; } |
| 64 | bool doesWrite() const { SkASSERT(this->isValid()); |
| 65 | return !(fFlags & kNoModifyStencil_StencilFlag); } |
| 66 | bool isTwoSided() const { SkASSERT(this->isValid()); |
| 67 | return !(fFlags & kSingleSided_StencilFlag); } |
| 68 | bool usesWrapOp() const { SkASSERT(this->isValid()); |
| 69 | return !(fFlags & kNoWrapOps_StencilFlag); } |
| 70 | |
| 71 | void genKey(GrProcessorKeyBuilder* b) const; |
| 72 | |
| 73 | bool operator!=(const GrStencilSettings& that) const { return !(*this == that); } |
| 74 | bool operator==(const GrStencilSettings&) const; |
| 75 | |
| 76 | struct Face : public GrTStencilFaceSettings<GrStencilTest, GrStencilOp> { |
| 77 | void reset(const GrUserStencilSettings::Face&, bool useStencilClip, int numStencilBits); |
| 78 | void setDisabled(); |
| 79 | }; |
| 80 | |
| 81 | const Face& front() const { SkASSERT(!this->isDisabled()); return fFront; } |
| 82 | const Face& back() const { SkASSERT(this->isTwoSided()); return fBack; } |
| 83 | |
| 84 | /** |
| 85 | * Given a thing to draw into the stencil clip, a fill type, and a set op |
| 86 | * this function determines: |
| 87 | * 1. Whether the thing can be draw directly to the stencil clip or |
| 88 | * needs to be drawn to the client portion of the stencil first. |
| 89 | * 2. How many passes are needed. |
| 90 | * 3. What those passes are. |
| 91 | * |
| 92 | * @param op the set op to combine this element with the existing clip |
| 93 | * @param canBeDirect can the caller draw this element directly (without using stencil)? |
| 94 | * @param invertedFill is this path inverted |
| 95 | * @param drawDirectToClip out: true if caller should draw the element directly, false if it |
| 96 | * should draw it into the user stencil bits first. |
| 97 | * |
| 98 | * @return a null-terminated array of settings for stencil passes. |
| 99 | * |
| 100 | * If drawDirectToClip is false, the caller must first draw the element into the user |
| 101 | * stencil bits, and then cover the clip area with multiple passes using the returned |
| 102 | * stencil settings. |
| 103 | * |
| 104 | * If drawDirectToClip is true, the returned array will only have one pass and the |
| 105 | * caller should use those stencil settings while drawing the element directly. |
| 106 | */ |
| 107 | static GrUserStencilSettings const* const* GetClipPasses(SkRegion::Op op, |
| 108 | bool canBeDirect, |
| 109 | bool invertedFill, |
| 110 | bool* drawDirectToClip); |
| 111 | |
Mike Klein | 31550db | 2017-06-06 23:29:53 +0000 | [diff] [blame] | 112 | /** Gets the user stencil settings to directly set the clip bit. */ |
| 113 | static const GrUserStencilSettings* SetClipBitSettings(bool setToInside); |
| 114 | |
cdalton | 93a379b | 2016-05-11 13:58:08 -0700 | [diff] [blame] | 115 | private: |
| 116 | // Internal flag for backends to optionally mark their tracked stencil state as invalid. |
| 117 | enum { kInvalid_PrivateFlag = (kLast_StencilFlag << 1) }; |
| 118 | |
| 119 | uint32_t fFlags; |
| 120 | Face fFront; |
| 121 | Face fBack; |
| 122 | }; |
| 123 | |
| 124 | #endif |