Brian Osman | f9aabff | 2018-11-13 16:11:38 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2010 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 | #ifndef GrVertexWriter_DEFINED |
| 9 | #define GrVertexWriter_DEFINED |
| 10 | |
Mike Klein | c0bd9f9 | 2019-04-23 12:05:21 -0500 | [diff] [blame] | 11 | #include "include/private/SkTemplates.h" |
Greg Daniel | f91aeb2 | 2019-06-18 09:58:02 -0400 | [diff] [blame] | 12 | #include "src/gpu/GrColor.h" |
Michael Ludwig | fd4f4df | 2019-05-29 09:51:09 -0400 | [diff] [blame] | 13 | #include "src/gpu/geometry/GrQuad.h" |
Brian Osman | f9aabff | 2018-11-13 16:11:38 -0500 | [diff] [blame] | 14 | #include <type_traits> |
| 15 | |
| 16 | /** |
| 17 | * Helper for writing vertex data to a buffer. Usage: |
| 18 | * GrVertexWriter vertices{target->makeVertexSpace(...)}; |
| 19 | * vertices.write(A0, B0, C0, ...); |
| 20 | * vertices.write(A1, B1, C1, ...); |
| 21 | * |
| 22 | * Supports any number of arguments. Each argument must be POD (plain old data), or an array |
| 23 | * thereof. |
| 24 | */ |
| 25 | struct GrVertexWriter { |
Brian Osman | 4486d98 | 2018-11-15 15:56:04 -0500 | [diff] [blame] | 26 | void* fPtr; |
| 27 | |
Brian Osman | cfec9d5 | 2018-11-20 11:39:15 -0500 | [diff] [blame] | 28 | template <typename T> |
| 29 | class Conditional { |
| 30 | public: |
| 31 | explicit Conditional(bool condition, const T& value) |
| 32 | : fCondition(condition), fValue(value) {} |
| 33 | private: |
| 34 | friend struct GrVertexWriter; |
| 35 | |
| 36 | bool fCondition; |
| 37 | T fValue; |
| 38 | }; |
| 39 | |
| 40 | template <typename T> |
| 41 | static Conditional<T> If(bool condition, const T& value) { |
| 42 | return Conditional<T>(condition, value); |
| 43 | } |
| 44 | |
Brian Osman | d2fa2eb | 2018-12-26 16:48:40 -0500 | [diff] [blame] | 45 | template <typename T> |
| 46 | struct Skip {}; |
| 47 | |
Brian Osman | f9aabff | 2018-11-13 16:11:38 -0500 | [diff] [blame] | 48 | template <typename T, typename... Args> |
| 49 | void write(const T& val, const Args&... remainder) { |
| 50 | static_assert(std::is_pod<T>::value, ""); |
Brian Osman | 0dd4302 | 2018-11-16 15:53:26 -0500 | [diff] [blame] | 51 | // This assert is barely related to what we're trying to check - that our vertex data |
| 52 | // matches our attribute layouts, where each attribute is aligned to four bytes. If this |
| 53 | // becomes a problem, just remove it. |
| 54 | static_assert(alignof(T) <= 4, ""); |
Brian Osman | f9aabff | 2018-11-13 16:11:38 -0500 | [diff] [blame] | 55 | memcpy(fPtr, &val, sizeof(T)); |
| 56 | fPtr = SkTAddOffset<void>(fPtr, sizeof(T)); |
| 57 | this->write(remainder...); |
| 58 | } |
| 59 | |
| 60 | template <typename T, size_t N, typename... Args> |
| 61 | void write(const T(&val)[N], const Args&... remainder) { |
| 62 | static_assert(std::is_pod<T>::value, ""); |
Brian Osman | 0dd4302 | 2018-11-16 15:53:26 -0500 | [diff] [blame] | 63 | static_assert(alignof(T) <= 4, ""); |
Brian Osman | f9aabff | 2018-11-13 16:11:38 -0500 | [diff] [blame] | 64 | memcpy(fPtr, val, N * sizeof(T)); |
| 65 | fPtr = SkTAddOffset<void>(fPtr, N * sizeof(T)); |
| 66 | this->write(remainder...); |
| 67 | } |
| 68 | |
Brian Osman | 5c8a6b3 | 2018-11-19 11:56:57 -0500 | [diff] [blame] | 69 | template <typename... Args> |
| 70 | void write(const GrVertexColor& color, const Args&... remainder) { |
| 71 | this->write(color.fColor[0]); |
| 72 | if (color.fWideColor) { |
| 73 | this->write(color.fColor[1]); |
| 74 | } |
| 75 | this->write(remainder...); |
| 76 | } |
| 77 | |
Brian Osman | cfec9d5 | 2018-11-20 11:39:15 -0500 | [diff] [blame] | 78 | template <typename T, typename... Args> |
| 79 | void write(const Conditional<T>& val, const Args&... remainder) { |
| 80 | if (val.fCondition) { |
| 81 | this->write(val.fValue); |
| 82 | } |
| 83 | this->write(remainder...); |
| 84 | } |
| 85 | |
Brian Osman | d2fa2eb | 2018-12-26 16:48:40 -0500 | [diff] [blame] | 86 | template <typename T, typename... Args> |
| 87 | void write(const Skip<T>& val, const Args&... remainder) { |
| 88 | fPtr = SkTAddOffset<void>(fPtr, sizeof(T)); |
| 89 | this->write(remainder...); |
| 90 | } |
| 91 | |
Michael Ludwig | f995c05 | 2018-11-26 15:24:29 -0500 | [diff] [blame] | 92 | template <typename... Args> |
| 93 | void write(const Sk4f& vector, const Args&... remainder) { |
| 94 | float buffer[4]; |
| 95 | vector.store(buffer); |
| 96 | this->write<float, 4>(buffer); |
| 97 | this->write(remainder...); |
| 98 | } |
| 99 | |
Brian Osman | f9aabff | 2018-11-13 16:11:38 -0500 | [diff] [blame] | 100 | void write() {} |
| 101 | |
Brian Osman | 4486d98 | 2018-11-15 15:56:04 -0500 | [diff] [blame] | 102 | /** |
| 103 | * Specialized utility for writing a four-vertices, with some data being replicated at each |
| 104 | * vertex, and other data being the appropriate 2-components from an SkRect to construct a |
| 105 | * triangle strip. |
| 106 | * |
| 107 | * writeQuad(A, B, C, ...) is similar to write(A, B, C, ...), except that: |
| 108 | * |
| 109 | * - Four sets of data will be written |
| 110 | * - For any arguments of type TriStrip, a unique SkPoint will be written at each vertex, |
| 111 | * in this order: left-top, left-bottom, right-top, right-bottom. |
| 112 | */ |
Brian Osman | 0dd4302 | 2018-11-16 15:53:26 -0500 | [diff] [blame] | 113 | template <typename T> |
| 114 | struct TriStrip { T l, t, r, b; }; |
| 115 | |
| 116 | static TriStrip<float> TriStripFromRect(const SkRect& r) { |
| 117 | return { r.fLeft, r.fTop, r.fRight, r.fBottom }; |
| 118 | } |
Brian Osman | 4486d98 | 2018-11-15 15:56:04 -0500 | [diff] [blame] | 119 | |
Brian Osman | cfec9d5 | 2018-11-20 11:39:15 -0500 | [diff] [blame] | 120 | template <typename T> |
| 121 | struct TriFan { T l, t, r, b; }; |
| 122 | |
| 123 | static TriFan<float> TriFanFromRect(const SkRect& r) { |
| 124 | return { r.fLeft, r.fTop, r.fRight, r.fBottom }; |
| 125 | } |
| 126 | |
Brian Osman | 4486d98 | 2018-11-15 15:56:04 -0500 | [diff] [blame] | 127 | template <typename... Args> |
| 128 | void writeQuad(const Args&... remainder) { |
| 129 | this->writeQuadVert<0>(remainder...); |
| 130 | this->writeQuadVert<1>(remainder...); |
| 131 | this->writeQuadVert<2>(remainder...); |
| 132 | this->writeQuadVert<3>(remainder...); |
| 133 | } |
| 134 | |
| 135 | private: |
| 136 | template <int corner, typename T, typename... Args> |
| 137 | void writeQuadVert(const T& val, const Args&... remainder) { |
| 138 | this->writeQuadValue<corner>(val); |
| 139 | this->writeQuadVert<corner>(remainder...); |
| 140 | } |
| 141 | |
| 142 | template <int corner> |
| 143 | void writeQuadVert() {} |
| 144 | |
| 145 | template <int corner, typename T> |
| 146 | void writeQuadValue(const T& val) { |
| 147 | this->write(val); |
| 148 | } |
| 149 | |
Brian Osman | 0dd4302 | 2018-11-16 15:53:26 -0500 | [diff] [blame] | 150 | template <int corner, typename T> |
| 151 | void writeQuadValue(const TriStrip<T>& r) { |
Brian Osman | 4486d98 | 2018-11-15 15:56:04 -0500 | [diff] [blame] | 152 | switch (corner) { |
Brian Osman | 0dd4302 | 2018-11-16 15:53:26 -0500 | [diff] [blame] | 153 | case 0: this->write(r.l, r.t); break; |
| 154 | case 1: this->write(r.l, r.b); break; |
| 155 | case 2: this->write(r.r, r.t); break; |
| 156 | case 3: this->write(r.r, r.b); break; |
Brian Osman | 4486d98 | 2018-11-15 15:56:04 -0500 | [diff] [blame] | 157 | } |
| 158 | } |
Brian Osman | 0dd4302 | 2018-11-16 15:53:26 -0500 | [diff] [blame] | 159 | |
Brian Osman | cfec9d5 | 2018-11-20 11:39:15 -0500 | [diff] [blame] | 160 | template <int corner, typename T> |
| 161 | void writeQuadValue(const TriFan<T>& r) { |
| 162 | switch (corner) { |
| 163 | case 0: this->write(r.l, r.t); break; |
| 164 | case 1: this->write(r.l, r.b); break; |
| 165 | case 2: this->write(r.r, r.b); break; |
| 166 | case 3: this->write(r.r, r.t); break; |
| 167 | } |
| 168 | } |
| 169 | |
Brian Osman | 0dd4302 | 2018-11-16 15:53:26 -0500 | [diff] [blame] | 170 | template <int corner> |
| 171 | void writeQuadValue(const GrQuad& q) { |
| 172 | this->write(q.point(corner)); |
| 173 | } |
Brian Osman | f9aabff | 2018-11-13 16:11:38 -0500 | [diff] [blame] | 174 | }; |
| 175 | |
| 176 | #endif |