1 /*
2 * Copyright 2015-2017 ARM Limited
3 * SPDX-License-Identifier: Apache-2.0
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 #ifndef SPIRV_CROSS_SAMPLER_HPP
19 #define SPIRV_CROSS_SAMPLER_HPP
20
21 #include <vector>
22
23 namespace spirv_cross
24 {
25 struct spirv_cross_sampler_2d
26 {
~spirv_cross_sampler_2dspirv_cross::spirv_cross_sampler_2d27 inline virtual ~spirv_cross_sampler_2d()
28 {
29 }
30 };
31
32 template <typename T>
33 struct sampler2DBase : spirv_cross_sampler_2d
34 {
sampler2DBasespirv_cross::sampler2DBase35 sampler2DBase(const spirv_cross_sampler_info *info)
36 {
37 mips.insert(mips.end(), info->mipmaps, info->mipmaps + info->num_mipmaps);
38 format = info->format;
39 wrap_s = info->wrap_s;
40 wrap_t = info->wrap_t;
41 min_filter = info->min_filter;
42 mag_filter = info->mag_filter;
43 mip_filter = info->mip_filter;
44 }
45
samplespirv_cross::sampler2DBase46 inline virtual T sample(glm::vec2 uv, float bias)
47 {
48 return sampleLod(uv, bias);
49 }
50
sampleLodspirv_cross::sampler2DBase51 inline virtual T sampleLod(glm::vec2 uv, float lod)
52 {
53 if (mag_filter == SPIRV_CROSS_FILTER_NEAREST)
54 {
55 uv.x = wrap(uv.x, wrap_s, mips[0].width);
56 uv.y = wrap(uv.y, wrap_t, mips[0].height);
57 glm::vec2 uv_full = uv * glm::vec2(mips[0].width, mips[0].height);
58
59 int x = int(uv_full.x);
60 int y = int(uv_full.y);
61 return sample(x, y, 0);
62 }
63 else
64 {
65 return T(0, 0, 0, 1);
66 }
67 }
68
wrapspirv_cross::sampler2DBase69 inline float wrap(float v, spirv_cross_wrap wrap, unsigned size)
70 {
71 switch (wrap)
72 {
73 case SPIRV_CROSS_WRAP_REPEAT:
74 return v - glm::floor(v);
75 case SPIRV_CROSS_WRAP_CLAMP_TO_EDGE:
76 {
77 float half = 0.5f / size;
78 return glm::clamp(v, half, 1.0f - half);
79 }
80
81 default:
82 return 0.0f;
83 }
84 }
85
86 std::vector<spirv_cross_miplevel> mips;
87 spirv_cross_format format;
88 spirv_cross_wrap wrap_s;
89 spirv_cross_wrap wrap_t;
90 spirv_cross_filter min_filter;
91 spirv_cross_filter mag_filter;
92 spirv_cross_mipfilter mip_filter;
93 };
94
95 typedef sampler2DBase<glm::vec4> sampler2D;
96 typedef sampler2DBase<glm::ivec4> isampler2D;
97 typedef sampler2DBase<glm::uvec4> usampler2D;
98
99 template <typename T>
texture(const sampler2DBase<T> & samp,const glm::vec2 & uv,float bias=0.0f)100 inline T texture(const sampler2DBase<T> &samp, const glm::vec2 &uv, float bias = 0.0f)
101 {
102 return samp.sample(uv, bias);
103 }
104 }
105
106 #endif
107