SPIRV-Cross/include/spirv_cross/sampler.hpp
2020-03-10 10:52:27 +01:00

106 lines
2.4 KiB
C++

/*
* Copyright 2015-2017 ARM Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SPIRV_CROSS_SAMPLER_HPP
#define SPIRV_CROSS_SAMPLER_HPP
#include <vector>
namespace spirv_cross
{
struct spirv_cross_sampler_2d
{
inline virtual ~spirv_cross_sampler_2d()
{
}
};
template <typename T>
struct sampler2DBase : spirv_cross_sampler_2d
{
sampler2DBase(const spirv_cross_sampler_info *info)
{
mips.insert(mips.end(), info->mipmaps, info->mipmaps + info->num_mipmaps);
format = info->format;
wrap_s = info->wrap_s;
wrap_t = info->wrap_t;
min_filter = info->min_filter;
mag_filter = info->mag_filter;
mip_filter = info->mip_filter;
}
inline virtual T sample(glm::vec2 uv, float bias)
{
return sampleLod(uv, bias);
}
inline virtual T sampleLod(glm::vec2 uv, float lod)
{
if (mag_filter == SPIRV_CROSS_FILTER_NEAREST)
{
uv.x = wrap(uv.x, wrap_s, mips[0].width);
uv.y = wrap(uv.y, wrap_t, mips[0].height);
glm::vec2 uv_full = uv * glm::vec2(mips[0].width, mips[0].height);
int x = int(uv_full.x);
int y = int(uv_full.y);
return sample(x, y, 0);
}
else
{
return T(0, 0, 0, 1);
}
}
inline float wrap(float v, spirv_cross_wrap wrap, unsigned size)
{
switch (wrap)
{
case SPIRV_CROSS_WRAP_REPEAT:
return v - glm::floor(v);
case SPIRV_CROSS_WRAP_CLAMP_TO_EDGE:
{
float half = 0.5f / size;
return glm::clamp(v, half, 1.0f - half);
}
default:
return 0.0f;
}
}
std::vector<spirv_cross_miplevel> mips;
spirv_cross_format format;
spirv_cross_wrap wrap_s;
spirv_cross_wrap wrap_t;
spirv_cross_filter min_filter;
spirv_cross_filter mag_filter;
spirv_cross_mipfilter mip_filter;
};
typedef sampler2DBase<glm::vec4> sampler2D;
typedef sampler2DBase<glm::ivec4> isampler2D;
typedef sampler2DBase<glm::uvec4> usampler2D;
template <typename T>
inline T texture(const sampler2DBase<T> &samp, const glm::vec2 &uv, float bias = 0.0f)
{
return samp.sample(uv, bias);
}
}
#endif