blob: 02c6ecc27e490d9289ec271a472a3505dc317bc9 [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 "GrMtlSampler.h"
#include "GrMtlGpu.h"
static inline MTLSamplerAddressMode wrap_mode_to_mtl_sampler_address(
GrSamplerState::WrapMode wrapMode) {
switch (wrapMode) {
case GrSamplerState::WrapMode::kClamp:
return MTLSamplerAddressModeClampToEdge;
case GrSamplerState::WrapMode::kRepeat:
return MTLSamplerAddressModeRepeat;
case GrSamplerState::WrapMode::kMirrorRepeat:
return MTLSamplerAddressModeMirrorRepeat;
}
SK_ABORT("Unknown wrap mode.");
return MTLSamplerAddressModeClampToEdge;
}
GrMtlSampler* GrMtlSampler::Create(const GrMtlGpu* gpu, const GrSamplerState& samplerState,
uint32_t maxMipLevel) {
static MTLSamplerMinMagFilter mtlMinMagFilterModes[] = {
MTLSamplerMinMagFilterNearest,
MTLSamplerMinMagFilterLinear,
MTLSamplerMinMagFilterLinear
};
GR_STATIC_ASSERT((int)GrSamplerState::Filter::kNearest == 0);
GR_STATIC_ASSERT((int)GrSamplerState::Filter::kBilerp == 1);
GR_STATIC_ASSERT((int)GrSamplerState::Filter::kMipMap == 2);
auto samplerDesc = [[MTLSamplerDescriptor alloc] init];
samplerDesc.rAddressMode = MTLSamplerAddressModeClampToEdge;
samplerDesc.sAddressMode = wrap_mode_to_mtl_sampler_address(samplerState.wrapModeX());
samplerDesc.tAddressMode = wrap_mode_to_mtl_sampler_address(samplerState.wrapModeY());
samplerDesc.magFilter = mtlMinMagFilterModes[static_cast<int>(samplerState.filter())];
samplerDesc.minFilter = mtlMinMagFilterModes[static_cast<int>(samplerState.filter())];
samplerDesc.mipFilter = MTLSamplerMipFilterLinear;
samplerDesc.lodMinClamp = 0.0f;
bool useMipMaps = GrSamplerState::Filter::kMipMap == samplerState.filter() && maxMipLevel > 0;
samplerDesc.lodMaxClamp = !useMipMaps ? 0.0f : (float)(maxMipLevel);
samplerDesc.maxAnisotropy = 1.0f;
samplerDesc.normalizedCoordinates = true;
samplerDesc.compareFunction = MTLCompareFunctionNever;
return new GrMtlSampler([gpu->device() newSamplerStateWithDescriptor: samplerDesc]);
}