// Copyright 2017 The Dawn Authors
//
// 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 COMMON_CONSTANTS_H_
#define COMMON_CONSTANTS_H_

#include <cstdint>

static constexpr uint32_t kMaxBindGroups = 4u;
static constexpr uint8_t kMaxVertexAttributes = 16u;
// Vulkan has a standalone limit named maxVertexInputAttributeOffset (2047u at least) for vertex
// attribute offset. The limit might be meaningless because Vulkan has another limit named
// maxVertexInputBindingStride (2048u at least). We use maxVertexAttributeEnd (2048u) here to
// verify vertex attribute offset, which equals to maxOffset + smallest size of vertex format
// (char). We may use maxVertexInputBindingStride (maxVertexBufferStride below) instead to replace
// maxVertexAttributeEnd in future.
static constexpr uint32_t kMaxVertexAttributeEnd = 2048u;
static constexpr uint8_t kMaxVertexBuffers = 16u;
static constexpr uint32_t kMaxVertexBufferStride = 2048u;
static constexpr uint32_t kNumStages = 3;
static constexpr uint8_t kMaxColorAttachments = 4u;
static constexpr uint32_t kTextureBytesPerRowAlignment = 256u;
// Dynamic buffer offsets require offset to be divisible by 256
static constexpr uint64_t kMinDynamicBufferOffsetAlignment = 256u;

// Per stage limits
static constexpr uint32_t kMaxSampledTexturesPerShaderStage = 16;
static constexpr uint32_t kMaxSamplersPerShaderStage = 16;
static constexpr uint32_t kMaxStorageBuffersPerShaderStage = 6;
static constexpr uint32_t kMaxStorageTexturesPerShaderStage = 4;
static constexpr uint32_t kMaxUniformBuffersPerShaderStage = 12;

// Per pipeline layout limits
static constexpr uint32_t kMaxDynamicUniformBuffersPerPipelineLayout = 8u;
static constexpr uint32_t kMaxDynamicStorageBuffersPerPipelineLayout = 4u;

// Max size of uniform buffer binding
static constexpr uint64_t kMaxUniformBufferBindingSize = 16384u;

// Indirect command sizes
static constexpr uint64_t kDispatchIndirectSize = 3 * sizeof(uint32_t);
static constexpr uint64_t kDrawIndirectSize = 4 * sizeof(uint32_t);
static constexpr uint64_t kDrawIndexedIndirectSize = 5 * sizeof(uint32_t);

// Non spec defined constants.
static constexpr float kLodMin = 0.0;
static constexpr float kLodMax = 1000.0;

// Max texture size constants
static constexpr uint32_t kMaxTextureSize = 8192u;
static constexpr uint32_t kMaxTexture2DArrayLayers = 256u;
static constexpr uint32_t kMaxTexture2DMipLevels = 14u;
static_assert(1 << (kMaxTexture2DMipLevels - 1) == kMaxTextureSize,
              "kMaxTexture2DMipLevels and kMaxTextureSize size mismatch");

// Offset alignment for CopyB2B. Strictly speaking this alignment is required only
// on macOS, but we decide to do it on all platforms.
static constexpr uint64_t kCopyBufferToBufferOffsetAlignment = 4u;

#endif  // COMMON_CONSTANTS_H_