// Copyright (c) 2008-2023 the Urho3D project
// License: MIT

#include "../../Precompiled.h"

#include "../../Graphics/Graphics.h"
#include "D3D11GraphicsImpl.h"

#include "../../DebugNew.h"

namespace Urho3D
{

GraphicsImpl_D3D11::GraphicsImpl_D3D11() :
    device_(nullptr),
    deviceContext_(nullptr),
    swapChain_(nullptr),
    defaultRenderTargetView_(nullptr),
    defaultDepthTexture_(nullptr),
    defaultDepthStencilView_(nullptr),
    depthStencilView_(nullptr),
    resolveTexture_(nullptr),
    shaderProgram_(nullptr)
{
    for (unsigned i = 0; i < MAX_RENDERTARGETS; ++i)
        renderTargetViews_[i] = nullptr;

    for (unsigned i = 0; i < MAX_TEXTURE_UNITS; ++i)
    {
        shaderResourceViews_[i] = nullptr;
        samplers_[i] = nullptr;
    }

    for (unsigned i = 0; i < MAX_VERTEX_STREAMS; ++i)
    {
        vertexBuffers_[i] = nullptr;
        vertexSizes_[i] = 0;
        vertexOffsets_[i] = 0;
    }

    for (unsigned i = 0; i < MAX_SHADER_PARAMETER_GROUPS; ++i)
    {
        constantBuffers_[VS][i] = nullptr;
        constantBuffers_[PS][i] = nullptr;
    }
}

bool GraphicsImpl_D3D11::CheckMultiSampleSupport(DXGI_FORMAT format, unsigned sampleCount) const
{
    if (sampleCount < 2)
        return true; // Not multisampled

    UINT numLevels = 0;
    if (FAILED(device_->CheckMultisampleQualityLevels(format, sampleCount, &numLevels)))
        return false;
    else
        return numLevels > 0;
}

unsigned GraphicsImpl_D3D11::GetMultiSampleQuality(DXGI_FORMAT format, unsigned sampleCount) const
{
    if (sampleCount < 2)
        return 0; // Not multisampled, should use quality 0

    if (device_->GetFeatureLevel() >= D3D_FEATURE_LEVEL_10_1)
        return 0xffffffff; // D3D10.1+ standard level

    UINT numLevels = 0;
    if (FAILED(device_->CheckMultisampleQualityLevels(format, sampleCount, &numLevels)) || !numLevels)
        return 0; // Errored or sample count not supported
    else
        return numLevels - 1; // D3D10.0 and below: use the best quality
}

}