Engine/ModuleShaderDescriptors.cpp at master · MeriAlguero/Engine · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
#include "Globals.h"
#include "ModuleShaderDescriptors.h"
#include "Application.h"
#include "ModuleD3D12.h"

bool ModuleShaderDescriptors::init()
{
    auto device = app->getD3D12()->getDevice();
    if (!device) {
        LOG("ERROR: ModuleShaderDescriptors::init: No D3D12 device!");
        return false;
    }

    // Create SRV heap
    D3D12_DESCRIPTOR_HEAP_DESC heapDesc = {};
    heapDesc.NumDescriptors = 256;  // Room for 256 textures
    heapDesc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV;
    heapDesc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE;

    HRESULT hr = device->CreateDescriptorHeap(&heapDesc, IID_PPV_ARGS(&m_srvHeap));
    if (FAILED(hr)) {
        LOG("ERROR: Failed to create SRV descriptor heap: 0x%08X", hr);
        return false;
    }

    m_srvDescriptorSize = device->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV);
    LOG("ModuleShaderDescriptors initialized: Heap size=%u, Descriptor size=%u",
        heapDesc.NumDescriptors, m_srvDescriptorSize);

    // ADDING NULL DESCRIPTOR AT INDEX 0
    CD3DX12_CPU_DESCRIPTOR_HANDLE cpuHandle(
        m_srvHeap->GetCPUDescriptorHandleForHeapStart(),
        0,
        m_srvDescriptorSize);

    // Create a null SRV descriptor
    D3D12_SHADER_RESOURCE_VIEW_DESC nullSrvDesc = {};
    nullSrvDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
    nullSrvDesc.ViewDimension = D3D12_SRV_DIMENSION_TEXTURE2D;
    nullSrvDesc.Shader4ComponentMapping = D3D12_DEFAULT_SHADER_4_COMPONENT_MAPPING;
    nullSrvDesc.Texture2D.MipLevels = 1;
    nullSrvDesc.Texture2D.MostDetailedMip = 0;

    device->CreateShaderResourceView(nullptr, &nullSrvDesc, cpuHandle);

    // Start next index at 1 since 0 is used for null descriptor
    m_nextIndex = 1;

    LOG("ModuleShaderDescriptors initialized with null descriptor at index 0");

    return true;
}

UINT ModuleShaderDescriptors::createSRV(ID3D12Resource* texture)
{
    if (!texture) return 0;

    auto device = app->getD3D12()->getDevice();
    UINT index = 0;

    // Reuse free indices if available
    if (!m_freeIndices.empty()) {
        index = m_freeIndices.back();
        m_freeIndices.pop_back();
    }
    else {
        index = m_nextIndex++;
    }

    // Create SRV
    D3D12_SHADER_RESOURCE_VIEW_DESC srvDesc = {};
    srvDesc.Shader4ComponentMapping = D3D12_DEFAULT_SHADER_4_COMPONENT_MAPPING;
    srvDesc.Format = texture->GetDesc().Format;
    srvDesc.ViewDimension = D3D12_SRV_DIMENSION_TEXTURE2D;
    srvDesc.Texture2D.MipLevels = 1;

    CD3DX12_CPU_DESCRIPTOR_HANDLE cpuHandle(
        m_srvHeap->GetCPUDescriptorHandleForHeapStart(),
        index,
        m_srvDescriptorSize);

    device->CreateShaderResourceView(texture, &srvDesc, cpuHandle);

    return index;
}

D3D12_GPU_DESCRIPTOR_HANDLE ModuleShaderDescriptors::getSRVGPUHandle(UINT index)
{
    if (index == 0) {
        // Return null handle
        D3D12_GPU_DESCRIPTOR_HANDLE nullHandle = { 0 };
        return nullHandle;
    }

    CD3DX12_GPU_DESCRIPTOR_HANDLE gpuHandle(
        m_srvHeap->GetGPUDescriptorHandleForHeapStart(),
        index,
        m_srvDescriptorSize);

    return gpuHandle;
}