/*  Starshatter: The Open Source Project
    Copyright (c) 2021-2024, Starshatter: The Open Source Project Contributors
    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
    Copyright (c) 1997-2006, Destroyer Studios LLC.

    AUTHOR:       John DiCamillo


    OVERVIEW
    ========
    Direct3D Texture Cache
*/

#include "TexDX9.h"
#include "VideoDX9.h"
#include "Bitmap.h"
#include "Color.h"
#include "Utils.h"

// +--------------------------------------------------------------------+

void  VideoDX9Error(const char* msg, HRESULT err);

#define TEXDX9_VERBOSE 0
#define DX9_TEXTURE_CACHE_SIZE 256

#ifndef RELEASE
#define RELEASE(x) if (x) { x->Release(); x=NULL; }
#endif

// +--------------------------------------------------------------------+

void
TexCacheDX9Entry::Release()
{
    RELEASE(texture);
}

// +--------------------------------------------------------------------+

void
TexCacheDX9Entry::Unload()
{
    RELEASE(texture);
    bitmap_id      = 0;
    used_last      = 0;
    last_modified  = 0;
}

// +--------------------------------------------------------------------+

TexCacheDX9::TexCacheDX9(VideoDX9* v)
: video(v), count(0), mru(0)
{
    d3d       = video->Direct3D();
    d3ddevice = video->D3DDevice();

    // clear the texture cache
    cache = new TexCacheDX9Entry[DX9_TEXTURE_CACHE_SIZE];
    vidmem = video->VidMemFree();
}

TexCacheDX9::~TexCacheDX9()
{
    int used = 0;

    if (cache) {
        for (int i = 0; i < DX9_TEXTURE_CACHE_SIZE; i++) {
            if (cache[i].bitmap_id)
            used++;
            cache[i].Unload();
        }

        delete [] cache;
        cache = 0;
    }

    Print("TexCacheDX9: final used count = %d\n", used);
}

// +--------------------------------------------------------------------+

bool
TexCacheDX9::LoadTexture(Bitmap* bmp, TexCacheDX9Entry* entry)
{
    if (!d3ddevice) return false;

    HRESULT hr = D3D_OK;

    // create the texture, if necessary
    if (!entry->texture || entry->bitmap_id != bmp->Handle()) {
        hr = d3ddevice->CreateTexture(bmp->Width(),
        bmp->Height(),
        1,                // one mip level
        0,                // no specific usage
        D3DFMT_A8R8G8B8,  // format matching Color::rgba
        D3DPOOL_MANAGED,
        &entry->texture,
        0);

        if (FAILED(hr) || !entry->texture) {
            VideoDX9Error("LoadTexture - could not create texture", hr);
            return false;
        }
    }

    // lock the surface for writing
    D3DLOCKED_RECT locked_rect;
    hr = entry->texture->LockRect(0, &locked_rect, 0, 0);

    if (FAILED(hr)) {
        VideoDX9Error("LoadTexture - could not lock texture surface", hr);
        entry->Unload();
        return false;
    }

    // load the bitmap into the texture surface
    for (int i = 0; i < bmp->Height(); i++) {
        BYTE* src = (BYTE*) (bmp->HiPixels()  + i * bmp->Width());
        BYTE* dst = (BYTE*) locked_rect.pBits + i * locked_rect.Pitch;

        CopyMemory(dst, src, bmp->Width() * sizeof(Color));
    }

    // unlock the surface
    entry->texture->UnlockRect(0);

    entry->last_modified = bmp->LastModified();
    vidmem = video->VidMemFree();
    return true;
}

// +--------------------------------------------------------------------+

void
TexCacheDX9::CreateNormalMap(int index, float amp)
{
    if (d3ddevice && cache[index].texture && !cache[index].normal) {
        HRESULT            hr    = D3D_OK;
        TexCacheDX9Entry*  entry = &cache[index];
        Bitmap*            bmp   = Bitmap::GetBitmapByID(entry->bitmap_id);

        IDirect3DTexture9* normal_map = 0;

        // create the normal map texture
        hr = d3ddevice->CreateTexture(bmp->Width(),
        bmp->Height(),
        1,                // one mip levels
        0,                // no specific usage
        D3DFMT_A8R8G8B8,  // format matching Color::rgba
        D3DPOOL_MANAGED,
        &normal_map,
        0);

        if (FAILED(hr) || !normal_map) {
            VideoDX9Error("CreateNormalMap - could not create texture", hr);
            return;
        }

        D3DXComputeNormalMap(normal_map, entry->texture ,NULL, 0, D3DX_CHANNEL_RED, amp);

        entry->texture->Release();
        entry->texture = normal_map;
        entry->normal  = true;

        // The D3DX function destroys the alpha channel data
        // when it builds the normal map.  We want the original
        // height data stored in the alpha channel, so we need
        // to add it back in now.

        // lock the surface for writing
        D3DLOCKED_RECT locked_rect;
        hr = normal_map->LockRect(0, &locked_rect, 0, 0);

        if (FAILED(hr)) {
            VideoDX9Error("CreateNormalMap - could not insert height channel", hr);
            return;
        }

        // load the bitmap into the texture surface
        for (int i = 0; i < bmp->Height(); i++) {
            BYTE* src = (BYTE*) (bmp->HiPixels()  + i * bmp->Width());
            BYTE* dst = (BYTE*) locked_rect.pBits + i * locked_rect.Pitch;

            src += 2; // red channel
            dst += 3; // alpha channel

            for (int n = 0; n < bmp->Width(); n++) {
                *dst = *src;

                dst += 4;
                src += 4;
            }
        }

        // unlock the surface
        normal_map->UnlockRect(0);
    }
}

// +--------------------------------------------------------------------+

IDirect3DTexture9*
TexCacheDX9::FindTexture(Bitmap* bmp)
{
    int avail = -1;

    if (!bmp)
    return 0;

    // check most recently used:
    if (cache[mru].bitmap_id == bmp->Handle()) {
        cache[mru].used_last = frame_number;

        // need to refresh?
        if (cache[mru].last_modified < bmp->LastModified()) {
            LoadTexture(bmp, &cache[mru]);
            cache[mru].normal = false;
        }

        return cache[mru].texture;
    }

    // find cache entry, or first free:
    for (int i = 0; i < DX9_TEXTURE_CACHE_SIZE; i++)
    if (cache[i].bitmap_id == bmp->Handle()) {
        cache[i].used_last = frame_number;
        mru = i;

        // need to refresh?
        if (cache[mru].last_modified < bmp->LastModified()) {
            LoadTexture(bmp, &cache[mru]);
            cache[mru].normal = false;
        }

        return cache[i].texture;
    }
    else if (avail < 0 && cache[i].bitmap_id == 0)
    avail = i;

    // no free space
    if (avail < 0)
    if (FreeUpCache())
    return FindTexture(bmp);
    else
    return 0;

    TexCacheDX9Entry* entry = &cache[avail];
    entry->bitmap_id = bmp->Handle();
    entry->used_last = frame_number;

    if (LoadTexture(bmp, entry)) {
#if TEXDX9_VERBOSE
        Print("   Tex %3d: id=%2d, size=%3d, type=%d, hTex=%3d, frame=%6d   vmf=%8d\n",
        avail, bmp->Handle(), bmp->Width(), bmp->Type(),
        cache[avail].texture, cache[avail].used_last, vidmem);
#endif
        mru = avail;
        cache[mru].normal = false;
        return entry->texture;
    }
    else {
        // failed to load texture,
        // erase cache entry:
        entry->Unload();
    }

    return 0;
}

// +--------------------------------------------------------------------+

IDirect3DTexture9*
TexCacheDX9::FindNormalMap(Bitmap* bmp, float amp)
{
    int avail = -1;

    if (!bmp)
    return 0;

    // check most recently used:
    if (cache[mru].bitmap_id == bmp->Handle()) {
        cache[mru].used_last = frame_number;

        // need to refresh?
        if (cache[mru].last_modified < bmp->LastModified()) {
            LoadTexture(bmp, &cache[mru]);
            cache[mru].normal = false;
        }

        if (!cache[mru].normal)
        CreateNormalMap(mru, amp);

        return cache[mru].texture;
    }

    // find cache entry, or first free:
    for (int i = 0; i < DX9_TEXTURE_CACHE_SIZE; i++)
    if (cache[i].bitmap_id == bmp->Handle()) {
        cache[i].used_last = frame_number;
        mru = i;

        // need to refresh?
        if (cache[i].last_modified < bmp->LastModified()) {
            LoadTexture(bmp, &cache[mru]);
            cache[i].normal = false;
        }

        if (!cache[i].normal)
        CreateNormalMap(i, amp);

        return cache[i].texture;
    }
    else if (avail < 0 && cache[i].bitmap_id == 0)
    avail = i;

    // no free space
    if (avail < 0)
    if (FreeUpCache())
    return FindTexture(bmp);
    else
    return 0;

    TexCacheDX9Entry* entry = &cache[avail];
    entry->bitmap_id = bmp->Handle();
    entry->used_last = frame_number;

    if (LoadTexture(bmp, entry)) {
#if TEXDX9_VERBOSE
        Print("   Tex %3d: id=%2d, size=%3d, type=%d, hTex=%3d, frame=%6d   vmf=%8d\n",
        avail, bmp->Handle(), bmp->Width(), bmp->Type(),
        cache[avail].texture, cache[avail].used_last, vidmem);
#endif
        mru = avail;
        CreateNormalMap(mru, amp);
        return entry->texture;
    }
    else {
        // failed to load texture,
        // erase cache entry:
        entry->Unload();
    }

    return 0;
}

// +--------------------------------------------------------------------+

int
TexCacheDX9::FreeLRU(int tries)
{
    int   unloaded = 0;

    while (tries--) {
        int   oldest   = -1;
        DWORD old      = frame_number;

        for (int i = 0; i < DX9_TEXTURE_CACHE_SIZE; i++) {
            DWORD ul = cache[i].used_last;

            if (ul && ul < old && ul != frame_number) {
                old = ul;
                oldest = i;
            }
        }

        if (oldest >= 0) {
            cache[oldest].Unload();
            unloaded++;
        }
        else
        break;
    }

    vidmem = video->VidMemFree();

#if TEXDX9_VERBOSE
    Print("   FreeLRU() frame=%6d unloaded=%2d vmf=%8d\n", frame_number, unloaded, vidmem);
#endif

    return unloaded;
}

// +--------------------------------------------------------------------+

int
TexCacheDX9::FreeUpCache()
{
    int unloaded = 0;

    for (int i = 0; i < DX9_TEXTURE_CACHE_SIZE; i++) {
        if (cache[i].used_last && cache[i].used_last < frame_number) {
            cache[i].Unload();
            unloaded++;
        }
    }

    vidmem = video->VidMemFree();

    Print("   FreeUpCache() frame=%6d unloaded=%2d vmf=%8d\n", frame_number, unloaded, vidmem);

    return unloaded;
}

// +--------------------------------------------------------------------+

void
TexCacheDX9::InvalidateCache()
{
    for (int i = 0; i < DX9_TEXTURE_CACHE_SIZE; i++) {
        cache[i].Unload();
        cache[i].normal = false;
    }

    vidmem = video->VidMemFree();
}