将数组指针访问从C++转换为Delphi

Translating array pointer access from C++ to Delphi

本文关键字：转换 Delphi C++ 数组 指针 访问      更新时间：2023-10-16

我想知道我是否正确地将一段代码从C++翻译成了Delphi。它看起来很有效，但我有一种感觉，我在读和写记忆，我不应该使用Delphi。

给定C++代码：

struct tile_map
{
    int32 CountX;
    int32 CountY;
    uint32 *Tiles;
};
inline uint32
GetTileValueUnchecked(tile_map *TileMap, int32 TileX, int32 TileY)
{
    uint32 TileMapValue = TileMap->Tiles[TileY*TileMap->CountX + TileX];
    return(TileMapValue);
}
uint32 Tiles00[9][17] =
    {
        {1, 1, 1, 1,  1, 1, 1, 1,  0, 1, 1, 1,  1, 1, 1, 1, 1},
        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1},
        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1},
        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1},
        {0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1},
        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1},
        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1},
        {1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1},
        {1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, 1},
    };
// More tile map declarations ...   
// uint32 Tiles01[9][17] = ...
// uint32 Tiles10[9][17] = ...
// uint32 Tiles11[9][17] = ...  
    tile_map TileMaps[2][2];
    TileMaps[0][0].CountX = 17;
    TileMaps[0][0].CountY = 9;
    TileMaps[0][0].Tiles = (uint32 *)Tiles00;
    TileMaps[0][1] = TileMaps[0][0];
    TileMaps[0][1].Tiles = (uint32 *)Tiles01;
    TileMaps[1][0] = TileMaps[0][0];
    TileMaps[1][0].Tiles = (uint32 *)Tiles10;
    TileMaps[1][1] = TileMaps[0][0];
    TileMaps[1][1].Tiles = (uint32 *)Tiles11;
// Usage
    int32 PlayerTileX = 2;
    int32 PlayerTileY = 2;
    uint32 TileMapValue = GetTileValueUnchecked(&TileMap[1][1], PlayerTileX, PlayerTileY);

Delphi翻译：

program Project1;
{$APPTYPE CONSOLE}
type
    Puint32 = ^uint32;
    tile_map = record
        CountX : int32;
        CountY : int32;
        Tiles : Puint32;
    end;
    Ptile_map = ^tile_map;
{$POINTERMATH ON}   
function GetTileValueUnchecked(TileMap : Ptile_map; TileX, TileY : int32) : uint32; inline;
begin
    result := TileMap^.Tiles[TileY * TileMap^.CountX + TileX];
end;

const //in the future these will be read from file, so const for now
    Tiles00:  array [0..8, 0..16] of uint32 =
    (
        (1, 1, 1, 1,  1, 1, 1, 1,  0, 1, 1, 1,  1, 1, 1, 1, 1),
        (1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1),
        (1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1),
        (1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1),
        (0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1),
        (1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1),
        (1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1),
        (1, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0,  0, 0, 0, 0, 1),
        (1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1,  1, 1, 1, 1, 1)
    );
    // More tile map declarations ...
    //Tiles01:  array [0..8, 0..16] of uint32 = ...
    //Tiles10:  array [0..8, 0..16] of uint32 = ...
    //Tiles11:  array [0..8, 0..16] of uint32 = ...
var 
    TileMaps : array [0..1, 0..1] of  tile_map;
    PlayerTileX, PlayerTileY : int32;
    TileMapValue : uint32;
begin
    TileMaps[0][0].CountX := 17;
    TileMaps[0][0].CountY := 9;
    TileMaps[0][0].Tiles := Addr(Tiles00);
    TileMaps[0][1] := TileMaps[0][0];
    TileMaps[0][1].Tiles := Addr(Tiles01);
    TileMaps[1][0] := TileMaps[0][0];
    TileMaps[1][0].Tiles := Addr(Tiles10);
    TileMaps[1][1] := TileMaps[0][0];
    TileMaps[1][1].Tiles := Addr(Tiles11);
    // Usage
    PlayerTileX := 2;
    PlayerTileY := 2;
    TileMapValue = GetTileValueUnchecked(@TileMaps[1][1], PlayerTileX, PlayerTileY);
end.

David Heffernan的评论很有帮助，其他人似乎也同意代码是正确的，所以我将把它标记为已回答。

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