Raylib中char转struct Texture方法及“int转struct Texture”编译报错求解

我是C语言新手，基于Raylib基础窗口示例编写代码时，一直出现编译错误：func.h:23: error: cannot cast 'int' to 'struct Texture'。调用renderTiles()时传入字符串作为tile参数，尝试在参数前添加char修饰后问题仍未解决，请问如何实现char到struct Texture的转换并解决该报错？

相关代码如下：

main.c #

/*
*   raylib [core] example - Basic window
*
*   Welcome to raylib!
*
*   To test examples, just press F6 and execute raylib_compile_execute script
*   Note that compiled executable is placed in the same folder as .c file
*
*   You can find all basic examples on C:\raylib\raylib\examples folder or
*   raylib official webpage: www.raylib.com
*
*   Enjoy using raylib. :)
*
*   Example originally created with raylib 1.0, last time updated with raylib 1.0

*   Example licensed under an unmodified zlib/libpng license, which is an OSI-certified,
*   BSD-like license that allows static linking with closed source software
*
*   Copyright (c) 2013-2022 Ramon Santamaria (@raysan5)
*
********************************************************************************************/

#include "raylib.h"
#include "func.h"

//------------------------------------------------------------------------------------
// Program main entry point
//------------------------------------------------------------------------------------
int main(void)
{
    // Initialization
    //--------------------------------------------------------------------------------------
    const int screenWidth = 768;
    const int screenHeight = 576;

    InitWindow(screenWidth, screenHeight, "raylib [core] example - basic window");

    SetTargetFPS(60);               // Set our game to run at 60 frames-per-second
    //--------------------------------------------------------------------------------------
    // textures
    Texture2D grass = LoadTexture("grass.png");
    Texture2D stone = LoadTexture("stone.png");
    Texture2D sand = LoadTexture("sand.png");
    Texture2D stone_oasis = LoadTexture("stone-oasis.png");
    Texture2D sand_oasis = LoadTexture("sand-oasis.png");
    Texture2D UI = LoadTexture("ui.png");
    
    // Main game loop
    while (!WindowShouldClose())    // Detect window close button or ESC key
    {
        // Update
        //----------------------------------------------------------------------------------
        // TODO: Update your variables here
        //----------------------------------------------------------------------------------

        // Draw
        //----------------------------------------------------------------------------------
        BeginDrawing();
            
            ClearBackground(RAYWHITE);
            DrawTexture(UI, 0, 0, RAYWHITE);
            renderTiles("grass");
            
        EndDrawing();
        //----------------------------------------------------------------------------------
    }

    // De-Initialization
    //--------------------------------------------------------------------------------------
    CloseWindow();        // Close window and OpenGL context
    //--------------------------------------------------------------------------------------
}

func.h #

#ifndef FUNC
#define FUNC

const int screenWidth = 768;
const int screenHeight = 576;

int centerX(int x)
{
    int ox = x + (screenWidth / 2);
    return (ox);
}

int centerY(int y)
{
   int oy = y + (screenHeight / 2);
   return(oy);
}
void renderTiles(tile)
{
   for( int b = 0; b < 12; b = b + 1)
      {
         for( int a = 0; a < 12; a = a + 1 ){
               DrawTexture(tile, (a * 48) + 96, (b * 48), RAYWHITE);

            }
      }
}

#endif

错误根源 #

1. renderTiles函数未声明参数类型，C语言会默认将无类型参数视为int，但你传入的是字符串字面量（const char*），后续DrawTexture需要的是Texture2D类型，直接导致类型不匹配报错。
2. 字符串是纹理的文件名标识，Texture2D是加载到内存的纹理对象，两者不能直接转换，你的思路从根源上有误。

修复步骤 #

1. 修正renderTiles的参数类型 #

直接把renderTiles的参数改成Texture2D类型，因为DrawTexture需要的就是这个类型：
修改func.h中的函数定义：

void renderTiles(Texture2D tile)
{
   for( int b = 0; b < 12; b = b + 1)
   {
      for( int a = 0; a < 12; a = a + 1 ){
            DrawTexture(tile, (a * 48) + 96, (b * 48), RAYWHITE);
      }
   }
}

2. 修改调用方式，传入已加载的纹理对象 #

在main.c的渲染部分，把renderTiles("grass")改成直接传入已经加载好的grass变量：

renderTiles(grass);

可选：通过字符串名称选择纹理 #

如果确实需要用字符串来指定要渲染的纹理，可以用字符串匹配实现（记得包含<string.h>头文件）：
在main.c中添加辅助函数：

#include <string.h>

Texture2D getTextureByName(const char* name) {
    if (strcmp(name, "grass") == 0) return grass;
    if (strcmp(name, "stone") == 0) return stone;
    if (strcmp(name, "sand") == 0) return sand;
    // 其他纹理的匹配逻辑
    return (Texture2D){0}; // 返回空纹理作为默认值
}

调用时：

renderTiles(getTextureByName("grass"));

额外修正：解决重复定义问题 #

func.h和main.c中都定义了screenWidth和screenHeight，会导致重复定义警告，建议只在一处定义：
在func.h中修改为外部声明：

extern const int screenWidth;
extern const int screenHeight;

保留main.c中的定义即可。

内容的提问来源于stack exchange，提问作者justtab