SDL2 image class for 10 bitmaps from one surface

SDL Development
1

Hello, i try to make an class in Cand SDL2 to create 10 bmp like this: ■■■■■■■■■

But it dosnt work right now, it scale one time
Half up the screen ^^ whts wrong

#include <stdio.h>
#include <SDL2/SDL.h>

//this is what we need for the "array of" function,
#include <cstdlib> 
#include <sstream>   

#define bmp_hight 32
#define bmp_wight 32

const int MAX_BMP = 10;

class theBMP
{
 public:
 theBMP();
 
 bool isActive;
 
 SDL_Renderer* renderer;

 SDL_Surface* Bitmap2;
 SDL_Texture* texture2;
 const SDL_Rect * dstrect2;
 
 int bmp2_pos_x;
 int bmp2_pos_y;
 
 void show(SDL_Renderer *renderer, SDL_Texture *texture2, const  SDL_Rect * dstrect2);
 
 private: 
 };
 theBMP arrayofBMP[MAX_BMP];

//_______________________

theBMP::theBMP()
{
 bmp2_pos_x;
 bmp2_pos_y;	
}

//_______________________

void theBMP::show (SDL_Renderer *renderer, 
									 SDL_Texture *texture2, 
									 const SDL_Rect * dstrect2)
{

 //now we clone 10x the Position and the bmp 
 for (int i =0; i<MAX_BMP; i++)
 {
  if (arrayofBMP[i].isActive == true)
  {
     SDL_Rect dstrect;

     dstrect.x = arrayofBMP[i]. bmp2_pos_x;
     dstrect.y = arrayofBMP[i]. bmp2_pos_y;

    //draw bitmap2
    SDL_RenderCopy(renderer, texture2, NULL, &dstrect); 
  }
 }	

}

//_______________________

int main(int argc, char *argv[])
{

  SDL_Event event;
	
	if (SDL_Init(SDL_INIT_EVERYTHING) != 0)
	{
		fprintf(stderr, "SDL_Init Error: %s\n", SDL_GetError());
		return 1;
	}

//create Window 
 SDL_Window *window = SDL_CreateWindow("Test", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, 0);

//create renderer
 SDL_Renderer *renderer =   
 SDL_CreateRenderer(window, -1, 0);

 //create Surface and load Bitmap (background)
 SDL_Surface *Bitmap1 =  
 SDL_LoadBMP("background.bmp");
  
 //create texture from Surface 
 SDL_Texture *texture1 = SDL_CreateTextureFromSurface(renderer, Bitmap1);

//_____________

 //create Surface2 and load Bitmap2 (for the Class)
 SDL_Surface *Bitmap2 =  
 SDL_LoadBMP("bitmap2.bmp");
 
//create texture2 from Surface2  
 SDL_Texture *texture2 = SDL_CreateTextureFromSurface(renderer, Bitmap2);

 //load the class  
  theBMP myClass;
  
  // this is the position for the class
     SDL_Rect dstrect3 = {0,0,10,10};
     
//_____________
  
 //GAME LOOP
 bool quit = false;
 int game_var =2;
 
 while (!quit)
 {	
   SDL_WaitEvent(&event);
	
  //back button on android || x on pc window
	switch (event.type)
	{
     case SDL_QUIT:
	 quit = true;
	 break;
	}

   //draw Bitmap "background"    on x, y, size  on screebän  
   SDL_Rect dstrect1= { 0, 0, 2340, 1028 };
   
   SDL_RenderCopy(renderer, texture1, NULL, &dstrect1);

//_____________

  if(game_var == 2)
  {
    for (int i =0; i<MAX_BMP; i++)
    {
     arrayofBMP[i]. bmp2_pos_x = 100;
     arrayofBMP[i]. bmp2_pos_y =500;     //original class position
     arrayofBMP[i].isActive = true;
    }
    game_var =1;
   }
   
  for (int i =0; i<MAX_BMP; i++)
 {
  if (arrayofBMP[i].isActive == true)
  {
     dstrect3.x = arrayofBMP[i]. bmp2_pos_x +64;
     dstrect3.y = arrayofBMP[i]. bmp2_pos_y;

    SDL_RenderCopy(renderer, texture2, NULL, &dstrect3); 
  }
 }
   myClass.show(renderer,texture2, &dstrect3);
  	
//_____________
   
   //draw renderer
   SDL_RenderPresent(renderer);	
  } 
  //END GAME LOOP
	
//------------------------
	
 SDL_DestroyTexture(texture1);
 SDL_FreeSurface(Bitmap1);
	
 SDL_DestroyTexture(texture2);
 SDL_FreeSurface(Bitmap2);

 SDL_DestroyRenderer(renderer);
 SDL_DestroyWindow(window);

  SDL_Quit();
  return 0;
}

Screenshot_20240717_233137_SDL plugin for C4droid
Screenshot_20240717_233137_SDL plugin for C4droid1920×861 175 KB

2

The theBMP constructor doesn’t do anything (it doesn’t initialize any of the member variables).

The member variables renderer, Bitmap2, texture2 and dstrect2 are never used.

The show member function doesn’t use the object that it’s called on so it could be a static member function or not part of the class at all. If you do that change you’ll no longer need the myClass variable.

Since all members are public, and the constructor doesn’t actually do anything, you might want to consider simply making it a “struct”.

struct theBMP
{
	bool isActive;
	int bmp2_pos_x;
	int bmp2_pos_y;
};

The function parameter dstrect2 is never used inside the show function.

dstrect.w and dstrect.h are never initialized.

All elements in arrayofBMP have the same positions so you end up drawing texture2 multiple times on top of each other. Since you do this at two places in the code with different offsets you might see it at two different locations.