How can I "freeze" a rendered table? - c++

Question

I have a table that I render like this:
void startRender() {
this->x = 0;
this->y = this->bord_y;
constr_list(coords);
SDL_SetRenderDrawColor( this->rend, 0x00, 0x00, 0x00, 0xFF );
for (int i = 0; i < this->cellsInColumn; i++) {
for (int j = 0; j < this->cellsInRow; j++) {
SDL_Rect outlineRect = { this->x + this->bord_x + (cellWidth*j), this->y+this->bord_y+(cellHeight*i), this->cellWidth, this->cellHeight };
SDL_RenderDrawRect( this->rend, &outlineRect );
comp_in(coords, (this->x + this->bord_x + (cellWidth*j)), (this->y+this->bord_y+(cellHeight*i)));
}
}
}
I save the coordinates in a handwritten list for further processing. Furthermore, I tried to display the table in the same place where it was drawn using known coordinates.
void onlyRender() {
comp* c = coords.head;
this->x = c->coordX;
this->y = c->coordY;
SDL_SetRenderDrawColor( this->rend, 0x00, 0x00, 0x00, 0xFF );
for (int i = 0; i < this->cellsInColumn; i++) {
for (int j = 0; j < this->cellsInRow; j++) {
SDL_Rect outlineRect = { this->x, this->y, this->cellWidth, this->cellHeight };
SDL_RenderDrawRect( this->rend, &outlineRect );
if(c->next != NULL) { c = c->next; }
else{ break; }
this->x = c->coordX;
}
this->y = c->coordY;
}
}
But the table is displayed below.
Question: Can I make the table always appear in the same place? If so, how?

Answer 1

The root of the problem has been found. If anyone is really interested, here was what happened.
Referring to this question of mine, when I couldn't draw the grid properly, I missed a very important point. I'm drawing the grid OUTSIDE the main program loop. Here is the code for the current main function:
int main( int argc, char* args[] ) {
Manager* mainMan = new Manager(1360, 768, 30, 5);
auto win = mainMan->getWindow();
mainMan->start();
if( !win.init() )
{
cout << "Failed to initialize!" << endl;
}
else
{
//Main loop flag
bool quit = false;
//Event handler
SDL_Event e;
//While application is running
while( !quit ) {
mainMan->moveBeam();
//Handle events on queue
while( SDL_PollEvent( &e ) != 0 ) {
//User requests quit
if( e.type == SDL_QUIT )
{
quit = true;
}
else if (e.type == SDL_KEYDOWN) {
win.handleKeys( e.key );
}
}
}
}
//Free resources and close SDL
win.close();
return 0;
}
Function mainMan->start() draws a grid before the main logic of the program. At this point, for some reason, the image is rendered under the "decoration" or under the title bar. It looks like this:
But when the program reaches the main loop while( !quit ) everything changes. Now the program considers the first pixel of the window like the (0,0) coordinate, and not some pixel under the title bar. It looks like this:
Maybe somewhere it was said about this feature of the work, but in any case, I found it myself by trial and error. Thank you all for your attention!