c++ - SDL2 render texture visibly lags behind mouse -


i'm using sdl2 on windows (i've tested both windows 7 , windows 8). playing around rendering texture locked mouse coordinates create sort of "crosshair" effect.

it works, texture visibly lags behind mouse creates awkward delay between mouse motion , rendered updates. honestly, delay minor, cares absolute accuracy, drive person insane.

my question basically, normal? i'm guessing delay due time takes windows deliver event sdl , sdl deliver event me. how can 1 achieve locked "crosshair" effect via sdl?

my code reference:

#include "sdl.h"  int main( int argc, char* args[] )  {      sdl_init( sdl_init_everything );       sdl_window* window = sdl_createwindow("sdl", 100, 100, 640, 480, sdl_window_shown);      sdl_renderer* renderer = sdl_createrenderer(window, -1, sdl_renderer_accelerated);      sdl_surface* surface = sdl_loadbmp("mouse.bmp");      sdl_texture* texture = sdl_createtexturefromsurface(renderer, surface);     sdl_freesurface(surface);      bool isexiting = false;     int x = 0;     int y = 0;      while(!isexiting)     {         sdl_event e;         while(sdl_pollevent(&e))         {             if(e.type == sdl_quit)             {                 isexiting = true;                 break;             }             else if(e.type == sdl_mousemotion)             {                 x = e.motion.x;                 y = e.motion.y;             }         }          sdl_rect destrect;         destrect.h = 19;         destrect.w = 19;         destrect.x = x;         destrect.y = y;          sdl_renderclear(renderer);         sdl_rendercopy(renderer, texture, null, &destrect);         sdl_renderpresent(renderer);     }      sdl_quit();       return 0;  }

while cannot sure why loop lags, sdl has support changing mouse surface, other functions may interested in. seems put sdl_createcolorcursor(sdl_surface* surface, int hot_x, int hot_y) use. here's link wiki page on mouse support: http://wiki.libsdl.org/categorymouse

happy coding!


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