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circle rendering, might change to make more efficient

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herbglitch 2023-06-25 02:22:50 -06:00
parent 57ff3302ad
commit 092908819d
4 changed files with 84 additions and 0 deletions
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src/graphics/sdl/circle.c Normal file
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#ifdef ARC_SDL
#include "arc/graphics/circle.h"
#include "arc/graphics/sdl/renderer.h"
#include <stdlib.h>
//Modified from https://stackoverflow.com/questions/38334081/how-to-draw-circles-arcs-and-vector-graphics-in-sdl
void ARC_Circle_Render(ARC_Circle *circle, ARC_Renderer *renderer, ARC_Color *color){
SDL_SetRenderDrawColor((SDL_Renderer *)renderer, color->r, color->g, color->b, color->a);
int32_t diameter = (circle->r * 2);
int32_t x = (circle->r - 1);
int32_t y = 0;
int32_t tx = 1;
int32_t ty = 1;
int32_t error = (tx - diameter);
while(x >= y){
// Each of the following renders an octant of the circle
SDL_RenderDrawPoint((SDL_Renderer *)renderer, circle->x + x, circle->y - y);
SDL_RenderDrawPoint((SDL_Renderer *)renderer, circle->x + x, circle->y + y);
SDL_RenderDrawPoint((SDL_Renderer *)renderer, circle->x - x, circle->y - y);
SDL_RenderDrawPoint((SDL_Renderer *)renderer, circle->x - x, circle->y + y);
SDL_RenderDrawPoint((SDL_Renderer *)renderer, circle->x + y, circle->y - x);
SDL_RenderDrawPoint((SDL_Renderer *)renderer, circle->x + y, circle->y + x);
SDL_RenderDrawPoint((SDL_Renderer *)renderer, circle->x - y, circle->y - x);
SDL_RenderDrawPoint((SDL_Renderer *)renderer, circle->x - y, circle->y + x);
if(error <= 0){
++y;
error += ty;
ty += 2;
}
if(error > 0){
--x;
tx += 2;
error += (tx - diameter);
}
}
}
#endif // ARC_SDL