Skip to content

Instantly share code, notes, and snippets.

Embed
What would you like to do?
Drawing a normal and filled circle with SDL 2
#include <SDL.h>
SDL_Window* window;
SDL_Renderer* renderer;
void drawCircle(int xc, int yc, int x, int y) {
SDL_RenderDrawPoint(renderer, xc + x, yc + y);
SDL_RenderDrawPoint(renderer, xc - x, yc + y);
SDL_RenderDrawPoint(renderer, xc + x, yc - y);
SDL_RenderDrawPoint(renderer, xc - x, yc - y);
SDL_RenderDrawPoint(renderer, xc + y, yc + x);
SDL_RenderDrawPoint(renderer, xc - y, yc + x);
SDL_RenderDrawPoint(renderer, xc + y, yc - x);
SDL_RenderDrawPoint(renderer, xc - y, yc - x);
}
void fillCircle(int xc, int yc, int x, int y) {
SDL_RenderDrawLine(renderer, xc + x, yc + y, xc - x, yc + y);
SDL_RenderDrawLine(renderer, xc + x, yc - y, xc - x, yc - y);
SDL_RenderDrawLine(renderer, xc + y, yc + x, xc - y, yc + x);
SDL_RenderDrawLine(renderer, xc + y, yc - x, xc - y, yc - x);
}
void drawCircleBres(int xc, int yc, int r) {
int x = 0, y = r;
int d = 3 - 2 * r;
drawCircle(xc, yc, x, y);
while (y >= x) {
x++;
if (d > 0) {
y--;
d = d + 4 * (x - y) + 10;
} else
d = d + 4 * x + 6;
drawCircle(xc, yc, x, y);
}
}
void fillCircleBres(int xc, int yc, int r) {
int x = 0, y = r;
int d = 3 - 2 * r;
fillCircle(xc, yc, x, y);
while (y >= x) {
x++;
if (d > 0) {
y--;
d = d + 4 * (x - y) + 10;
} else
d = d + 4 * x + 6;
fillCircle(xc, yc, x, y);
}
}
int main() {
window = SDL_CreateWindow("test", SDL_WINDOWPOS_CENTERED,
SDL_WINDOWPOS_CENTERED, 300, 300, 0);
renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC);
while (!SDL_QuitRequested()) {
SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE);
SDL_RenderClear(renderer);
SDL_SetRenderDrawColor(renderer, 255, 255, 255, SDL_ALPHA_OPAQUE);
drawCircleBres(150, 150, 100);
SDL_SetRenderDrawColor(renderer, 0, 255, 255, SDL_ALPHA_OPAQUE);
fillCircleBres(150, 200, 100);
SDL_RenderPresent(renderer);
}
SDL_DestroyWindow(window);
return 0;
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.