#include <stdio.h>
#include <gd.h>
#include <math.h>
void draw_japan_flag(gdImagePtr img);
void draw_red_sun(gdImagePtr img, int x, int y, int size, int color);
int main() {
int originalWidth = 1200;
int originalHeight = (int)(originalWidth * 2.0 / 3.0);
gdImagePtr img = gdImageCreateTrueColor(originalWidth, originalHeight);
gdImageAlphaBlending(img, 0);
draw_japan_flag(img);
// 新的宽度和高度以适应 "images" 文件夹
int newWidth = 600;
int newHeight = (int)(newWidth * 2.0 / 3.0);
// 创建新图像并进行缩放
gdImagePtr resizedImage = gdImageCreateTrueColor(newWidth, newHeight);
gdImageAlphaBlending(resizedImage, 0);
gdImageCopyResampled(resizedImage, img, 0, 0, 0, 0, newWidth, newHeight, originalWidth, originalHeight);
FILE *outputFile = fopen("./../images/japan_flag.png", "wb");
if (outputFile == NULL) {
fprintf(stderr, "Error opening the output file.\n");
return 1;
}
gdImagePng(resizedImage, outputFile);
fclose(outputFile);
gdImageDestroy(img);
gdImageDestroy(resizedImage);
return 0;
}
void draw_japan_flag(gdImagePtr img) {
int width = gdImageSX(img);
int height = gdImageSY(img);
// 创建一个白色背景
int white = gdImageColorAllocate(img, 255, 255, 255);
gdImageFilledRectangle(img, 0, 0, width - 1, height - 1, white);
// 绘制红色圆圈（太阳）
int red = gdImageColorAllocate(img, 255, 0, 0);
int center_x = width / 2;
int center_y = height / 2;
int radius = (int)((width * 2) / 3);
draw_red_sun(img, center_x, center_y, radius, red);
}
void draw_red_sun(gdImagePtr img, int x, int y, int size, int color) {
// 減小 size 的值,例如將他的值減半
size = size / 2;
gdImageArc(img, x, y, size, size, 0, 360, color);
gdImageFillToBorder(img, x, y, color, color);
}
