C语言实现扫描填充算法填充三角形

好的，以下是C语言实现扫描填充算法填充三角形的代码：

#include <stdio.h>
#include <graphics.h>

void scanLineFill(int x1, int y1, int x2, int y2, int x3, int y3, int fill_color) {
    int i, j, x, y, tmp;
    float dx1, dx2, dx3, zx1, zx2, zx3;

    if (y1 > y2) {
        tmp = y1; y1 = y2; y2 = tmp;
        tmp = x1; x1 = x2; x2 = tmp;
    }
    if (y1 > y3) {
        tmp = y1; y1 = y3; y3 = tmp;
        tmp = x1; x1 = x3; x3 = tmp;
    }
    if (y2 > y3) {
        tmp = y2; y2 = y3; y3 = tmp;
        tmp = x2; x2 = x3; x3 = tmp;
    }

    dx1 = (float)(x2 - x1) / (float)(y2 - y1);
    dx2 = (float)(x3 - x1) / (float)(y3 - y1);
    dx3 = (float)(x3 - x2) / (float)(y3 - y2);

    zx1 = x1; zx2 = x1 + 0.5; zx3 = x2;

    for (i = y1; i <= y3; i++) {
        if (i < y2) {
            x = zx1; y = i;
            while (x <= zx3) {
                putpixel(x, y, fill_color);
                x++;
            }
        }
        else {
            x = zx2; y = i;
            while (x <= zx3) {
                putpixel(x, y, fill_color);
                x++;
            }
        }
        zx1 += dx1; zx2 += dx2; zx3 += dx3;
    }
}

int main() {
    int gd = DETECT, gm;
    initgraph(&gd, &gm, "");

    scanLineFill(100, 100, 200, 200, 100, 200, RED);

    getch();
    closegraph();
    return 0;
}

此代码基于扫描线算法实现，可以填充由三个点构成的任意三角形。