c语言图形编辑器代码

实现一个图形编辑器需要的代码量比较大，这里提供一个简单的示例供参考，该示例使用了C语言和GTK+库实现。

#include <gtk/gtk.h>

static void destroy(GtkWidget *widget, gpointer data) {
    gtk_main_quit();
}

static gboolean delete_event(GtkWidget *widget, GdkEvent *event, gpointer data) {
    return FALSE;
}

static void draw_brush(GtkWidget *widget, gdouble x, gdouble y) {
    cairo_t *cr;
    GdkRectangle update_rect;

    /* 获取绘图区域的 cairo_t 对象 */
    cr = gdk_cairo_create(gtk_widget_get_window(widget));

    /* 设置线条样式 */
    cairo_set_line_width(cr, 10);
    cairo_set_line_cap(cr, CAIRO_LINE_CAP_ROUND);
    cairo_set_source_rgb(cr, 0, 0, 0);

    /* 绘制线条 */
    cairo_move_to(cr, x, y);
    cairo_line_to(cr, x, y);
    cairo_stroke(cr);

    /* 获取更新区域 */
    gdk_cairo_get_clip_rectangle(cr, &update_rect);

    /* 刷新绘图区域 */
    gtk_widget_queue_draw_area(widget, update_rect.x, update_rect.y, update_rect.width, update_rect.height);

    cairo_destroy(cr);
}

static gboolean button_press_event(GtkWidget *widget, GdkEventButton *event, gpointer data) {
    if (event->button == GDK_BUTTON_PRIMARY) {
        draw_brush(widget, event->x, event->y);
    }
    return TRUE;
}

static gboolean motion_notify_event(GtkWidget *widget, GdkEventMotion *event, gpointer data) {
    if (event->state & GDK_BUTTON1_MASK) {
        draw_brush(widget, event->x, event->y);
    }
    return TRUE;
}

int main(int argc, char *argv[]) {
    GtkWidget *window;
    GtkWidget *drawing_area;

    gtk_init(&argc, &argv);

    /* 创建主窗口 */
    window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title(GTK_WINDOW(window), "图形编辑器");
    gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);
    gtk_window_set_default_size(GTK_WINDOW(window), 800, 600);

    /* 创建绘图区域 */
    drawing_area = gtk_drawing_area_new();
    gtk_container_add(GTK_CONTAINER(window), drawing_area);

    /* 绑定事件处理函数 */
    g_signal_connect(G_OBJECT(window), "destroy", G_CALLBACK(destroy), NULL);
    g_signal_connect(G_OBJECT(window), "delete_event", G_CALLBACK(delete_event), NULL);
    g_signal_connect(G_OBJECT(drawing_area), "button_press_event", G_CALLBACK(button_press_event), NULL);
    g_signal_connect(G_OBJECT(drawing_area), "motion_notify_event", G_CALLBACK(motion_notify_event), NULL);

    /* 显示窗口 */
    gtk_widget_show_all(window);

    /* 进入事件循环 */
    gtk_main();

    return 0;
}

该示例中，使用GTK+库创建了一个主窗口和一个绘图区域，并绑定了鼠标事件处理函数。绘图区域的绘制使用了cairo库。具体实现可以参考GTK+和cairo库的文档。