C 我需要知道最简单的方法来绘制一个形状在gtk与开罗
有人能告诉我在C 我需要知道最简单的方法来绘制一个形状在gtk与开罗,c,gtk3,cairo,C,Gtk3,Cairo,有人能告诉我在gtk中画矩形的最简单方法吗?请简单。这是一个挑战。编写一个文件,尽可能用几行代码绘制任何cairo形状。我在网上找到了工作图代码,但它非常复杂,并非所有这些都是必需的。有人能给我写一些代码,用几行代码画出任何cairo形状,这样我就可以把它作为我游戏的参考了吗 这里有一些工作代码,但非常复杂。我不需要在鼠标点击时画矩形,只要从四个数字中画一个矩形。有人,请减少到什么是绝对必要的画一个矩形。最好我想画一个没有任何其他函数的矩形,除了主函数(一旦主函数返回零,一切结束) 守则: #i
gtk
中画矩形的最简单方法吗?请简单。这是一个挑战。编写一个文件,尽可能用几行代码绘制任何cairo
形状。我在网上找到了工作图代码,但它非常复杂,并非所有这些都是必需的。有人能给我写一些代码,用几行代码画出任何cairo
形状,这样我就可以把它作为我游戏的参考了吗
这里有一些工作代码,但非常复杂。我不需要在鼠标点击时画矩形,只要从四个数字中画一个矩形。有人,请减少到什么是绝对必要的画一个矩形。最好我想画一个没有任何其他函数的矩形,除了主函数(一旦主函数返回零,一切结束)
守则:
#include <gtk/gtk.h>
/* Surface to store current scribbles */
static cairo_surface_t *surface = NULL;
static void
clear_surface (void)
{
cairo_t *cr;
cr = cairo_create (surface);
cairo_set_source_rgb (cr, 1, 1, 1);
cairo_paint (cr);
cairo_destroy (cr);
}
/* Create a new surface of the appropriate size to store our scribbles */
static gboolean
configure_event_cb (GtkWidget *widget,
GdkEventConfigure *event,
gpointer data)
{
if (surface)
cairo_surface_destroy (surface);
surface = gdk_window_create_similar_surface (gtk_widget_get_window (widget),
CAIRO_CONTENT_COLOR,
gtk_widget_get_allocated_width (widget),
gtk_widget_get_allocated_height (widget));
/* Initialize the surface to white */
clear_surface ();
/* We've handled the configure event, no need for further processing. */
return TRUE;
}
/* Redraw the screen from the surface. Note that the ::draw
* signal receives a ready-to-be-used cairo_t that is already
* clipped to only draw the exposed areas of the widget
*/
static gboolean
draw_cb (GtkWidget *widget,
cairo_t *cr,
gpointer data)
{
cairo_set_source_surface (cr, surface, 0, 0);
cairo_paint (cr);
return FALSE;
}
/* Draw a rectangle on the surface at the given position */
static void
draw_brush (GtkWidget *widget,
gdouble x,
gdouble y)
{
cairo_t *cr;
/* Paint to the surface, where we store our state */
cr = cairo_create (surface);
cairo_rectangle (cr, x - 3, y - 3, 6, 6);
cairo_fill (cr);
cairo_destroy (cr);
/* Now invalidate the affected region of the drawing area. */
gtk_widget_queue_draw_area (widget, x - 3, y - 3, 6, 6);
}
/* Handle button press events by either drawing a rectangle
* or clearing the surface, depending on which button was pressed.
* The ::button-press signal handler receives a GdkEventButton
* struct which contains this information.
*/
static gboolean
button_press_event_cb (GtkWidget *widget,
GdkEventButton *event,
gpointer data)
{
/* paranoia check, in case we haven't gotten a configure event */
if (surface == NULL)
return FALSE;
if (event->button == GDK_BUTTON_PRIMARY)
{
draw_brush (widget, event->x, event->y);
}
else if (event->button == GDK_BUTTON_SECONDARY)
{
clear_surface ();
gtk_widget_queue_draw (widget);
}
/* We've handled the event, stop processing */
return TRUE;
}
/* Handle motion events by continuing to draw if button 1 is
* still held down. The ::motion-notify signal handler receives
* a GdkEventMotion struct which contains this information.
*/
static gboolean
motion_notify_event_cb (GtkWidget *widget,
GdkEventMotion *event,
gpointer data)
{
/* paranoia check, in case we haven't gotten a configure event */
if (surface == NULL)
return FALSE;
if (event->state & GDK_BUTTON1_MASK)
draw_brush (widget, event->x, event->y);
/* We've handled it, stop processing */
return TRUE;
}
static void
close_window (void)
{
if (surface)
cairo_surface_destroy (surface);
}
static void
activate (GtkApplication *app,
gpointer user_data)
{
GtkWidget *window;
GtkWidget *frame;
GtkWidget *drawing_area;
window = gtk_application_window_new (app);
gtk_window_set_title (GTK_WINDOW (window), "Drawing Area");
g_signal_connect (window, "destroy", G_CALLBACK (close_window), NULL);
gtk_container_set_border_width (GTK_CONTAINER (window), 8);
frame = gtk_frame_new (NULL);
gtk_frame_set_shadow_type (GTK_FRAME (frame), GTK_SHADOW_IN);
gtk_container_add (GTK_CONTAINER (window), frame);
drawing_area = gtk_drawing_area_new ();
/* set a minimum size */
gtk_widget_set_size_request (drawing_area, 100, 100);
gtk_container_add (GTK_CONTAINER (frame), drawing_area);
/* Signals used to handle the backing surface */
g_signal_connect (drawing_area, "draw",
G_CALLBACK (draw_cb), NULL);
g_signal_connect (drawing_area,"configure-event",
G_CALLBACK (configure_event_cb), NULL);
/* Event signals */
g_signal_connect (drawing_area, "motion-notify-event",
G_CALLBACK (motion_notify_event_cb), NULL);
g_signal_connect (drawing_area, "button-press-event",
G_CALLBACK (button_press_event_cb), NULL);
/* Ask to receive events the drawing area doesn't normally
* subscribe to. In particular, we need to ask for the
* button press and motion notify events that want to handle.
*/
gtk_widget_set_events (drawing_area, gtk_widget_get_events (drawing_area)
| GDK_BUTTON_PRESS_MASK
| GDK_POINTER_MOTION_MASK);
gtk_widget_show_all (window);
}
int
main (int argc,
char **argv)
{
GtkApplication *app;
int status;
app = gtk_application_new ("org.gtk.example", G_APPLICATION_FLAGS_NONE);
g_signal_connect (app, "activate", G_CALLBACK (activate), NULL);
status = g_application_run (G_APPLICATION (app), argc, argv);
g_object_unref (app);
return status;
}
#包括
/*用于存储当前涂鸦的曲面*/
静态cairo_surface_t*surface=NULL;
静态空隙
清除表面(空隙)
{
开罗*cr;
cr=cairo_创建(曲面);
cairo_set_source_rgb(cr,1,1,1);
开罗漆(cr);
开罗大学(cr);
}
/*创建一个大小合适的新曲面来存储我们的涂鸦*/
静态gboolean
配置事件cb(GtkWidget*小部件,
GdkEventConfigure*事件,
gpointer数据)
{
如果(表面)
开罗·表面·破坏(表面);
曲面=gdk_窗口_创建_相似_曲面(gtk_小部件_获取_窗口(小部件)),
开罗(内容)(颜色),,
gtk_小部件_获取_分配的_宽度(小部件),
gtk_小部件_获取_分配_高度(小部件));
/*将曲面初始化为白色*/
清除表面();
/*我们已处理配置事件,无需进一步处理*/
返回TRUE;
}
/*从表面重新绘制屏幕。注意::draw
*信号接收一个已准备好使用的CAROU\t
*剪裁为仅绘制小部件的暴露区域
*/
静态gboolean
draw_cb(GtkWidget*小部件,
开罗,
gpointer数据)
{
cairo_集_源_曲面(cr,曲面,0,0);
开罗漆(cr);
返回FALSE;
}
/*在给定位置的曲面上绘制一个矩形*/
静态空隙
画笔(GtkWidget*小部件,
gdouble x,
gdouble y)
{
开罗*cr;
/*在我们存储状态的表面上涂漆*/
cr=cairo_创建(曲面);
cairo_矩形(cr,x-3,y-3,6,6);
开罗填料(cr);
开罗大学(cr);
/*现在使绘图区域的受影响区域无效*/
gtk_小部件_队列_绘图区(小部件,x-3,y-3,6,6);
}
/*通过绘制一个矩形来处理按钮按下事件
*或清除表面,取决于按下哪个按钮。
*::按钮按下信号处理程序接收GdkEventButton
*包含此信息的结构。
*/
静态gboolean
按钮按下事件cb(GtkWidget*小部件,
GdkEventButton*事件,
gpointer数据)
{
/*偏执狂检查,以防我们没有收到配置事件*/
如果(曲面==NULL)
返回FALSE;
如果(事件->按钮==GDK\U按钮\U主)
{
画笔(小部件,事件->x,事件->y);
}
else if(事件->按钮==GDK\U按钮\U辅助)
{
清除表面();
gtk_小部件_队列_绘制(小部件);
}
/*我们已处理该事件,请停止处理*/
返回TRUE;
}
/*如果按钮1处于激活状态,则通过继续绘制来处理运动事件
*还是压着。::motion notify信号处理程序接收
*包含此信息的GdkEventMotion结构。
*/
静态gboolean
运动通知事件cb(GtkWidget*小部件,
GdkEventMotion*事件,
gpointer数据)
{
/*偏执狂检查,以防我们没有收到配置事件*/
如果(曲面==NULL)
返回FALSE;
如果(事件->状态和GDK_按钮1_掩码)
画笔(小部件,事件->x,事件->y);
/*我们已经处理好了,停止处理*/
返回TRUE;
}
静态空隙
关闭窗口(无效)
{
如果(表面)
开罗·表面·破坏(表面);
}
静态空隙
激活(GTK应用程序*应用程序,
gpointer用户(U数据)
{
GtkWidget*窗口;
GtkWidget*框架;
GtkWidget*绘图区域;
窗口=gtk_应用程序_窗口_新(应用程序);
gtk_窗口设置标题(gtk_窗口(窗口),“绘图区域”);
g_信号连接(窗口,“销毁”,g_回调(关闭窗口),空);
gtk_容器_设置_边框_宽度(gtk_容器(窗口),8);
frame=gtk_frame_new(空);
gtk_帧_集_阴影_类型(gtk_帧(帧),gtk_阴影_-IN);
gtk_容器添加(gtk_容器(窗口),框架);
图纸面积=gtk图纸面积新();
/*设定最小尺寸*/
gtk_小部件_设置_大小_请求(绘图区域,100100);
gtk_容器添加(gtk_容器(框架),绘图区域);
/*用于处理背衬表面的信号*/
g_信号连接(绘图区域,“绘图”,
G_回调(draw_cb),空;
g_信号连接(绘图区域,“配置事件”,
G_回调(配置_事件_cb),NULL);
/*事件信号*/
g_信号连接(绘图区域,“运动通知事件”,
G_回调(运动通知事件cb),空;
g_信号连接(绘图区域,“按钮按下事件”,
G_回调(按钮按下事件断路器),NULL);
/*请求接收绘图区域不正常的事件
*订阅。特别是,我们需要请求
*按钮按下和运动通知要处理的事件。
*/
gtk_小部件设置_事件(绘图区、gtk_小部件获取_事件(绘图区)
|GDK_按钮_按下_遮罩
|GDK_指针_运动_遮罩);
gtk_小部件_全部显示(窗口);
}
int
主(内部argc,
字符**argv)
{
GTK应用程序*app;
#include <cairo.h>
#include <gtk/gtk.h>
static void draw_rect (cairo_t *cr)
{
cairo_rectangle (cr, 10, 10, 180, 180); /* set rectangle */
cairo_set_source_rgb (cr, 0.3, 0.4, 0.6); /* set fill color */
cairo_fill (cr); /* fill rectangle */
}
static gboolean on_draw_event (GtkWidget *widget, cairo_t *cr,
gpointer user_data)
{
draw_rect (cr); /* draw rectangle in window */
return FALSE;
(void)user_data, (void)widget; /* suppress -Wunused warning */
}
int main (int argc, char *argv[])
{
GtkWidget *window; /* gtk windows */
GtkWidget *darea; /* cairo drawing area */
gtk_init (&argc, &argv); /* required with every gtk app */
window = gtk_window_new (GTK_WINDOW_TOPLEVEL); /* create window */
darea = gtk_drawing_area_new(); /* create cairo area */
gtk_container_add (GTK_CONTAINER(window), darea); /* add to window */
/* connect callbacks to draw rectangle and close window/quit app */
g_signal_connect (G_OBJECT(darea), "draw",
G_CALLBACK(on_draw_event), NULL);
g_signal_connect (G_OBJECT(window), "destroy",
G_CALLBACK(gtk_main_quit), NULL);
gtk_widget_show_all (window); /* show all windows */
gtk_main(); /* pass control to gtk event-loop */
}
gcc -Wall -Wextra -pedantic -std=c11 -O3 `pkg-config --cflags --libs gtk+-3.0`
$ ./bin/cairo_rectangle_min