## gd库例子
>下面例子全部 可以直接使用woo控制台运行，简单方便
1.使用`woo -rc` 或 `woo -run_console` 来启动woo控制台交互界面
2.输入`:C` 或 `;;;` 启动多行输入模式，
3.复制下方的代码，粘贴到控制台输入
4.再输入：`:R` 或 `;;;`来运行多行输入的代码，即可看到结果
1.）gd 绘图库测试:绘制椭圆
```lua|woo
local gd = woo.gd:new()
local wh = 1024
gd:create(wh, wh) -- 创建一个正方形画布: 1024 X 1024
gd:setRGBA(0, 0, 0, 0.1)
for i = 0, 360, 15 do
gd:push()
gd:rotateAbout(i, wh / 2, wh / 2)
gd:drawEllipse(wh / 2, wh / 2, wh * 7 / 16, wh / 8)
gd:fill()
gd:pop()
end
-- save png file to desktop folder
local save_file = _home() .. "/Desktop/out.png"
local file_quality = 80
-- 可以保存为jpg
--local err = gd:saveJpg(save_file, file_quality)
local err = gd:savePng(save_file)
print(err)
_show(save_file) -- 显示保存的图片（注意：只有gui桌面才能显示图片，服务器类不能显示图片，请下载图片后自行查看）
```
输出：
2.)路径曲线绘画
```lua|woo
local gd = woo.gd:new()
function random()
return _rand() * 2 - 1
end
function point()
return random(), random()
end
function drawCurve(gd)
gd:setRGBA(0, 0, 0, 0.1)
gd:fillPreserve()
gd:setRGB(0, 0, 0)
gd:setLineWidth(12)
gd:stroke()
end
function drawPoints(gd)
gd:setRGBA(1, 0, 0, 0.5)
gd:setLineWidth(2)
gd:stroke()
end
function randomQuadratic(gd)
local x0, y0 = point()
local x1, y1 = point()
local x2, y2 = point()
gd:moveTo(x0, y0)
gd:quadraticTo(x1, y1, x2, y2)
drawCurve(gd)
gd:moveTo(x0, y0)
gd:lineTo(x1, y1)
gd:lineTo(x2, y2)
drawPoints(gd)
end
function randomCubic(gd)
local x0, y0 = point()
local x1, y1 = point()
local x2, y2 = point()
local x3, y3 = point()
gd:moveTo(x0, y0)
gd:cubicTo(x1, y1, x2, y2, x3, y3)
-- print(x1, y1, x2, y2, x3, y3)
drawCurve(gd)
gd:moveTo(x0, y0)
gd:lineTo(x1, y1)
gd:lineTo(x2, y2)
gd:lineTo(x3, y3)
drawPoints(gd)
end
local S = 256
local W = 8
local H = 8
gd:create(S * W, S * H)
gd:setRGB(1, 1, 1)
gd:clear()
for j = 0, H - 1, 1 do
for i = 0, W - 1, 1 do
local x = i * S + S / 2
local y = j * S + S / 2
print(x, y)
gd:push()
gd:translate(x, y)
gd:scale(S / 2, S / 2)
if j % 2 == 0 then
randomCubic(gd)
else
randomQuadratic(gd)
end
gd:pop()
end
end
gd:savePng("out1.png")
_show("out1.png")
```
**输出（如果安装了去广告插件，这个图片不能显示，这个图片看云官方使用md5前两位ad作为目录值，被广告插件屏蔽，群里反馈无果，所以广告插件请停止此页面的拦截）：**
3.）文字描边
```lua|woo
-- bitmap 绘图库测试:meme
local gd = woo.gd:new()
local S = 1024
gd:create(S, S) -- 创建一个正方形画布: 1024 X 1024
gd:setRGB(1, 1, 1)
gd:clear()
-- 运行前请把下方字体替换下，目前是deepin系统下的字体
local e = gd:loadFontFace('/usr/share/fonts/truetype/lato/Lato-Medium.ttf', 90)
print('loadFontFace:', e)
gd:setRGB(0, 0, 0)
local s = "ONE DOES NOT SIMPLY"
local n = 5 -- // "stroke" size
local times = 0
for dy = -n, n, 1 do
for dx = -n, n, 1 do
if dx * dx + dy * dy >= n * n then
-- // give it rounded corners
-- continue
else
times = times + 1
local x = S / 2 + (dx)
local y = S / 2 + (dy)
gd:drawStringAnchored(s, x, y, 0.5, 0.5)
end
end
end
gd:setRGB(1, 1, 1)
gd:drawStringAnchored(s, S / 2, S / 2, 0.5, 0.5)
local err = gd:savePng("out.png")
print(times, err)
_show("out.png") -- 显示保存的图片（注意：只有gui桌面才能显示图片，服务器类不能显示图片，请下载图片后自行查看）
```
**输出：**
3.)路径绘制，描边：五角星
```lua|woo
local dc=woo.gd:new()
function Point(x,y)
return {X=x,Y=y}
end
function Polygon(n)
local result = {}
for i = 0 ,n,1 do
-- body
a = (i)*2*math.pi/ (n) - math.pi/2
result[i] = Point(math.cos(a), math.sin(a))
end
return result
end
local W = 1200
local H = 120
local S = 100
dc:create(W, H)
dc:setHexColor("#FFFFFF")
dc:clear()
local n = 5
local points = Polygon(n)
for x = S / 2, W, S do
dc:push()
local s = _rand()*S/4 + S/4
dc:translate( (x), H/2)
dc:rotate( _rand() * 2 * math.pi)
dc:scale(s, s)
for i = 0, n, 1 do
local index = (i * 2) % n
local p = points[index]
dc:lineTo(p.X, p.Y)
end
dc:setLineWidth(10)
dc:setHexColor("#FFCC00")
dc:strokePreserve()
dc:setHexColor("#FFE43A")
dc:fill()
dc:pop()
end
dc:savePng("out.png")
_show('out.png')
```
**输出：**
4.)绘制chart
```lua|woo
local dc=woo.gd:new()
function CreatePoints(n)
local points = {}
for i = 0,n, 1 do
local x = 0.09+ _rand() *0.7
local y = 0.1 * _rand() + (_rand()>0.5 and x or -x)
y=math.abs(y)
points[i] = {X=x,Y=y}
_out(_rand(),'\n')
end
return points
end
local S = 1024
local P = 64
dc:create(S, S)
dc:invertY()
dc:setRGB(1, 1, 1)
dc:clear()
local points = CreatePoints(500)
dc:translate(P, P)
dc:scale(S-P*2, S-P*2)
-- // draw minor grid
for i = 1, 10, 1 do
local x = (i) / 10
dc:moveTo(x, 0)
dc:lineTo(x, 1)
dc:moveTo(0, x)
dc:lineTo(1, x)
end
dc:setRGBA(0, 0, 0, 0.25)
dc:setLineWidth(1)
dc:stroke()
-- // draw axes
dc:moveTo(0, 0)
dc:lineTo(1, 0)
dc:moveTo(0, 0)
dc:lineTo(0, 1)
dc:setRGB(0, 0, 0)
dc:setLineWidth(4)
dc:stroke()
-- // draw points
dc:setRGBA(0, 0, 1, 0.5)
for _, p in pairs(points) do
dc:drawCircle(p.X, p.Y, 3.0/S)
dc:fill()
end
-- // draw text
dc:identity()
dc:setRGB(0, 0, 0)
-- 运行前请把下方字体替换下，目前是deepin系统下的字体
local font_path='/usr/share/fonts/truetype/lato/Lato-Medium.ttf'
if dc:loadFontFace(font_path, 24) then
print(err)
end
dc:drawStringAnchored("Chart Title", S/2, P/2, 0.5, 0.5)
if dc:loadFontFace(font_path, 18) then
print(err)
end
dc:drawStringAnchored("X Axis Title", S/2, S-P/2, 0.5, 0.5)
dc:savePng("out.png")
_show('out.png')
```
**输出：**
5.)色盘绘制
```lua|woo
local dc=woo.gd:new()
dc:create(500, 400)
grad = dc:newLinearGradient(20, 320, 400, 20)
grad:addColorStop(0, 0, 255, 0, 255 )
grad:addColorStop(1, 0, 0, 255, 255 )
grad:addColorStop(0.5, 255, 0, 0, 255 )
dc:setHexColor('#fff')
dc:drawRectangle(20, 20, 400-20, 300)
dc:stroke()
dc:setStrokeStyle(grad)
dc:setLineWidth(4)
dc:moveTo(10, 10)
dc:lineTo(410, 10)
dc:lineTo(410, 100)
dc:lineTo(10, 100)
dc:closePath()
dc:stroke()
dc:setFillStyle(grad)
dc:moveTo(10, 120)
dc:lineTo(410, 120)
dc:lineTo(410, 300)
dc:lineTo(10, 300)
dc:closePath()
dc:fill()
dc:savePng("out.png")
_show('out.png') -- 在服务器中无效
```
**输出：**
6.)普通文本绘制
```lua|woo
local dc=woo.gd:new()
local S = 1024
dc:create(S, S)
dc:create()
dc:setRGB(1, 1, 1)
dc:clear()
dc:setRGB(0, 0, 0)
-- 运行前替换下方字体，绝对路径
dc:loadFontFace("/usr/share/fonts/truetype/lato/Lato-Medium.ttf", 96)
dc:drawStringAnchored("Hello, world! 你好，世界！", S/2, S/2, 0.5, 0.5)
dc:savePng("out.png")
_show('out.png')
```
7.)绘制表格
```lua|woo
local dc=woo.gd:new()
local W = 1000
local H = 1000
local Minor = 10
local Major = 100
dc :create(W, H)
dc:setRGB(1, 1, 1)
dc:clear()
-- // minor grid
for x = Minor, W-1, Minor do
fx = (x) + 0.5
dc:drawLine(fx, 0, fx, H)
end
for y = Minor, H-1, Minor do
fy = (y) + 0.5
dc:drawLine(0, fy, W, fy)
end
dc:setLineWidth(1)
dc:setRGBA(0, 0, 0, 0.25)
dc:stroke()
-- // major grid
for x = Major, W-1, Major do
fx = (x) + 0.5
dc:drawLine(fx, 0, fx, H)
end
for y = Major, H-1, Major do
fy = (y) + 0.5
dc:drawLine(0, fy, W, fy)
end
dc:setLineWidth(1)
dc:setRGBA(0, 0, 0, 0.5)
dc:stroke()
dc:savePng("out.png")
_show('out.png')
```
**输出：**
*****
8.)画直线
```lua
local dc=woo.gd:new()
local W = 1024
local H = 1024
dc:create(W, H)
dc:setRGB(0, 0, 0)
dc:clear()
for i = 0,1000-1,1 do
local x1 = _rand() * W
local y1 = _rand() * H
local x2 = _rand() * W
local y2 = _rand() * H
local r = _rand()
local g = _rand()
local b = _rand()
local a = _rand()*0.5 + 0.5
local w = _rand()*4 + 1
dc:setRGBA(r, g, b, a)
dc:setLineWidth(w)
dc:drawLine(x1, y1, x2, y2)
dc:stroke()
end
dc:savePng("out.png")
_show('out.png')
```
**输出：**
*****
9.)填充
```lua|woo
local dc=woo.gd:new()
dc:create(1000, 1000)
for j = 0, 10-1,1 do
for i = 0,10-1,1 do
x = (i)*100 + 50
y = (j)*100 + 50
a1 = _rand() * 2 * math.pi
a2 = a1 + _rand()*math.pi + math.pi/2
dc:drawArc(x, y, 40, a1, a2)
print(x, y, 40, a1, a2)
-- dc:closePath()
end
end
dc:setRGB(0, 0, 0)
dc:fillPreserve()
dc:setRGB(1, 1, 1)
dc:setLineWidth(8)
dc:strokePreserve()
dc:setRGB(1, 0, 0)
dc:setLineWidth(4)
dc:strokePreserve()
dc:savePng("out.png")
_show('out.png')
```
**输出：**
*****
10.)圆形填充
```lua|woo
local dc=woo.gd:new()
local S = 1024
local N = 2048
dc:create(S, S)
dc:setRGB(1, 1, 1)
dc:clear()
dc:setRGB(0, 0, 0)
for i = 0, N-1,1 do
local t = (i) / N
local d = t*S*0.4 + 10
local a = t * math.pi * 2 * 20
local x = S/2 + math.cos(a)*d
local y = S/2 + math.sin(a)*d
local r = t * 8
dc:drawCircle(x, y, r)
end
dc:fill()
dc:savePng("out.png")
_show('out.png')
```
**输出：**
11.)文本排版换行
```lua|woo
local dc=woo.gd:new()
local TEXT = "Call me Ishmael. Some years ago—never mind how long precisely—having little or no money in my purse, and nothing particular to interest me on shore, I thought I would sail about a little and see the watery part of the world. It is a way I have of driving off the spleen and regulating the circulation. Whenever I find myself growing grim about the mouth; whenever it is a damp, drizzly November in my soul; whenever I find myself involuntarily pausing before coffin warehouses, and bringing up the rear of every funeral I meet; and especially whenever my hypos get such an upper hand of me, that it requires a strong moral principle to prevent me from deliberately stepping into the street, and methodically knocking people's hats off—then, I account it high time to get to sea as soon as I can. This is my substitute for pistol and ball. With a philosophical flourish Cato throws himself upon his sword; I quietly take to the ship. There is nothing surprising in this. If they but knew it, almost all men in their degree, some time or other, cherish very nearly the same feelings towards the ocean with me."
local W = 1024
local H = 1024
local P = 16
dc:create(W, H)
dc:setRGB(1, 1, 1)
dc:clear()
dc:drawLine(W/2, 0, W/2, H)
dc:drawLine(0, H/2, W, H/2)
dc:drawRectangle(P, P, W-P-P, H-P-P)
dc:setRGBA(0, 0, 1, 0.25)
dc:setLineWidth(3)
dc:stroke()
dc:setRGB(0, 0, 0)
dc:loadFontFace("/usr/share/fonts/truetype/lato/Lato-Medium.ttf", 18)
dc:drawStringWrapped("UPPER LEFT", P, P, 0, 0, 0, 1.5, woo.gd.ALIGN_LEFT)
dc:drawStringWrapped("UPPER RIGHT", W-P, P, 1, 0, 0, 1.5, woo.gd.ALIGN_RIGHT)
dc:drawStringWrapped("BOTTOM LEFT", P, H-P, 0, 1, 0, 1.5, woo.gd.ALIGN_LEFT)
dc:drawStringWrapped("BOTTOM RIGHT", W-P, H-P, 1, 1, 0, 1.5, woo.gd.ALIGN_RIGHT)
dc:drawStringWrapped("UPPER MIDDLE", W/2, P, 0.5, 0, 0, 1.5, woo.gd.ALIGN_CENTER)
dc:drawStringWrapped("LOWER MIDDLE", W/2, H-P, 0.5, 1, 0, 1.5, woo.gd.ALIGN_CENTER)
dc:drawStringWrapped("LEFT MIDDLE", P, H/2, 0, 0.5, 0, 1.5, woo.gd.ALIGN_LEFT)
dc:drawStringWrapped("RIGHT MIDDLE", W-P, H/2, 1, 0.5, 0, 1.5, woo.gd.ALIGN_RIGHT)
dc:loadFontFace("/usr/share/fonts/truetype/lato/Lato-Medium.ttf", 12)
dc:drawStringWrapped(TEXT, W/2-P, H/2-P, 1, 1, W/3, 1.75, woo.gd.ALIGN_LEFT)
dc:drawStringWrapped(TEXT, W/2+P, H/2-P, 0, 1, W/3, 2, woo.gd.ALIGN_LEFT)
dc:drawStringWrapped(TEXT, W/2-P, H/2+P, 1, 0, W/3, 2.25, woo.gd.ALIGN_LEFT)
dc:drawStringWrapped(TEXT, W/2+P, H/2+P, 0, 0, W/3, 2.5, woo.gd.ALIGN_LEFT)
dc:savePng("out.png")
_show('out.png')
```
12.)图片九宫格
```
local avatar = woo.gd:new()
-- 从桌面读取avatar.jpg图片
avatar:loadImage(_home() .. '/Desktop/' .. 'avatar.jpg')
-- 重新修改头像尺寸180*180像素
avatar:resize(180, 180, 0)
-- 新建一个正方形画布背景
local gd = woo.gd:new()
-- 创建头像，-- 初始化正方形画布背景
gd:create(180 * 3 + 5 * 3, 180 * 3 + 5 * 3)
-- 开始绘制头像图片到背景
for i = 1, 3 do
for j = 1, 3 do
gd:drawImage(avatar, (i - 1) * 180 + (i - 1) * 5, (j - 1) * 180 + (j - 1) * 5)
end
end
-- 保存最终到结果到 桌面 文件：9.png
gd:savePng(_home() .. '/Desktop/9.png')
```
**输出：**
13.)绘制圆形头像
~~~
local gd = woo.gd:new()
--加载桌面到avatar.jpg文件，请自己修改对于到图片路径
gd:loadImage(_home() .. '/Desktop/avatar.jpg')
-- 这里设置0表示圆角头像
gd:setBorderRadius(0)
gd:savePng(_home() .. '/Desktop/r.png')
~~~
**输出：**
14.)绘制圆角头像
~~~
local gd = woo.gd:new()
--加载桌面到avatar.jpg文件，请自己修改对于到图片路径
gd:loadImage(_home() .. '/Desktop/avatar.jpg')
-- 这里设置8表示圆角为8像素
gd:setBorderRadius(8)
gd:savePng(_home() .. '/Desktop/r.png')
~~~
**输出：**
*****
15.)图像合成
~~~
local avatar = woo.gd:new()
-- 加载正方形头像
avatar:loadImage(_home() .. '/Desktop/avatar.jpg')
-- 重新修改头像尺寸
avatar:resize(144, 144, 0)
-- 设置圆形头像
avatar:setBorderRadius(0)
---头像外框
local avatar_bord = woo.gd:new()
-- 加载头像外框
avatar_bord:loadImage(_home() .. '/Desktop/avatar_bord.png')
--- 背景画布
local background = woo.gd:new()
-- 背景创建一个空白画布
background:create(172, 200)
-- 绘制头像到空白画布
background:drawImage(avatar, 14, 13)
-- 绘制 头像边框到空白画布
background:drawImage(avatar_bord, 0, 0)
-- 保存最终结果到桌面p.png
background:savePng(_home() .. '/Desktop/p.png')
~~~
**输出：**
*****
16.)绘制验证码（可以去：[B站看视频教程](https://www.bilibili.com/video/BV1Go4y1U7CJ?from=search&seid=15377466184202674859&spm_id_from=333.337.0.0)）
```
-- woo语言生成验证码Demo
local dc = woo.gd:new()
local W = 160
local H = 50
dc:create(W, H)
-- 红绿蓝取值 0-1（0-255）
dc:setRGB(0, 0, 0)
--dc:setRGB255(255,255,255)
dc:clear()
-- 随机数种子
_rand(_time())
-- 随机设置绘制的颜色
local rgba = function()
local r = _rand()
local g = _rand()
local b = _rand()
local a = _rand() * 0.5 + 0.5
dc:setRGBA(r, g, b, a)
end
for i = 0, 10 do
local x1 = _rand() * W
local y1 = _rand() * H
local x2 = _rand() * W
local y2 = _rand() * H
local w = _rand() * 4 + 1
rgba()
dc:setLineWidth(w)
dc:drawLine(x1, y1, x2, y2)
dc:stroke()
end
if _os() == 'windows' then
dc:loadFontFace("C:\\Windows\\Fonts\\arial.ttf", 28)
else
-- unix系统，请设置对应的字体绝对路径
--dc:loadFontFace("***", 28)
end
-- 设置随机数种子
math.randomseed(_time())
local qstr = ''
for i = 1, 4 do
qstr = _chr(_rand() < .5 and math.random(65, 90) or math.random(97, 122))
dc:drawString(qstr, W / 5 * i, H / 2 + 10)
rgba()
end
-- png文件保存到桌面gd.png
local path = _home() .. '/Desktop/gd.png'
dc:savePng(path)
_show(path)
```
**输出**
- 序言
- 安装
- 可视化编辑器
- woo 命令行参数详解
- 测试用例
- 简单http服务
- 正则
- gpio控制硬件设备
- 比武不招亲
- 和php比WebServer
- woo语法
- 语法简介
- 基本语法
- woo数据类型
- woo变量
- woo循环
- woo流程控制
- woo函数
- woo运算符
- woo字符串
- 类
- 类的继承
- 模块
- 数组
- 迭代
- table
- 元表（魔术方法）
- 错误处理
- 面向对象
- woo开发必须注意事项
- 函数/模块
- 内置函数
- webServer专属函数
- 内置模块
- gd-2d绘图库
- 2D图形例子
- websockets用例
- buffer缓存
- http
- orm数据库连接
- redis-ssdb连接
- queue队列
- 其他特别函数
- sockets
- 启动线程如何
- Murphy-http Web框架
- 简介
- 全局函数
- model
- view
- controller
- 消息队列
- 全局线程锁
- 包管理器/coder wooyri package manager
- 最ok的包上榜名单
- woo栗子
- 函数传参
- 编码解码
- http模块用例
- 移动读写文件流用例
- 文件下载用例
- 数组迭代
- 进制转换
- _choose用例
- 日期时间用例
- 注明
- wop 码包|coder wooyri peogram
- 码人激励计划