cocos2d-x mruby学习笔记--扩展2(mruby code)

ruby gems 的风格是除了c扩展，还可以添加ruby扩展，为什么我们不试一试呢，定义module.rb如下

module CC

class Vec2
alias_method :native_to_s,:to_s
def to_s
"%s[x:%f,y:%f]"%[self.native_to_s,self.x,self.y]
end
end

class Vec3
alias_method :native_to_s,:to_s
def to_s
"%s[x:%f,y:%f,z:%f]"%[self.native_to_s,self.x,self.y,self.z]
end
end

class Vec4
alias_method :native_to_s,:to_s
def to_s
"%s[x:%f,y:%f,z:%f,w:%f]"%[self.native_to_s,self.x,self.y,self.z,self.w]
end
end

class Size
alias_method :native_to_s,:to_s
def to_s
"%s[width:%f,height:%f]"%[self.native_to_s,self.width,self.height]
end
end

class Rect
alias_method :native_contains_point,:contains_point
alias_method :native_to_s,:to_s

def x
self.origin.x
end

def y
self.origin.y
end

def width
self.size.width
end

def height
self.size.height
end

def contains_point(x,y=nil)

if x.is_a?(Numeric) && y.is_a?(Numeric)
native_contains_point(CC::Vec2.new(x,y))
elsif x.is_a?(CC::Vec2)
native_contains_point(x)
else
raise "unknow args ,expect (Numeric x,Numeric y) or (CC::Vec2 vec)"
end
end

def to_s
"%s[x:%f,y:%f,width:%f,height:%f]"%[self.native_to_s,self.x,self.y,self.width,self.height]
end

end

class Color3B
alias_method :native_to_s,:to_s
def to_s
"%s[r:0x%02X,g:0x%02X,b:0x%02X]"%[self.native_to_s,self.r,self.g,self.b]
end
end

class Color4B
alias_method :native_to_s,:to_s
def to_s
"%s[r:0x%02X,g:0x%02X,b:0x%02X,a:0x%02X]"%[self.native_to_s,self.r,self.g,self.b,self.a]
end
end

class Color4F
alias_method :native_to_s,:to_s
def to_s
"%s[r:%f,g:%f,b:%f,a:%f]"%[self.native_to_s,self.r,self.g,self.b,self.a]
end
end

end

然后我们就需要mrbc工具了，这个工具可以将ruby代码转换为java风格的字节码，比如mrbc -BMODULE_CC_TO_S module.rb 会生成C风格的字节数组

/* dumped in little endian order.
use `mrbc -E` option for big endian CPU. */
#include <stdint.h>
const uint8_t
#if defined __GNUC__
__attribute__((aligned(4)))
#elif defined _MSC_VER
__declspec(align(4))
#endif
MODULE_CC_TO_S[] = {
0x45,0x54,0x49,0x52,0x30,0x30,0x30,0x33,0x7d,0xa5,0x00,0x00,0x0b,0x7e,0x4d,0x41,
0x54,0x5a,0x30,0x30,0x30,0x30,0x49,0x52,0x45,0x50,0x00,0x00,0x0b,0x12,0x30,0x30,
......
};

在任何你喜欢的地方。比如bool RubyEngine::init(void)中添加

int ai = mrb_gc_arena_save(_mrb);
mrb_load_irep(_mrb, MODULE_CC_TO_S);
if (_mrb->exc) {
mrb_print_error(_mrb);
exit(EXIT_FAILURE);
}
mrb_gc_arena_restore(_mrb, ai);

这样你就成功的扩展了自定义的一些方法，如果你不需要这样麻烦的话，也可以直接require 'module.rb'来扩展，这儿仅仅是一个示例。表示我们使用mruby代码能成功的扩展内置功能好了。我们来试一试吧

begin
size=CC::Size.new(200,200.1)
p size.to_s
p CC::Vec3.new(100,100,100).to_s
p CC::Vec4.new(100,100,100,100).to_s
vec2=CC::Vec2.new(50,50)
rect=CC::Rect.new(10,10,100,100)
p rect.to_s
p "contains_point(%d,%d) %s"%[vec2.x,vec2.y,rect.contains_point(vec2.x,vec2.y) ]
p "contains_point(%s) %s"%[vec2.to_s, rect.contains_point(vec2) ]

p CC::Color3B.new(0x00,0xff,0xcc).to_s
p CC::Color4B.new(0x00,0xff,0xcc,0xdd).to_s
p CC::Color4F.new(0x00,0xff,0xcc,0xdd).to_s
rescue RuntimeError=>exp
p exp.message
rescue StandardError=>exp
p exp.message
end

logcat 输出如下：

D/cocos2d-x debug info(14126): [RUBY] "#<CC::Size:0x7aa03f20>[width:200.000000,height:200.100006]"

D/cocos2d-x debug info(14126): [RUBY] "#<CC::Vec3:0x7aa03de8>[x:100.000000,y:100.000000,z:100.000000]"

D/cocos2d-x debug info(14126): [RUBY] "#<CC::Vec4:0x7aa03cc8>[x:100.000000,y:100.000000,z:100.000000,w:100.000000]"

D/cocos2d-x debug info(14126): [RUBY] "#<CC::Rect:0x7aa03b78>[x:10.000000,y:10.000000,width:100.000000,height:100.000000]

D/cocos2d-x debug info(14126): [RUBY] "contains_point(50,50) true"

D/cocos2d-x debug info(14126): [RUBY] "contains_point(#<CC::Vec2:0x7aa03b90>[x:50.000000,y:50.000000]) true"

D/cocos2d-x debug info(14126): [RUBY] "#<CC::Color3B:0x78fc9ed0>[r:0x00,g:0xFF,b:0xCC]"

D/cocos2d-x debug info(14126): [RUBY] "#<CC::Color4B:0x78fc9cd8>[r:0x00,g:0xFF,b:0xCC,a:0xDD]"

D/cocos2d-x debug info(14126): [RUBY] "#<CC::Color4F:0x78fc99d8>[r:0.000000,g:255.000000,b:204.000000,a:221.000000]"