added Blend.h and supported it.

inc/hgl/2d/Bitmap.h

@@ -5,6 +5,8 @@
 #include<hgl/math/HalfFloat.h>
 #include<iterator>
 namespace hgl
+{
+    namespace bitmap
     {
         template<typename T> 
         static void FillPixels(T *p,const T &color,const int length)
@@ -107,5 +109,6 @@ namespace hgl
                 delete[] temp;
             }
         };//template<typename T> class Bitmap
+    }//namespace bitmap
 }//namespace hgl
 #endif//HGL_2D_BITMAP_INCLUDE

inc/hgl/2d/Blend.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include<hgl/type/DataType.h>
+
+namespace hgl
+{
+    namespace bitmap
+    {
+        enum class BlendMode
+        {
+            NoBlend,            ///<不混合
+            Alpha,              ///<Alpha混合
+            Add,                ///<加法混合
+            Sub,                ///<减法混合
+        };//enum class BlendMode
+
+        template<typename T> struct BlendColor
+        {
+            BlendMode mode=BlendMode::NoBlend;
+
+        public:
+
+            virtual const T &BlendNoBlend(const T &src,const T &dst,const float alpha)
+            {
+                return src;
+            }
+
+            virtual const T &BlendAlpha(const T &src,const T &dst,const float alpha)
+            {
+                return src*alpha+dst*(1-alpha);
+            }
+
+            virtual const T &BlendAdd(const T &src,const T &dst,const float alpha)
+            {
+                return src*alpha+dst;
+            }
+
+            virtual const T &BlendSub(const T &src,const T &dst,const float alpha)
+            {
+                return src*alpha-dst;
+            }
+
+            virtual const T &Blend(const T &src,const T &dst,const float alpha)
+            {
+                switch(mode)
+                {
+                    case BlendMode::NoBlend:    return BlendNoBlend(src,dst,alpha);
+                    case BlendMode::Alpha:      return BlendAlpha(src,dst,alpha);
+                    case BlendMode::Add:        return BlendAdd(src,dst,alpha);
+                    case BlendMode::Sub:        return BlendSub(src,dst,alpha);
+                }
+
+                return src;
+            }
+        };//template<typename T> class BlendColor
+    }//namespace bitmap
+}//namespace hgl

inc/hgl/2d/DrawGeometry.h

@@ -1,9 +1,12 @@
 #pragma once
 
 #include<hgl/2d/Bitmap.h>
+#include<hgl/2d/blend.h>
 #include<hgl/math/FastTriangle.h>
 
 namespace hgl
+{
+    namespace bitmap
     {
         template<typename T> class DrawGeometry
         {
@@ -16,12 +19,17 @@ namespace hgl
             FormatBitmap *bitmap;
 
             T draw_color;
+            float alpha;
+
+            BlendColor<T> *blend;
 
         public:
 
             DrawGeometry(FormatBitmap *fb)
             {
                 bitmap=fb;
+                draw_color=0;
+                alpha=1;
             }
 
             virtual ~DrawGeometry()=default;
@@ -31,6 +39,26 @@ namespace hgl
                 draw_color=color;
             }
 
+            void SetBlend(BlendColor<T> *bc)
+            {
+                blend=bc;
+            }
+
+            virtual void SetBlend(const BlendMode &mode)
+            {
+                blend->mode=mode;                
+            }
+
+            void CloseBlend()
+            {
+                blend->mode=BlendMode.NoBlend;
+            }
+
+            void SetAlpha(const float &a)
+            {
+                alpha=a;
+            }
+
             bool GetPixel(int x,int y,T &color)
             {
                 if(!data)return(false);
@@ -52,7 +80,7 @@ namespace hgl
 
                 if(!p)return(false);
 
-            *p=draw_color;
+                *p=blend->Blend(draw_color,*p,alpha);
 
                 return(true);
             }
@@ -71,7 +99,10 @@ namespace hgl
 
                 if(length<=0)return(false);
 
-            FillPixels<T>(bitmap->GetData(x,y),draw_color,length);
+                T *p=bitmap->GetData(x,y);
+
+                for(int i=0;i<length;i++)
+                    *p++=blend->Blend(draw_color,*p,alpha);
 
                 return(true);
             }
@@ -93,8 +124,15 @@ namespace hgl
 
                 if(w<=0||h<=0)return(false);
 
+                T *p=bitmap->GetData(x,y);
+
                 for(int y=t;y<t+h;y++)
-                FillPixels<T>(bitmap->GetData(l,y),draw_color,w);
+                {
+                    for(int i=0;i<length;i++)
+                        *p++=blend->Blend(draw_color,*p,alpha);
+
+                    p+=width-w;
+                }
 
                 return(true);
             }
@@ -118,7 +156,7 @@ namespace hgl
 
                 for(int i=0;i<length;i++)
                 {
-                *p=draw_color;
+                    *p=blend->Blend(draw_color,*p,alpha);
                     p+=line_bytes;
                 }
 
@@ -406,4 +444,5 @@ namespace hgl
                 free(xy);
             }
         };//template<typename T,uint CHANNELS> class DrawGeometry
+    }//namespace bitmap
 }//namespace hgl