diff --git a/src/texture/Image.cc b/src/texture/Image.cc
index 67ff8b1..408b713 100644
--- a/src/texture/Image.cc
+++ b/src/texture/Image.cc
@@ -36,9 +36,9 @@ Rgba Image::pixelAt(int x, int y) const {
 }
 
 Rgba Image::pixelUv(float u, float v) const {
-    int x = u * _width;
-    int y = v * _height;
-
+    int x = (u * _width) -1; //不管_width还是_height都是从0开始的，
+    int y = (v * _height) -1;//所以这里要减去1
+    
     return pixelAt(x, y);
     //return Rgba(255,0,0);
 }
diff --git a/src/texture/Raster.cc b/src/texture/Raster.cc
index dc27742..dfd333c 100644
--- a/src/texture/Raster.cc
+++ b/src/texture/Raster.cc
@@ -32,6 +32,52 @@ Raster::~Raster() {
     delete buffer;
 }
 
+void Raster::drawLine(float2 p1, float2 p2, Rgba color) {
+
+    float xOffer = p1.x - p2.x;
+    float yOffer = p1.y - p2.y;
+    float xStart, xEnd, yStart, yEnd;
+
+    if (xOffer == 0 && yOffer == 0) {
+        setPixel(p1.x, p1.y, color);
+    }
+
+
+    if (fabs(xOffer) > fabs(yOffer)) {
+        if (p1.x < p2.x) {
+            xStart = p1.x;
+            xEnd = p2.x;
+            yEnd = p2.y;
+        } else {
+            xStart = p2.x;
+            xEnd = p1.x;
+            yEnd = p1.y;
+        }
+
+        float slope = yOffer / xOffer;
+        for (float i = xStart; i < xEnd; i += 1.0) {
+            float q = yEnd - slope * (xEnd - i);
+            setPixel(i, q, color);
+        }
+    } else {
+        if (p1.y < p2.y) {
+            yStart = p1.y;
+            yEnd = p2.y;
+            xEnd = p2.x;
+        } else {
+            yStart = p2.y;
+            yEnd = p1.y;
+            xEnd = p1.x;
+        }
+        float slope = xOffer / yOffer;
+        for (float i = yStart; i < yEnd; i += 1.0) {
+            float q = xEnd - slope * (yEnd - i);
+            setPixel(q, i, color);
+        }
+    }
+
+}
+
 void Raster::drawPoint(int x, int y, Rgba color, int pointSize) {
     switch (pointSize) {
         case 1:
@@ -85,7 +131,7 @@ void Raster::drawSpan(const Span &span, Image* image) {
         } else {
             scale = (float) (i - startX) / length;
         }
-
+        
         uv = uvLerp(span.uvStart, span.uvEnd, scale);
 
         color = image->pixelUv(uv.x, uv.y);
@@ -127,7 +173,7 @@ void Raster::drawEge(const Ege& e1, const Ege& e2, Image* image) {
         }
         uvE2 = uvLerp(e2.uv2, e2.uv1, scale2);
         scale2 += setp2;
-        //setPixel(x2, y, e2.color2);
+        //setPixel(x2, y, Rgba(255,0,0));
 
 
         int x1;
@@ -138,9 +184,9 @@ void Raster::drawEge(const Ege& e1, const Ege& e2, Image* image) {
         }
         uvE1 = uvLerp(e1.uv2, e1.uv1, scale1);
         scale1 += setp1;
-        //setPixel(x1, y, e1.color2);
+        //setPixel(x1, y, Rgba(255,0,0));
 
-        Span span(x1, x2, y, Rgba(255,255,255), Rgba(255,255,255), uvE1, uvE2);
+        Span span(x1, x2, y, Rgba(255, 255, 255), Rgba(255, 255, 255), uvE1, uvE2);
         drawSpan(span, image);
     }
 }
@@ -166,6 +212,7 @@ void Raster::drawTriangle(const Vertex& vertex, Image* image) {
     for (int i = 1; i < 3; i++) {
         curLength = eges[i].y2 - eges[i].y1;
         if (curLength > length) {
+            length = curLength;
             iMax = i;
         }
     }
diff --git a/src/texture/Raster.h b/src/texture/Raster.h
index 83d550f..b1e2deb 100644
--- a/src/texture/Raster.h
+++ b/src/texture/Raster.h
@@ -114,6 +114,7 @@ public:
     Rgba* buffer;
     Raster(int width, int height);
     virtual ~Raster();
+    void drawLine(float2 p1, float2 p2, Rgba color);
     void drawPoint(int x, int y, Rgba color = Rgba(255, 0, 0, 0), int pointSize = 1);
     void drawSpan(const Span &span, Image* image);
     void drawEge(const Ege& e1, const Ege& e2, Image* image);
diff --git a/src/texture/texture.cc b/src/texture/texture.cc
index a26c7ca..2402104 100644
--- a/src/texture/texture.cc
+++ b/src/texture/texture.cc
@@ -20,13 +20,14 @@ Raster raster(width, height);
 void example() {
     Image* image = Image::loadFromFile("/home/blobt/Documents/dev/cpp/3dbase/image/scale.jpg");
 
-    Raster::Vertex ver1 = {
-        int2(10, 10), float2(0.0f, 0.0f), Rgba(),
-        int2(10, 110), float2(0.0f, 1.0f), Rgba(),
-        int2(110, 10), float2(1.0f, 0.0f), Rgba()
-    };
+        Raster::Vertex ver1 = {
+            int2(10, 10), float2(0.0f, 0.0f), Rgba(),
+            int2(10, 110), float2(0.0f, 1.0f), Rgba(),
+            int2(110, 10), float2(1.0f, 0.0f), Rgba()
+        };
+    
+        raster.drawTriangle(ver1, image);
 
-    raster.drawTriangle(ver1, image);
 
 
     Raster::Vertex ver2 = {
@@ -37,6 +38,11 @@ void example() {
 
     raster.drawTriangle(ver2, image);
 
+//    raster.drawPoint(10, 110, Rgba(255, 0, 0, 0), 3);
+//    raster.drawPoint(110, 10, Rgba(255, 0, 0, 0), 3);
+
+    //raster.drawLine(float2(10, 110), float2(110, 10), Rgba(255, 255, 255));
+
     delete image;
 }