added read() method to BMP class, filled in getWidth() and getHeight()

git-svn-id: svn://anubis/gvsu@202 45c1a28c-8058-47b2-ae61-ca45b979098e

cs677/pa3/BMP.cc

@@ -91,6 +91,30 @@ bool BMP::create(char * fileName, int width, int height, unsigned char * data)
     return (m_fp != NULL);
 }
 
+void BMP::read(unsigned char * buf)
+{
+    if (m_fp != NULL)
+    {
+        int row_data_bytes = 3 * m_info.width;
+        int row_padding = row_data_bytes & 0x3;
+        if (row_padding)
+            row_padding = 4 - row_padding;
+        fseek(m_fp,
+              (m_header.offset != 0
+                  ? m_header.offset
+                  : sizeof(m_header) + sizeof(m_info))
+              SEEK_SET);
+        unsigned char * data_ptr = buf + row_data_bytes * (m_info.height - 1);
+        for (int i = 0; i < m_info.height; i++)
+        {
+            fread(data_ptr, row_data_bytes, 1, m_fp);
+            if (row_padding)
+                fseek(m_fp, row_padding, SEEK_CUR);
+            data_ptr -= row_data_bytes;
+        }
+    }
+}
+
 void BMP::close()
 {
     if (m_fp != NULL)

cs677/pa3/BMP.h

@@ -34,8 +34,9 @@ public:
     BMP(char * fileName);
     BMP(char * fileName, int width, int height, unsigned char * data);
     ~BMP();
-    int     getWidth();
+    void    read(unsigned char * buf);
-    int     getHeight();
+    int     getWidth() { return m_info.width; }
+    int     getHeight() { return m_info.height; }
 
 private:
     FILE *      m_fp;