Split console into two pages

src/hulk/console.d

@@ -16,18 +16,22 @@ import hulk.writef;
  */
 struct Console
 {
+    /** Border color. */
     private enum BORDER_COLOR = 0xFF8000u;
 
-    /** Console width in text columns. */
+    /** Console page width in text columns. */
     private static __gshared size_t m_width;
 
-    /** Console height in text rows. */
+    /** Console page height in text rows. */
     private static __gshared size_t m_height;
 
-    /** Current console cursor X position. */
+    /** Current console page. */
+    private static __gshared size_t m_page;
+
+    /** Current page cursor X position. */
     private static __gshared size_t m_x;
 
-    /** Current console cursor Y position. */
+    /** Current page cursor Y position. */
     private static __gshared size_t m_y;
 
     /**
@@ -36,7 +40,7 @@ struct Console
     public static void initialize()
     {
         size_t fb_console_height = Fb.height - Kfont.line_height - 1;
-        m_width = Fb.width / Kfont.advance;
+        m_width = (Fb.width - 1) / 2 / Kfont.advance;
         m_height = fb_console_height / Kfont.line_height;
     }
 
@@ -46,9 +50,10 @@ struct Console
     public static void clear()
     {
         Fb.clear();
+        m_page = 0u;
         m_x = 0u;
         m_y = 0u;
-        draw_header();
+        draw();
     }
 
     /**
@@ -65,7 +70,7 @@ struct Console
         }
         else
         {
-            render_char(m_x, m_y, ch);
+            render_char(fb_x(m_page, m_x), fb_y(m_y), ch);
             m_x++;
             if (m_x == m_width)
             {
@@ -75,49 +80,65 @@ struct Console
         }
         if (m_y == m_height)
         {
-            m_y--;
+            if (m_page == 0u)
-            Fb.copy_rows_up(fb_y(1u),
+            {
-                    (m_height - 1u) * Kfont.line_height,
+                m_page = 1u;
-                    Kfont.line_height);
+                m_x = 0u;
-            Fb.rect(0u, fb_y(m_height - 1u), fb_x(m_width), Kfont.line_height, 0u);
+                m_y = 0u;
+            }
+            else
+            {
+                m_y--;
+                shift_rows();
+            }
         }
     }
 
     /**
-     * Render a character using console characters.
+     * Shift console rows.
+     */
+    private static void shift_rows()
+    {
+        /* Shift up page 0 */
+        Fb.copy_rect(fb_x(0u, 0u), fb_y(1u),
+                m_width * Kfont.advance, (m_height - 1u) * Kfont.line_height,
+                fb_x(0u, 0u), fb_y(0u));
+        /* Copy page 1 first row to page 0 last row. */
+        Fb.copy_rect(fb_x(1u, 0u), fb_y(0u),
+                m_width * Kfont.advance, Kfont.line_height,
+                fb_x(0u, 0u), fb_y(m_height - 1u));
+        /* Shift up page 1 */
+        Fb.copy_rect(fb_x(1u, 0u), fb_y(1u),
+                m_width * Kfont.advance, (m_height - 1u) * Kfont.line_height,
+                fb_x(1u, 0u), fb_y(0u));
+        /* Erase page 1 last row. */
+        Fb.rect(fb_x(1u, 0u), fb_y(m_height - 1u),
+                m_width * Kfont.advance, Kfont.line_height, 0u);
+    }
+
+    /**
+     * Render a character.
      *
      * @param x X position.
      * @param y Y position.
      * @param ch Character to render.
      */
     private static void render_char(size_t x, size_t y, char ch)
-    {
-        render_char_fb(fb_x(x), fb_y(y), ch);
-    }
-
-    /**
-     * Render a character using framebuffer coordinates.
-     *
-     * @param x X position.
-     * @param y Y position.
-     * @param ch Character to render.
-     */
-    private static void render_char_fb(size_t x, size_t y, char ch)
     {
         const(CharInfo) * ci = &Kfont.chars[ch];
         Fb.blit_alpha_bitmap(x + ci.left, y + ci.top, ci.bitmap, ci.width, ci.height);
     }
 
     /**
-     * Get the framebuffer X coordinate corresponding to the console X position.
+     * Get the framebuffer X coordinate corresponding to the console page X position.
      */
-    private static size_t fb_x(size_t x)
+    private static size_t fb_x(size_t page, size_t x)
     {
-        return x * Kfont.advance;
+        return x * Kfont.advance + page * (m_width * Kfont.advance + 1);
     }
 
     /**
-     * Get the framebuffer Y coordinate corresponding to the console Y position.
+     * Get the framebuffer Y coordinate corresponding to the console page Y position.
      */
     private static size_t fb_y(size_t y)
     {
@@ -125,17 +146,18 @@ struct Console
     }
 
     /**
-     * Draw console header line.
+     * Draw console.
      */
-    private static draw_header()
+    private static draw()
     {
         static __gshared string header_text = "Welcome to HOS v" ~ VERSION ~ "!";
         Fb.rect(0u, Kfont.line_height, Fb.width, 1, BORDER_COLOR);
+        Fb.rect(m_width * Kfont.advance, Kfont.line_height, 1, Fb.height - Kfont.line_height, BORDER_COLOR);
         size_t x = 0;
         foreach (c; header_text)
         {
-            render_char_fb(fb_x(x), 0, c);
+            render_char(x, 0, c);
-            x++;
+            x += Kfont.advance;
         }
         update_header();
     }
@@ -151,7 +173,7 @@ struct Console
         Fb.rect(x, 0, Fb.width - x, Kfont.line_height, 0);
         Rtc.time rtc_time = Rtc.read_rtc_time();
         writef(function(ubyte ch) {
-                render_char_fb(x, 0, ch);
+                render_char(x, 0, ch);
                 x += Kfont.advance;
                 }, "%02u:%02u:%02u", rtc_time.hour, rtc_time.minute, rtc_time.second);
     }

src/hulk/fb.d

@@ -199,6 +199,34 @@ struct Fb
                 (m_stride * height));
     }
 
+    /**
+     * Copy a rectangle in the framebuffer.
+     *
+     * @param sx X coordinate of left of source rectangle.
+     * @param sy Y coordinate of top of source rectangle.
+     * @param width Width of rectangle to copy.
+     * @param height Height of rectangle to copy.
+     * @param dx X coordinate of left of destination rectangle.
+     * @param dy Y coordinate of top of destination rectangle.
+     */
+    static void copy_rect(size_t sx, size_t sy, size_t width, size_t height,
+            size_t dx, size_t dy)
+    {
+        size_t dest_buffer_index = buffer_index(dx, dy);
+        size_t src_buffer_index = buffer_index(sx, sy);
+        for (size_t y = 0u; y < height; y++)
+        {
+            memcpy32(&m_buffer1[dest_buffer_index],
+                     &m_buffer1[src_buffer_index],
+                     width);
+            memcpy32(&m_device_buffer[dest_buffer_index],
+                     &m_buffer1[dest_buffer_index],
+                     width);
+            dest_buffer_index += m_stride;
+            src_buffer_index += m_stride;
+        }
+    }
+
     /**
      * Return the buffer index for the given X and Y coordinates.
      *