Improved console scrolling.

src/celengine/console.cpp

@@ -17,6 +17,12 @@
 using namespace std;
 
 
+static int pmod(int n, int m)
+{
+    return n >= 0 ? n % m : m - (-(n + 1) % m) - 1;
+}
+
+
 Console::Console(int _nRows, int _nColumns) :
     ostream(&sbuf),
     text(NULL),
@@ -25,8 +31,9 @@ Console::Console(int _nRows, int _nColumns) :
     row(0),
     column(0),
     windowRow(0),
-    windowWidth(1),
-    windowHeight(1),
+    windowHeight(10),
+    xscale(1),
+    yscale(1),
     font(NULL),
     autoScroll(true)
 {
@@ -49,7 +56,7 @@ void Console::begin()
     glMatrixMode(GL_PROJECTION);
     glPushMatrix();
     glLoadIdentity();
-    gluOrtho2D(0, windowWidth, 0, windowHeight);
+    gluOrtho2D(0, xscale, 0, yscale);
     glMatrixMode(GL_MODELVIEW);
     glPushMatrix();
     glLoadIdentity();
@@ -81,7 +88,8 @@ void Console::render(int rowHeight)
     glPushMatrix();
     for (int i = 0; i < rowHeight; i++)
     {
-        int r = (nRows - rowHeight + 1 + windowRow + i) % nRows;
+        //int r = (nRows - rowHeight + 1 + windowRow + i) % nRows;
+        int r = pmod(row + windowRow + i, nRows);
         for (int j = 0; j < nColumns; j++)
         {
             char ch = text[r * (nColumns + 1) + j];
@@ -99,10 +107,10 @@ void Console::render(int rowHeight)
 }
 
 
-void Console::setWindowSize(int w, int h)
+void Console::setScale(int w, int h)
 {
-    windowWidth = w;
-    windowHeight = h;
+    xscale = w;
+    yscale = h;
 }
 
 
@@ -125,7 +133,7 @@ void Console::newline()
     column = 0;
 
     if (autoScroll)
-        windowRow = row;
+        windowRow = -(windowHeight - 1);
 }
 
 
@@ -192,6 +200,12 @@ void Console::setWindowRow(int _row)
 }
 
 
+void Console::setWindowHeight(int _height)
+{
+    windowHeight = _height;
+}
+
+
 int Console::getWidth() const
 {
     return nColumns;

src/celengine/console.h

@@ -43,7 +43,7 @@ class Console : public std::ostream
     void end();
     void render(int rowHeight);
 
-    void setWindowSize(int, int);
+    void setScale(int, int);
     void setFont(TextureFont*);
 
     void print(char);
@@ -57,6 +57,7 @@ class Console : public std::ostream
     int getColumn() const;
     int getWindowRow() const;
     void setWindowRow(int);
+    void setWindowHeight(int);
 
     int getHeight() const;
     int getWidth() const;
@@ -70,8 +71,10 @@ class Console : public std::ostream
 
     int windowRow;
 
-    int windowWidth;
     int windowHeight;
+
+    int xscale;
+    int yscale;
     TextureFont* font;
 
     ConsoleStreamBuf sbuf;

src/celestia/celestiacore.cpp

@@ -316,6 +316,7 @@ CelestiaCore::CelestiaCore() :
 
     clog.rdbuf(console.rdbuf());
     cerr.rdbuf(console.rdbuf());
+    console.setWindowHeight(ConsolePageRows);
 }
 
 CelestiaCore::~CelestiaCore()
@@ -848,23 +849,22 @@ void CelestiaCore::joystickButton(int button, bool down)
 
 static void scrollConsole(Console& con, int lines)
 {
-    int currentRow = con.getWindowRow();
     int topRow = con.getWindowRow();
     int height = con.getHeight();
 
     if (lines < 0)
     {
-        if ((topRow <= currentRow) != (topRow + lines <= currentRow))
-            console.setWindowRow(currentRow);
+        if (topRow + lines > -height)
+            console.setWindowRow(topRow + lines);
         else
-            console.setWindowRow((topRow + lines) % height);
+            console.setWindowRow(-(height - 1));
     }
     else
     {
-        if ((topRow < currentRow) != (topRow + lines < currentRow))
-            console.setWindowRow(currentRow);
+        if (topRow + lines <= -ConsolePageRows)
+            console.setWindowRow(topRow + lines);
         else
-            console.setWindowRow((topRow + lines) % height);
+            console.setWindowRow(-(ConsolePageRows - 1));
     }
 }
 
@@ -2033,7 +2033,7 @@ void CelestiaCore::resize(GLsizei w, GLsizei h)
         renderer->resize(w, h);
     if (overlay != NULL)
         overlay->setWindowSize(w, h);
-    console.setWindowSize(w, h);
+    console.setScale(w, h);
     width = w;
     height = h;