DONE:

- Removed usage of gdk_gl_font_use_pango_font() which is no longer in
  GtkGLExt Git.  Radiant now compiles on Linux From Scratch using current
  versions of software.
- As a side effect to the above, font inconsistency issues (like really
  large intermittent font in GL views) are gone.  Font looks better too.
- Changing algorithm for labeling grid view to be more robust.  Uses new
  functions gtk_glwidget_font_ascent() and gtk_glwidget_font_descent(),	and
  uses locally defined "cushion" variables.
- In xywindow.cpp, changing stepx and stepy based on 40 pixels, not 32.
  When coordinate numbers are very large the labels get too cluttered.
- Added	calls to gtk_gl_init() and gdk_gl_init() in main().  This is
  recommended according	to the GtkGLExt	reference manual.
- Tested all changes on	Ubuntu 10.10 and Debian	5.0 (Lenny).
TODO:
- In glDrawPixels(), instead of using a 32 bit pixel with
  GL_UNSIGNED_INT_8_8_8_8, see if we can use an 8 bit variant where each
  byte defines opacity and the GL current color is used.  In other words, try
  to use the FT_Bitmap directly without conversion.
- Examine every other use of gtk_glwidget_print_string() and
  gtk_glwidget_print_char() to make sure the positions are determined
  accurately.
NOT TODO:
- Decided not to use glBitmap() with display lists because it would
  disallow pretty antialiased fonts.


git-svn-id: svn://svn.icculus.org/gtkradiant/GtkRadiant/trunk@335 8a3a26a2-13c4-0310-b231-cf6edde360e5

radiant/camwindow.cpp

@@ -62,8 +62,6 @@ void CamWnd::OnCreate ()
   if (!MakeCurrent ())
     Error ("glMakeCurrent failed");
 
-  gtk_glwidget_create_font (m_pWidget);
-
   // report OpenGL information
   Sys_Printf ("GL_VENDOR: %s\n", qglGetString (GL_VENDOR));
   Sys_Printf ("GL_RENDERER: %s\n", qglGetString (GL_RENDERER));

radiant/glwidget.cpp

@@ -33,6 +33,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "stdafx.h"
 
 #include <gtk/gtkgl.h>
+#include <pango/pangoft2.h>
 #include "glwidget.h"
 #include "qgl.h"
 
@@ -206,46 +207,228 @@ gboolean WINAPI gtk_glwidget_make_current (GtkWidget *widget)
   return gdk_gl_drawable_gl_begin (gldrawable, glcontext);
 }
 
-GLuint font_list_base;
-static gchar font_string[] = "courier 8";
-static gint font_height;
 
-void gtk_glwidget_create_font (GtkWidget *widget)
+// Think about rewriting this font stuff to use OpenGL display lists and bit maps.
+// Bit maps together with display lists may offer a performance increase, but
+// they would not allow antialiased fonts.
+static const char font_string[] = "Monospace";
+static const int font_height = 10;
+static int font_ascent = -1;
+static int font_descent = -1;
+static int y_offset_bitmap_render_pango_units = -1;
+static PangoContext *ft2_context = NULL;
+static int _debug_font_created = 0;
+
+
+// Units are pixels.  Returns a positive value [most likely].
+int gtk_glwidget_font_ascent()
 {
-  PangoFontDescription *font_desc;
-  PangoFont *font;
-  PangoFontMetrics *font_metrics;
-
-  font_list_base = qglGenLists (256);
-
-  font_desc = pango_font_description_from_string (font_string);
-
-  font = gdk_gl_font_use_pango_font (font_desc, 0, 256, font_list_base);
-
-  if(font != NULL)
-  {
-    font_metrics = pango_font_get_metrics (font, NULL);
-
-    font_height = pango_font_metrics_get_ascent (font_metrics) +
-                  pango_font_metrics_get_descent (font_metrics);
-    font_height = PANGO_PIXELS (font_height);
-
-    pango_font_metrics_unref (font_metrics);
+  if (!_debug_font_created) {
+    Error("Programming error: gtk_glwidget_font_ascent() called but font does not exist; "
+          "you should have called gtk_glwidget_create_font() first");
   }
 
-  pango_font_description_free (font_desc);
+  return font_ascent;
+}
+
+// Units are pixels.  Returns a positive value [most likely].
+int gtk_glwidget_font_descent()
+{
+  if (!_debug_font_created) {
+    Error("Programming error: gtk_glwidget_font_descent() called but font does not exist; "
+          "you should have called gtk_glwidget_create_font() first");
+  }
+
+  return font_descent;
+}
+
+void gtk_glwidget_create_font()
+{
+  PangoFontDescription *font_desc;
+  PangoLayout *layout;
+  PangoRectangle log_rect;
+  int font_ascent_pango_units;
+  int font_descent_pango_units;
+
+  if (_debug_font_created) {
+    Error("Programming error: gtk_glwidget_create_font() was already called; "
+          "you must call gtk_glwidget_destroy_font() before creating font again");
+  }
+  _debug_font_created = 1;
+
+  // This call is deprecated so we'll have to fix it sometime.
+  ft2_context = pango_ft2_get_context(72, 72);
+
+  font_desc = pango_font_description_from_string(font_string);
+  pango_font_description_set_size(font_desc, font_height * PANGO_SCALE);
+  pango_context_set_font_description(ft2_context, font_desc);
+  pango_font_description_free(font_desc);
+
+  layout = pango_layout_new(ft2_context);
+#if !PANGO_VERSION_CHECK(1,22,0)
+  PangoLayoutIter *iter;  
+  iter = pango_layout_get_iter(layout);
+  font_ascent_pango_units = pango_layout_iter_get_baseline(iter);
+  pango_layout_iter_free(iter);
+#else
+  font_ascent_pango_units = pango_layout_get_baseline(layout);
+#endif
+  pango_layout_get_extents(layout, NULL, &log_rect);
+  g_object_unref(G_OBJECT(layout));
+  font_descent_pango_units = log_rect.height - font_ascent_pango_units;
+
+  font_ascent = PANGO_PIXELS_CEIL(font_ascent_pango_units);
+  font_descent = PANGO_PIXELS_CEIL(font_descent_pango_units);
+  y_offset_bitmap_render_pango_units = (font_ascent * PANGO_SCALE) - font_ascent_pango_units;
+}
+
+void gtk_glwidget_destroy_font()
+{
+  if (!_debug_font_created) {
+    Error("Programming error: gtk_glwidget_destroy_font() called when font "
+          "does not exist");
+  }
+
+  font_ascent = -1;
+  font_descent = -1;
+  y_offset_bitmap_render_pango_units = -1;
+  g_object_unref(G_OBJECT(ft2_context));
+  _debug_font_created = 0;
 }
 
 
+// Renders the input text at the current location with the current color.
+// The X position of the current location is used to place the left edge of the text image,
+// where the text image bounds are defined as the logical extents of the line of text.
+// The Y position of the current location is used to place the bottom of the text image.
+// You should offset the Y position by the amount returned by gtk_glwidget_font_descent()
+// if you want to place the baseline of the text image at the current Y position.
+// Note: A problem with this function is that if the lower left corner of the text falls
+// just a hair outside of the viewport (meaning the current raster position is invalid),
+// then no text will be rendered.  The solution to this is a very hacky one.  You can search
+// Google for "glDrawPixels clipping".
 void gtk_glwidget_print_string(const char *s)
 {
-  qglListBase(font_list_base);
-  qglCallLists(strlen(s), GL_UNSIGNED_BYTE, (unsigned char *)s);
+  // Much of this code is copied from the font-pangoft2.c example that comes with GtkGLExt.
+
+  PangoLayout *layout;
+  PangoRectangle ink_rect;
+  PangoRectangle log_rect;
+  FT_Bitmap bitmap;
+  GLvoid *pixels;
+  guint32 *p;
+  GLfloat color[4];
+  guint32 rgb;
+  GLfloat alpha;
+  guint8 *row, *row_end;
+  int i;
+  GLint previous_unpack_alignment;
+  GLboolean previous_blend_enabled;
+  GLint previous_blend_src;
+  GLint previous_blend_dst;
+
+
+  if (!_debug_font_created) {
+    Error("Programming error: gtk_glwidget_print_string() called but font does not exist; "
+          "you should have called gtk_glwidget_create_font() first");
+  }
+
+  layout = pango_layout_new(ft2_context);
+  pango_layout_set_width(layout, -1); // -1 no wrapping.  All text on one line.
+  pango_layout_set_text(layout, s, -1); // -1 null-terminated string.
+  pango_layout_get_extents(layout, &ink_rect, &log_rect);
+
+  if (log_rect.width > 0 && log_rect.height > 0) {
+    bitmap.rows = font_ascent + font_descent;
+    bitmap.width = PANGO_PIXELS_CEIL(log_rect.width);
+    bitmap.pitch = bitmap.width;
+    bitmap.buffer = g_malloc(bitmap.rows * bitmap.width);
+    bitmap.num_grays = 0xff;
+    bitmap.pixel_mode = FT_PIXEL_MODE_GRAY;
+    memset(bitmap.buffer, 0, bitmap.rows * bitmap.width);
+    pango_ft2_render_layout_subpixel(&bitmap, layout, -log_rect.x,
+                                     y_offset_bitmap_render_pango_units);
+
+    pixels = g_malloc(bitmap.rows * bitmap.width * 4);
+    p = (guint32 *) pixels;
+    qglGetFloatv(GL_CURRENT_COLOR, color);
+#if !defined(GL_VERSION_1_2) && G_BYTE_ORDER == G_LITTLE_ENDIAN
+    rgb =
+      (((guint32) (color[0] * 255.0)) << 0) |
+      (((guint32) (color[1] * 255.0)) << 8) |
+      (((guint32) (color[2] * 255.0)) << 16);
+#else
+    rgb =
+      (((guint32) (color[0] * 255.0)) << 24) |
+      (((guint32) (color[1] * 255.0)) << 16) |
+      (((guint32) (color[2] * 255.0)) << 8);
+#endif
+    alpha = color[3];
+
+    row = bitmap.buffer + bitmap.rows * bitmap.width; // Past the end.
+    row_end = bitmap.buffer; // Beginning.
+
+    if (alpha == 1.0) {
+      do {
+        row -= bitmap.width;
+        for (i = 0; i < bitmap.width; i++) {
+#if !defined(GL_VERSION_1_2) && G_BYTE_ORDER == G_LITTLE_ENDIAN
+          *p++ = rgb | (((guint32) row[i]) << 24);
+#else
+          *p++ = rgb | ((guint32) row[i]);
+#endif
+        }
+      } while (row != row_end);
+    }
+
+    else { // Translucent.  Much less efficient, so try to avoid.
+      do {
+        row -= bitmap.width;
+        for (i = 0; i < bitmap.width; i++) {
+#if !defined(GL_VERSION_1_2) && G_BYTE_ORDER == G_LITTLE_ENDIAN
+          *p++ = rgb | (((guint32) (alpha * row[i])) << 24);
+#else
+          *p++ = rgb | ((guint32) (alpha * row[i]));
+#endif
+        }
+      } while (row != row_end);
+    }
+
+    // Save state.  I didn't see any OpenGL push/pop operations for these.
+    // Question: Is saving/restoring this state necessary?
+    qglGetIntegerv(GL_UNPACK_ALIGNMENT, &previous_unpack_alignment);
+    previous_blend_enabled = qglIsEnabled(GL_BLEND);
+    qglGetIntegerv(GL_BLEND_SRC, &previous_blend_src);
+    qglGetIntegerv(GL_BLEND_DST, &previous_blend_dst);
+
+    qglPixelStorei(GL_UNPACK_ALIGNMENT, 4);
+    qglEnable(GL_BLEND);
+    qglBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+#if !defined(GL_VERSION_1_2)
+    qglDrawPixels(bitmap.width, bitmap.rows,
+                  GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+#else
+    qglDrawPixels(bitmap.width, bitmap.rows,
+                  GL_RGBA, GL_UNSIGNED_INT_8_8_8_8, pixels);
+#endif
+
+    // Restore state in reverse order of how we set it.
+    qglBlendFunc(previous_blend_src, previous_blend_dst);
+    if (!previous_blend_enabled) { qglDisable(GL_BLEND); }
+    qglPixelStorei(GL_UNPACK_ALIGNMENT, previous_unpack_alignment);
+
+    g_free(bitmap.buffer);
+    g_free(pixels);
+  }
+
+  g_object_unref(G_OBJECT(layout));
 }
 
 void gtk_glwidget_print_char(char s)
 {
-  qglListBase(font_list_base);
-  qglCallLists(1, GL_UNSIGNED_BYTE, (unsigned char *) &s);
+  char str[2];
+  str[0] = s;
+  str[1] = '\0';
+  gtk_glwidget_print_string(str);
 }
-

radiant/glwidget.h

@@ -36,10 +36,11 @@ void       WINAPI gtk_glwidget_swap_buffers (GtkWidget *widget);
 gboolean   WINAPI gtk_glwidget_make_current (GtkWidget *widget);
 void       WINAPI gtk_glwidget_destroy_context (GtkWidget *widget);
 void       WINAPI gtk_glwidget_create_context (GtkWidget *widget);
-void       gtk_glwidget_create_font (GtkWidget *widget);
-
+void       gtk_glwidget_create_font();
+int        gtk_glwidget_font_ascent();
+int        gtk_glwidget_font_descent();
 void       gtk_glwidget_print_string(const char *s);
 void       gtk_glwidget_print_char(char s);
-
+void       gtk_glwidget_destroy_font();
 
 #endif /* _GLWIDGET_H_ */

radiant/main.cpp

@@ -34,6 +34,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #endif
 
 #include <gtk/gtk.h>
+#include <gtk/gtkgl.h>
 #include <glib/gi18n.h>
 #include "stdafx.h"
 #include <assert.h>
@@ -44,6 +45,7 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 
 #include "watchbsp.h"
 #include "filters.h"
+#include "glwidget.h"
 
 bool g_bBuildList = false;
 int g_argc;
@@ -503,6 +505,11 @@ int main( int argc, char* argv[] ) {
 //  gtk_disable_setlocale();
 
   gtk_init(&argc, &argv);
+  gtk_gl_init(&argc, &argv);
+  gdk_gl_init(&argc, &argv);
+
+  // TODO: Find a better place to call this.
+  gtk_glwidget_create_font();
 
   if ((ptr = getenv ("Q3R_LIBGL")) != NULL)
     libgl = ptr;

radiant/mainframe.cpp

@@ -3227,9 +3227,6 @@ void MainFrame::OnSleep()
 */
     Sys_Printf("Done.\n");
 
-    // bring back the GL font
-    gtk_glwidget_create_font (m_pCamWnd->GetWidget ());
-
     g_bScreenUpdates = true;
 
     Sys_Printf("Dispatching wake msg...");

radiant/xywindow.cpp

@@ -2232,9 +2232,9 @@ void XYWnd::XY_DrawGrid()
   while ((step * m_fScale) < 4.0f) // make sure major grid spacing is at least 4 pixels on the screen
     step *= 8;
   //Sys_Printf("step after: %i\n", step);
-  while ((stepx * m_fScale) < 32.0f) // text step x must be at least 32
+  while ((stepx * m_fScale) < 40.0f) // text step x must be at least 40 pixels
     stepx *= 2;
-  while ((stepy * m_fScale) < 32.0f) // text step y must be at least 32
+  while ((stepy * m_fScale) < 40.0f) // text step y must be at least 40 pixels
     stepy *= 2;
 
   qglDisable(GL_TEXTURE_2D);
@@ -2334,19 +2334,41 @@ void XYWnd::XY_DrawGrid()
   if ( g_qeglobals.d_savedinfo.show_coordinates)
   {
     qglColor3fv(g_qeglobals.d_savedinfo.colors[COLOR_GRIDTEXT]);
-		float offx = m_vOrigin[nDim2] + h - 6 / m_fScale, offy = m_vOrigin[nDim1] - w + 1 / m_fScale;
-		for (x=xb-((int)xb)%stepx; x<=xe ; x+=stepx)
-		{
-			qglRasterPos2f (x, offx);
-			sprintf (text, "%i",(int)x);
-			gtk_glwidget_print_string(text);
-		}
-		for (y=yb-((int)yb)%stepy; y<=ye ; y+=stepy)
-		{
-			qglRasterPos2f (offy, y);
-			sprintf (text, "%i",(int)y);
-			gtk_glwidget_print_string(text);
-		}
+
+    // Pixels between top of label for vertical grid line and top of grid view window.
+    // Note: There is currently a bug where the top few pixels of the grid view are hidden
+    // under the border.  So you should add about 5 to the desired value here.  However,
+    // the font ascent reaches higher than all digits, so you can subtract a few from the final
+    // number.
+    const int pixelsTopCushion = 4;
+
+    // Pixels between left of label and
+    //   - left of grid view window (for horizontal grid line label) or
+    //   - drawn vertical grid line (for vertical grid line label).
+    const int pixelsLeftCushion = 2; // IMPORTANT!  Must be at least 1 otherwise labels might not be drawn
+                                     // because the origin of the text might be off screen due to rounding.
+
+    // Pixels between baseline of horizontal grid line label and drawn horizontal grid line.
+    const int pixelsButtomCushion = 2;
+
+    float yPosLabelsTop = m_vOrigin[nDim2] + h - (gtk_glwidget_font_ascent() + pixelsTopCushion) / m_fScale;
+    float xPosLabelsLeft = m_vOrigin[nDim1] - w + pixelsLeftCushion / m_fScale;
+    float leftCushion = pixelsLeftCushion / m_fScale;
+    float bottomOffset = (pixelsButtomCushion - gtk_glwidget_font_descent()) / m_fScale;
+
+    // This renders the numbers along varying X on top of the grid view (labels vertical grid lines).
+    for (x = xb - ((int) xb) % stepx; x <= xe; x += stepx) {
+      qglRasterPos2f(x + leftCushion, yPosLabelsTop);
+      sprintf(text, "%i", (int) x);
+      gtk_glwidget_print_string(text);
+    }
+
+    // This renders the numbers along varying Y on the left of the grid view (labels horizontal grid lines).
+    for (y = yb - ((int) yb) % stepy; y <= ye; y += stepy) {
+      qglRasterPos2f(xPosLabelsLeft, y + bottomOffset);
+      sprintf(text, "%i", (int) y);
+      gtk_glwidget_print_string(text);
+    }
 
     if (Active())
       qglColor3fv(g_qeglobals.d_savedinfo.colors[COLOR_VIEWNAME]);