Adding upstream version 2.10.34.upstream/2.10.34upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 745 insertions, 0 deletions

diff --git a/plug-ins/map-object/map-object-preview.c b/plug-ins/map-object/map-object-preview.c
new file mode 100644
index 0000000..afc29b4
--- /dev/null
+++ b/plug-ins/map-object/map-object-preview.c
@@ -0,0 +1,745 @@
+/*************************************************/
+/* Compute a preview image and preview wireframe */
+/*************************************************/
+
+#include "config.h"
+
+#include <gtk/gtk.h>
+
+#include <libgimp/gimp.h>
+#include <libgimp/gimpui.h>
+
+#include "map-object-main.h"
+#include "map-object-ui.h"
+#include "map-object-image.h"
+#include "map-object-apply.h"
+#include "map-object-shade.h"
+#include "map-object-preview.h"
+
+
+gdouble mat[3][4];
+gint    lightx, lighty;
+
+/* Protos */
+/* ====== */
+
+static void compute_preview         (gint x,
+                                     gint y,
+                                     gint w,
+                                     gint h,
+                                     gint pw,
+                                     gint ph);
+static void draw_light_marker       (cairo_t *cr,
+                                     gint xpos,
+                                     gint ypos);
+static void draw_line               (cairo_t    *cr,
+                                     gint        startx,
+                                     gint        starty,
+                                     gint        pw,
+                                     gint        ph,
+                                     gdouble     cx1,
+                                     gdouble     cy1,
+                                     gdouble     cx2,
+                                     gdouble     cy2,
+                                     GimpVector3 a,
+                                     GimpVector3 b);
+static void draw_wireframe          (cairo_t *cr,
+                                     gint startx,
+                                     gint starty,
+                                     gint pw,
+                                     gint ph);
+static void draw_preview_wireframe  (cairo_t *cr);
+static void draw_wireframe_plane    (cairo_t *cr,
+                                     gint        startx,
+                                     gint        starty,
+                                     gint        pw,
+                                     gint        ph);
+static void draw_wireframe_sphere   (cairo_t *cr,
+                                     gint        startx,
+                                     gint        starty,
+                                     gint        pw,
+                                     gint        ph);
+static void draw_wireframe_box      (cairo_t *cr,
+                                     gint        startx,
+                                     gint        starty,
+                                     gint        pw,
+                                     gint        ph);
+static void draw_wireframe_cylinder (cairo_t *cr,
+                                     gint        startx,
+                                     gint        starty,
+                                     gint        pw,
+                                     gint        ph);
+
+/**************************************************************/
+/* Computes a preview of the rectangle starting at (x,y) with */
+/* dimensions (w,h), placing the result in preview_RGB_data.  */
+/**************************************************************/
+
+static void
+compute_preview (gint x,
+                 gint y,
+                 gint w,
+                 gint h,
+                 gint pw,
+                 gint ph)
+{
+  gdouble      xpostab[PREVIEW_WIDTH];
+  gdouble      ypostab[PREVIEW_HEIGHT];
+  gdouble      realw;
+  gdouble      realh;
+  GimpVector3  p1, p2;
+  GimpRGB      color;
+  GimpRGB      lightcheck, darkcheck;
+  gint         xcnt, ycnt, f1, f2;
+  guchar       r, g, b;
+  glong        index = 0;
+
+  init_compute ();
+
+  if (! preview_surface)
+    return;
+
+  p1 = int_to_pos (x, y);
+  p2 = int_to_pos (x + w, y + h);
+
+  /* First, compute the linear mapping (x,y,x+w,y+h) to (0,0,pw,ph) */
+  /* ============================================================== */
+
+  realw = (p2.x - p1.x);
+  realh = (p2.y - p1.y);
+
+  for (xcnt = 0; xcnt < pw; xcnt++)
+    xpostab[xcnt] = p1.x + realw * ((gdouble) xcnt / (gdouble) pw);
+
+  for (ycnt = 0; ycnt < ph; ycnt++)
+    ypostab[ycnt] = p1.y + realh * ((gdouble) ycnt / (gdouble) ph);
+
+  /* Compute preview using the offset tables */
+  /* ======================================= */
+
+  if (mapvals.transparent_background == TRUE)
+    {
+      gimp_rgba_set (&background, 0.0, 0.0, 0.0, 0.0);
+    }
+  else
+    {
+      gimp_context_get_background (&background);
+      gimp_rgb_set_alpha (&background, 1.0);
+    }
+
+  gimp_rgba_set (&lightcheck,
+                 GIMP_CHECK_LIGHT, GIMP_CHECK_LIGHT, GIMP_CHECK_LIGHT, 1.0);
+  gimp_rgba_set (&darkcheck,
+                 GIMP_CHECK_DARK, GIMP_CHECK_DARK, GIMP_CHECK_DARK, 1.0);
+  gimp_vector3_set (&p2, -1.0, -1.0, 0.0);
+
+  cairo_surface_flush (preview_surface);
+
+  for (ycnt = 0; ycnt < ph; ycnt++)
+    {
+      index = ycnt * preview_rgb_stride;
+      for (xcnt = 0; xcnt < pw; xcnt++)
+        {
+          p1.x = xpostab[xcnt];
+          p1.y = ypostab[ycnt];
+
+          p2 = p1;
+          color = (* get_ray_color) (&p1);
+
+          if (color.a < 1.0)
+            {
+              f1 = ((xcnt % 32) < 16);
+              f2 = ((ycnt % 32) < 16);
+              f1 = f1 ^ f2;
+
+              if (f1)
+                {
+                  if (color.a == 0.0)
+                    color = lightcheck;
+                  else
+                    gimp_rgb_composite (&color, &lightcheck,
+                                        GIMP_RGB_COMPOSITE_BEHIND);
+                 }
+              else
+                {
+                  if (color.a == 0.0)
+                    color = darkcheck;
+                  else
+                    gimp_rgb_composite (&color, &darkcheck,
+                                        GIMP_RGB_COMPOSITE_BEHIND);
+                }
+            }
+
+          gimp_rgb_get_uchar (&color, &r, &g, &b);
+          GIMP_CAIRO_RGB24_SET_PIXEL((preview_rgb_data + index), r, g, b);
+          index += 4;
+        }
+    }
+  cairo_surface_mark_dirty (preview_surface);
+}
+
+/*************************************************/
+/* Check if the given position is within the     */
+/* light marker. Return TRUE if so, FALSE if not */
+/*************************************************/
+
+gint
+check_light_hit (gint xpos,
+                 gint ypos)
+{
+  gdouble dx, dy, r;
+
+  if (mapvals.lightsource.type == POINT_LIGHT)
+    {
+      dx = (gdouble) lightx - xpos;
+      dy = (gdouble) lighty - ypos;
+      r  = sqrt (dx * dx + dy * dy) + 0.5;
+
+      if ((gint) r > 7)
+        return FALSE;
+      else
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
+/****************************************/
+/* Draw a marker to show light position */
+/****************************************/
+
+static void
+draw_light_marker (cairo_t *cr,
+                   gint xpos,
+                   gint ypos)
+{
+  GdkColor color;
+
+  if (mapvals.lightsource.type != POINT_LIGHT)
+    return;
+
+  cairo_set_line_width (cr, 1.0);
+
+  color.red   = 0x0;
+  color.green = 0x4000;
+  color.blue  = 0xFFFF;
+  gdk_cairo_set_source_color (cr, &color);
+
+  lightx = xpos;
+  lighty = ypos;
+
+  cairo_arc (cr, lightx, lighty, 7, 0, 2 * G_PI);
+  cairo_fill (cr);
+}
+
+static void
+draw_lights (cairo_t *cr,
+             gint startx,
+             gint starty,
+             gint pw,
+             gint ph)
+{
+  gdouble dxpos, dypos;
+  gint    xpos, ypos;
+
+  gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                        &dxpos, &dypos, &mapvals.viewpoint,
+                        &mapvals.lightsource.position);
+  xpos = RINT (dxpos);
+  ypos = RINT (dypos);
+
+  if (xpos >= 0 && xpos <= PREVIEW_WIDTH &&
+      ypos >= 0 && ypos <= PREVIEW_HEIGHT)
+    {
+      draw_light_marker (cr, xpos, ypos);
+    }
+}
+
+/*************************************************/
+/* Update light position given new screen coords */
+/*************************************************/
+
+void
+update_light (gint xpos,
+              gint ypos)
+{
+  gint    startx, starty, pw, ph;
+
+  pw     = PREVIEW_WIDTH * mapvals.zoom;
+  ph     = PREVIEW_HEIGHT * mapvals.zoom;
+  startx = (PREVIEW_WIDTH  - pw) / 2;
+  starty = (PREVIEW_HEIGHT - ph) / 2;
+
+  gimp_vector_2d_to_3d (startx, starty, pw, ph, xpos, ypos,
+                        &mapvals.viewpoint, &mapvals.lightsource.position);
+
+  gtk_widget_queue_draw (previewarea);
+}
+
+/**************************/
+/* Compute preview image. */
+/**************************/
+
+void
+compute_preview_image (void)
+{
+  GdkDisplay *display = gtk_widget_get_display (previewarea);
+  GdkCursor  *cursor;
+  gint        pw, ph;
+
+  pw = PREVIEW_WIDTH * mapvals.zoom;
+  ph = PREVIEW_HEIGHT * mapvals.zoom;
+
+  cursor = gdk_cursor_new_for_display (display, GDK_WATCH);
+  gdk_window_set_cursor (gtk_widget_get_window (previewarea), cursor);
+  gdk_cursor_unref (cursor);
+
+  compute_preview (0, 0, width - 1, height - 1, pw, ph);
+
+  cursor = gdk_cursor_new_for_display (display, GDK_HAND2);
+  gdk_window_set_cursor(gtk_widget_get_window (previewarea), cursor);
+  gdk_cursor_unref (cursor);
+}
+
+gboolean
+preview_expose (GtkWidget      *widget,
+                GdkEventExpose *eevent)
+{
+  gint startx, starty, pw, ph;
+  cairo_t *cr;
+
+  cr = gdk_cairo_create (eevent->window);
+
+  pw = PREVIEW_WIDTH * mapvals.zoom;
+  ph = PREVIEW_HEIGHT * mapvals.zoom;
+  startx = (PREVIEW_WIDTH - pw) / 2;
+  starty = (PREVIEW_HEIGHT - ph) / 2;
+
+  cairo_set_source_surface (cr, preview_surface, startx, starty);
+  cairo_rectangle (cr, startx, starty, pw, ph);
+  cairo_clip (cr);
+
+  cairo_paint (cr);
+
+  cairo_reset_clip (cr);
+
+  if (mapvals.showgrid)
+    draw_preview_wireframe (cr);
+
+  cairo_reset_clip (cr);
+  draw_lights (cr, startx, starty, pw, ph);
+
+  cairo_destroy (cr);
+
+  return FALSE;
+}
+
+/**************************/
+/* Draw preview wireframe */
+/**************************/
+
+void
+draw_preview_wireframe (cairo_t *cr)
+{
+  gint      startx, starty, pw, ph;
+
+  pw     = PREVIEW_WIDTH  * mapvals.zoom;
+  ph     = PREVIEW_HEIGHT * mapvals.zoom;
+  startx = (PREVIEW_WIDTH  - pw) / 2;
+  starty = (PREVIEW_HEIGHT - ph) / 2;
+
+  draw_wireframe (cr, startx, starty, pw, ph);
+}
+
+/****************************/
+/* Draw a wireframe preview */
+/****************************/
+
+void
+draw_wireframe (cairo_t *cr,
+                gint startx,
+                gint starty,
+                gint pw,
+                gint ph)
+{
+  cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
+  switch (mapvals.maptype)
+    {
+    case MAP_PLANE:
+      draw_wireframe_plane (cr, startx, starty, pw, ph);
+      break;
+    case MAP_SPHERE:
+      draw_wireframe_sphere (cr, startx, starty, pw, ph);
+      break;
+    case MAP_BOX:
+      draw_wireframe_box (cr, startx, starty, pw, ph);
+      break;
+    case MAP_CYLINDER:
+      draw_wireframe_cylinder (cr, startx, starty, pw, ph);
+      break;
+    }
+}
+
+static void
+draw_wireframe_plane (cairo_t *cr,
+                      gint startx,
+                      gint starty,
+                      gint pw,
+                      gint ph)
+{
+  GimpVector3 v1, v2, a, b, c, d, dir1, dir2;
+  gint        cnt;
+  gdouble     x1, y1, x2, y2, fac;
+
+  cairo_rectangle (cr, startx, starty, pw, ph);
+  cairo_clip (cr);
+
+  /* Find rotated box corners */
+  /* ======================== */
+
+  gimp_vector3_set (&v1, 0.5, 0.0, 0.0);
+  gimp_vector3_set (&v2, 0.0, 0.5, 0.0);
+
+  gimp_vector3_rotate (&v1,
+                       gimp_deg_to_rad (mapvals.alpha),
+                       gimp_deg_to_rad (mapvals.beta),
+                       gimp_deg_to_rad (mapvals.gamma));
+
+  gimp_vector3_rotate (&v2,
+                       gimp_deg_to_rad (mapvals.alpha),
+                       gimp_deg_to_rad (mapvals.beta),
+                       gimp_deg_to_rad (mapvals.gamma));
+
+  dir1 = v1; gimp_vector3_normalize (&dir1);
+  dir2 = v2; gimp_vector3_normalize (&dir2);
+
+  fac = 1.0 / (gdouble) WIRESIZE;
+
+  gimp_vector3_mul (&dir1, fac);
+  gimp_vector3_mul (&dir2, fac);
+
+  gimp_vector3_add (&a, &mapvals.position, &v1);
+  gimp_vector3_sub (&b, &a, &v2);
+  gimp_vector3_add (&a, &a, &v2);
+  gimp_vector3_sub (&d, &mapvals.position, &v1);
+  gimp_vector3_sub (&d, &d, &v2);
+
+  c = b;
+
+  for (cnt = 0; cnt <= WIRESIZE; cnt++)
+    {
+      gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                            &x1, &y1, &mapvals.viewpoint, &a);
+      gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                            &x2, &y2, &mapvals.viewpoint, &b);
+
+      cairo_move_to (cr, RINT (x1) + 0.5, RINT (y1) + 0.5);
+      cairo_line_to (cr, RINT (x2) + 0.5, RINT (y2) + 0.5);
+
+      gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                            &x1, &y1, &mapvals.viewpoint, &c);
+      gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                            &x2, &y2, &mapvals.viewpoint, &d);
+
+      cairo_move_to (cr, RINT (x1) + 0.5, RINT (y1) + 0.5);
+      cairo_line_to (cr, RINT (x2) + 0.5, RINT (y2) + 0.5);
+
+      gimp_vector3_sub (&a, &a, &dir1);
+      gimp_vector3_sub (&b, &b, &dir1);
+      gimp_vector3_add (&c, &c, &dir2);
+      gimp_vector3_add (&d, &d, &dir2);
+    }
+
+  cairo_set_line_width (cr, 3.0);
+  cairo_stroke_preserve (cr);
+  cairo_set_line_width (cr, 1.0);
+  cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
+  cairo_stroke (cr);
+}
+
+static void
+draw_wireframe_sphere (cairo_t *cr,
+                       gint startx,
+                       gint starty,
+                       gint pw,
+                       gint ph)
+{
+  GimpVector3 p[2 * (WIRESIZE + 5)];
+  gint        cnt, cnt2;
+  gdouble     x1, y1, x2, y2, twopifac;
+
+  cairo_rectangle (cr, startx, starty, pw, ph);
+  cairo_clip (cr);
+
+  /* Compute wireframe points */
+  /* ======================== */
+
+  twopifac = (2.0 * G_PI) / WIRESIZE;
+
+  for (cnt = 0; cnt < WIRESIZE; cnt++)
+    {
+      p[cnt].x = mapvals.radius * cos ((gdouble) cnt * twopifac);
+      p[cnt].y = 0.0;
+      p[cnt].z = mapvals.radius * sin ((gdouble) cnt * twopifac);
+      gimp_vector3_rotate (&p[cnt],
+                           gimp_deg_to_rad (mapvals.alpha),
+                           gimp_deg_to_rad (mapvals.beta),
+                           gimp_deg_to_rad (mapvals.gamma));
+      gimp_vector3_add (&p[cnt], &p[cnt], &mapvals.position);
+    }
+
+  p[cnt] = p[0];
+
+  for (cnt = WIRESIZE + 1; cnt < 2 * WIRESIZE + 1; cnt++)
+    {
+      p[cnt].x = mapvals.radius * cos ((gdouble) (cnt-(WIRESIZE+1))*twopifac);
+      p[cnt].y = mapvals.radius * sin ((gdouble) (cnt-(WIRESIZE+1))*twopifac);
+      p[cnt].z = 0.0;
+      gimp_vector3_rotate (&p[cnt],
+                           gimp_deg_to_rad (mapvals.alpha),
+                           gimp_deg_to_rad (mapvals.beta),
+                           gimp_deg_to_rad (mapvals.gamma));
+      gimp_vector3_add (&p[cnt], &p[cnt], &mapvals.position);
+    }
+
+  p[cnt] = p[WIRESIZE+1];
+  cnt++;
+  cnt2 = cnt;
+
+  /* Find rotated axis */
+  /* ================= */
+
+  gimp_vector3_set (&p[cnt], 0.0, -0.35, 0.0);
+  gimp_vector3_rotate (&p[cnt],
+                       gimp_deg_to_rad (mapvals.alpha),
+                       gimp_deg_to_rad (mapvals.beta),
+                       gimp_deg_to_rad (mapvals.gamma));
+  p[cnt+1] = mapvals.position;
+
+  gimp_vector3_set (&p[cnt+2], 0.0, 0.0, -0.35);
+  gimp_vector3_rotate (&p[cnt+2],
+                       gimp_deg_to_rad (mapvals.alpha),
+                       gimp_deg_to_rad (mapvals.beta),
+                       gimp_deg_to_rad (mapvals.gamma));
+  p[cnt+3] = mapvals.position;
+
+  p[cnt + 4] = p[cnt];
+  gimp_vector3_mul (&p[cnt + 4], -1.0);
+  p[cnt + 5] = p[cnt + 1];
+
+  gimp_vector3_add (&p[cnt],     &p[cnt],     &mapvals.position);
+  gimp_vector3_add (&p[cnt + 2], &p[cnt + 2], &mapvals.position);
+  gimp_vector3_add (&p[cnt + 4], &p[cnt + 4], &mapvals.position);
+
+  /* Draw the circles (equator and zero meridian) */
+  /* ============================================ */
+
+  for (cnt = 0; cnt < cnt2 - 1; cnt++)
+    {
+      if (p[cnt].z > mapvals.position.z && p[cnt + 1].z > mapvals.position.z)
+        {
+          gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                                &x1, &y1, &mapvals.viewpoint, &p[cnt]);
+          gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                                &x2, &y2, &mapvals.viewpoint, &p[cnt + 1]);
+
+          cairo_move_to (cr, (gint) (x1 + 0.5) + 0.5, (gint) (y1 + 0.5) + 0.5);
+          cairo_line_to (cr, (gint) (x2 + 0.5) + 0.5, (gint) (y2 + 0.5) + 0.5);
+        }
+    }
+
+  /* Draw the axis (pole to pole and center to zero meridian) */
+  /* ======================================================== */
+
+  for (cnt = 0; cnt < 3; cnt++)
+    {
+      gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                            &x1, &y1, &mapvals.viewpoint, &p[cnt2]);
+      gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                            &x2, &y2, &mapvals.viewpoint, &p[cnt2 + 1]);
+
+      cairo_move_to (cr, RINT (x1) + 0.5, RINT (y1) + 0.5);
+      cairo_line_to (cr, RINT (x2) + 0.5, RINT (y2) + 0.5);
+
+      cnt2 += 2;
+    }
+
+  cairo_set_line_width (cr, 3.0);
+  cairo_stroke_preserve (cr);
+  cairo_set_line_width (cr, 1.0);
+  cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
+  cairo_stroke (cr);
+}
+
+static void
+draw_line (cairo_t    *cr,
+           gint        startx,
+           gint        starty,
+           gint        pw,
+           gint        ph,
+           gdouble     cx1,
+           gdouble     cy1,
+           gdouble     cx2,
+           gdouble     cy2,
+           GimpVector3 a,
+           GimpVector3 b)
+{
+  gdouble x1, y1, x2, y2;
+
+  gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                        &x1, &y1, &mapvals.viewpoint, &a);
+  gimp_vector_3d_to_2d (startx, starty, pw, ph,
+                        &x2, &y2, &mapvals.viewpoint, &b);
+
+  cairo_move_to (cr, RINT (x1) + 0.5, RINT (y1) + 0.5);
+  cairo_line_to (cr, RINT (x2) + 0.5, RINT (y2) + 0.5);
+}
+
+static void
+draw_wireframe_box (cairo_t *cr,
+                    gint startx,
+                    gint starty,
+                    gint pw,
+                    gint ph)
+{
+  GimpVector3 p[8], tmp, scale;
+  gint        i;
+  gdouble     cx1, cy1, cx2, cy2;
+
+  cairo_rectangle (cr, startx, starty, pw, ph);
+  cairo_clip (cr);
+
+  /* Compute wireframe points */
+  /* ======================== */
+
+  init_compute ();
+
+  scale = mapvals.scale;
+  gimp_vector3_mul (&scale, 0.5);
+
+  gimp_vector3_set (&p[0], -scale.x, -scale.y, scale.z);
+  gimp_vector3_set (&p[1],  scale.x, -scale.y, scale.z);
+  gimp_vector3_set (&p[2],  scale.x,  scale.y, scale.z);
+  gimp_vector3_set (&p[3], -scale.x,  scale.y, scale.z);
+
+  gimp_vector3_set (&p[4], -scale.x, -scale.y, -scale.z);
+  gimp_vector3_set (&p[5],  scale.x, -scale.y, -scale.z);
+  gimp_vector3_set (&p[6],  scale.x,  scale.y, -scale.z);
+  gimp_vector3_set (&p[7], -scale.x,  scale.y, -scale.z);
+
+  /* Rotate and translate points */
+  /* =========================== */
+
+  for (i = 0; i < 8; i++)
+    {
+      vecmulmat (&tmp, &p[i], rotmat);
+      gimp_vector3_add (&p[i], &tmp, &mapvals.position);
+    }
+
+  /* Draw the box */
+  /* ============ */
+
+  cx1 = (gdouble) startx;
+  cy1 = (gdouble) starty;
+  cx2 = cx1 + (gdouble) pw;
+  cy2 = cy1 + (gdouble) ph;
+
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[0],p[1]);
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[1],p[2]);
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[2],p[3]);
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[3],p[0]);
+
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[4],p[5]);
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[5],p[6]);
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[6],p[7]);
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[7],p[4]);
+
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[0],p[4]);
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[1],p[5]);
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[2],p[6]);
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[3],p[7]);
+
+  cairo_set_line_width (cr, 3.0);
+  cairo_stroke_preserve (cr);
+  cairo_set_line_width (cr, 1.0);
+  cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
+  cairo_stroke (cr);
+}
+
+static void
+draw_wireframe_cylinder (cairo_t *cr,
+                         gint startx,
+                         gint starty,
+                         gint pw,
+                         gint ph)
+{
+  GimpVector3 p[2*8], a, axis, scale;
+  gint        i;
+  gdouble     cx1, cy1, cx2, cy2;
+  gfloat      m[16], l, angle;
+
+  cairo_rectangle (cr, startx, starty, pw, ph);
+  cairo_clip (cr);
+
+  /* Compute wireframe points */
+  /* ======================== */
+
+  init_compute ();
+
+  scale = mapvals.scale;
+  gimp_vector3_mul (&scale, 0.5);
+
+  l = mapvals.cylinder_length / 2.0;
+  angle = 0;
+
+  gimp_vector3_set (&axis, 0.0, 1.0, 0.0);
+
+  for (i = 0; i < 8; i++)
+    {
+      rotatemat (angle, &axis, m);
+
+      gimp_vector3_set (&a, mapvals.cylinder_radius, 0.0, 0.0);
+
+      vecmulmat (&p[i], &a, m);
+
+      p[i+8] = p[i];
+
+      p[i].y   += l;
+      p[i+8].y -= l;
+
+      angle += 360.0 / 8.0;
+    }
+
+  /* Rotate and translate points */
+  /* =========================== */
+
+  for (i = 0; i < 16; i++)
+    {
+      vecmulmat (&a, &p[i], rotmat);
+      gimp_vector3_add (&p[i], &a, &mapvals.position);
+    }
+
+  /* Draw the box */
+  /* ============ */
+
+  cx1 = (gdouble) startx;
+  cy1 = (gdouble) starty;
+  cx2 = cx1 + (gdouble) pw;
+  cy2 = cy1 + (gdouble) ph;
+
+  for (i = 0; i < 7; i++)
+    {
+      draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[i],p[i+1]);
+      draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[i+8],p[i+9]);
+      draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[i],p[i+8]);
+    }
+
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[7],p[0]);
+  draw_line (cr, startx,starty,pw,ph, cx1,cy1,cx2,cy2, p[15],p[8]);
+
+  cairo_set_line_width (cr, 3.0);
+  cairo_stroke_preserve (cr);
+  cairo_set_line_width (cr, 1.0);
+  cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
+  cairo_stroke (cr);
+}