Added new base class to handle viewBox and preserveAspectRatio.

Updated sp-root, sp-symbol, sp-image, sp-pattern, marker to use new class.
Fixed some viewport issues when % used.

(bzr r13002)

1 files changed, 277 insertions, 0 deletions

diff --git a/src/viewbox.cpp b/src/viewbox.cpp
new file mode 100644
index 000000000..2314cbf6a
--- /dev/null
+++ b/src/viewbox.cpp
@@ -0,0 +1,277 @@
+/*
+ * viewBox helper class, common code used by root, symbol, marker, pattern, image, view
+ *
+ * Authors:
+ *   Lauris Kaplinski <lauris@kaplinski.com> (code extracted from symbol.cpp)
+ *   Tavmjong Bah <tavmjong@free.fr>
+ *
+ * Copyright (C) 2013 Tavmjong Bah, authors
+ *
+ * Released under GNU GPL, read the file 'COPYING' for more information
+ *
+ */
+
+#include <2geom/transforms.h>
+
+#include "viewbox.h"
+#include "attributes.h"
+#include "enums.h"
+#include "sp-item.h"
+
+SPViewBox::SPViewBox() {
+
+  this->viewBox_set  = FALSE;
+
+  this->aspect_set   = FALSE;
+  this->aspect_align = SP_ASPECT_XMID_YMID; // Default per spec;
+  this->aspect_clip  = SP_ASPECT_MEET;
+
+  this->c2p = Geom::identity();
+}
+
+SPViewBox::~SPViewBox() {
+}
+
+void SPViewBox::set_viewBox(const gchar* value) {
+
+  if (value) {
+    double x, y, width, height;
+    char *eptr;
+
+    eptr = (gchar *) value;
+    x = g_ascii_strtod (eptr, &eptr);
+
+    while (*eptr && ((*eptr == ',') || (*eptr == ' '))) {
+      eptr++;
+    }
+
+    y = g_ascii_strtod (eptr, &eptr);
+
+    while (*eptr && ((*eptr == ',') || (*eptr == ' '))) {
+      eptr++;
+    }
+
+    width = g_ascii_strtod (eptr, &eptr);
+
+    while (*eptr && ((*eptr == ',') || (*eptr == ' '))) {
+      eptr++;
+    }
+
+    height = g_ascii_strtod (eptr, &eptr);
+
+    while (*eptr && ((*eptr == ',') || (*eptr == ' '))) {
+      eptr++;
+    }
+
+    if ((width > 0) && (height > 0)) {
+      /* Set viewbox */
+      this->viewBox = Geom::Rect::from_xywh(x, y, width, height);
+      this->viewBox_set = TRUE;
+    } else {
+      this->viewBox_set = FALSE;
+    }
+  } else {
+    this->viewBox_set = FALSE;
+  }
+
+  // The C++ way?
+  // std::string sv( value );
+  // std::replace( sv.begin(), sv.end(), ',', ' ');
+  // std::stringstream ss( sv );
+  // double x, y, width, height;
+  // ss >> x >> y >> width >> height;
+}
+
+void SPViewBox::set_preserveAspectRatio(const gchar* value) {
+
+  /* Do setup before, so we can use break to escape */
+  this->aspect_set = FALSE;
+  this->aspect_align = SP_ASPECT_XMID_YMID; // Default per spec
+  this->aspect_clip = SP_ASPECT_MEET;
+
+  if (value) {
+    int len;
+    gchar c[256];
+    const gchar *p, *e;
+    unsigned int align, clip;
+    p = value;
+
+    while (*p && *p == 32) {
+      p += 1;
+    }
+
+    if (!*p) {
+      return;
+    }
+
+    e = p;
+
+    while (*e && *e != 32) {
+      e += 1;
+    }
+
+    len = e - p;
+
+    if (len > 8) {
+      return;
+    }
+
+    memcpy (c, value, len);
+
+    c[len] = 0;
+
+    /* Now the actual part */
+    if (!strcmp (c, "none")) {
+      align = SP_ASPECT_NONE;
+    } else if (!strcmp (c, "xMinYMin")) {
+      align = SP_ASPECT_XMIN_YMIN;
+    } else if (!strcmp (c, "xMidYMin")) {
+      align = SP_ASPECT_XMID_YMIN;
+    } else if (!strcmp (c, "xMaxYMin")) {
+      align = SP_ASPECT_XMAX_YMIN;
+    } else if (!strcmp (c, "xMinYMid")) {
+      align = SP_ASPECT_XMIN_YMID;
+    } else if (!strcmp (c, "xMidYMid")) {
+      align = SP_ASPECT_XMID_YMID;
+    } else if (!strcmp (c, "xMaxYMid")) {
+      align = SP_ASPECT_XMAX_YMID;
+    } else if (!strcmp (c, "xMinYMax")) {
+      align = SP_ASPECT_XMIN_YMAX;
+    } else if (!strcmp (c, "xMidYMax")) {
+      align = SP_ASPECT_XMID_YMAX;
+    } else if (!strcmp (c, "xMaxYMax")) {
+      align = SP_ASPECT_XMAX_YMAX;
+    } else {
+      return;
+    }
+
+    clip = SP_ASPECT_MEET;
+
+    while (*e && *e == 32) {
+      e += 1;
+    }
+
+    if (*e) {
+      if (!strcmp (e, "meet")) {
+        clip = SP_ASPECT_MEET;
+      } else if (!strcmp (e, "slice")) {
+        clip = SP_ASPECT_SLICE;
+      } else {
+        return;
+      }
+    }
+
+    this->aspect_set = TRUE;
+    this->aspect_align = align;
+    this->aspect_clip = clip;
+  }
+}
+
+// Apply scaling from viewbox
+void SPViewBox::apply_viewbox(const Geom::Rect& in) {
+
+    /* Determine actual viewbox in viewport coordinates */
+    double x = 0.0;
+    double y = 0.0;
+    double width = in.width();
+    double height = in.height();
+    // std::cout << "  width: " << width << " height: " << height << std::endl;
+
+    if (this->aspect_align != SP_ASPECT_NONE) {
+      double scalex, scaley, scale;
+      /* Things are getting interesting */
+      scalex = in.width() / this->viewBox.width();
+      scaley = in.height() / this->viewBox.height();
+      scale = (this->aspect_clip == SP_ASPECT_MEET) ? MIN (scalex, scaley) : MAX (scalex, scaley);
+      width  = this->viewBox.width()  * scale;
+      height = this->viewBox.height() * scale;
+
+      /* Now place viewbox to requested position */
+      switch (this->aspect_align) {
+        case SP_ASPECT_XMIN_YMIN:
+          break;
+        case SP_ASPECT_XMID_YMIN:
+          x = 0.5 * (in.width() - width);
+          break;
+        case SP_ASPECT_XMAX_YMIN:
+          x = 1.0 * (in.width() - width);
+          break;
+        case SP_ASPECT_XMIN_YMID:
+          y = 0.5 * (in.height() - height);
+          break;
+        case SP_ASPECT_XMID_YMID:
+          x = 0.5 * (in.width() - width);
+          y = 0.5 * (in.height() - height);
+          break;
+        case SP_ASPECT_XMAX_YMID:
+          x = 1.0 * (in.width() - width);
+          y = 0.5 * (in.height() - height);
+          break;
+        case SP_ASPECT_XMIN_YMAX:
+          y = 1.0 * (in.height() - height);
+          break;
+        case SP_ASPECT_XMID_YMAX:
+          x = 0.5 * (in.width() - width);
+          y = 1.0 * (in.height() - height);
+          break;
+        case SP_ASPECT_XMAX_YMAX:
+          x = 1.0 * (in.width() - width);
+          y = 1.0 * (in.height() - height);
+          break;
+        default:
+          break;
+      }
+    }
+
+    /* Viewbox transform from scale and position */
+    Geom::Affine q;
+    q[0] = width / this->viewBox.width();
+    q[1] = 0.0;
+    q[2] = 0.0;
+    q[3] = height / this->viewBox.height();
+    q[4] = -this->viewBox.left() * q[0] + x;
+    q[5] = -this->viewBox.top()  * q[3] + y;
+
+    // std::cout << "  q\n" << q << std::endl;
+
+    /* Append viewbox transformation */
+    this->c2p = q * this->c2p;
+}
+
+SPItemCtx SPViewBox::get_rctx(const SPItemCtx* ictx) {
+
+  /* Create copy of item context */
+  SPItemCtx rctx = *ictx;
+
+  /* Calculate child to parent transformation */
+  /* Apply parent translation (set up as viewport) */
+  this->c2p = Geom::Translate(rctx.viewport.min());
+
+  if (this->viewBox_set) {
+    // Adjusts c2p for viewbox
+    apply_viewbox( rctx.viewport );
+  }
+
+  rctx.i2doc = this->c2p * rctx.i2doc;
+
+  /* If viewBox is set initialize child viewport */
+  /* Otherwise it is already correct */
+  if (this->viewBox_set) {
+    rctx.viewport = this->viewBox;
+    rctx.i2vp = Geom::identity();
+  }
+
+  return rctx;
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-basic-offset:2
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=2:tabstop=8:softtabstop=2:fileencoding=utf-8:textwidth=99 :