I am trying to implement some support for SVG in my game, actually it will only support rectangles as that's all i need. Anyways, I don't really understand matrices so I'm probably doing something terribly wrong.
Anyways, this is the relevant code:
float x, y, height, width, opacity;
if (rect->QueryFloatAttribute("x", &x) != TIXML_SUCCESS)
return;
if (rect->QueryFloatAttribute("y", &y) != TIXML_SUCCESS)
return;
if (rect->QueryFloatAttribute("width", &width) != TIXML_SUCCESS)
return;
if (rect->QueryFloatAttribute("height", &height) != TIXML_SUCCESS)
return;
if (rect->QueryFloatAttribute("opacity", &opacity) != TIXML_SUCCESS)
opacity = 0.5;
boost::numeric::ublas::vector<float> bottom_left(3);
// Assign x
bottom_left[0] = x;
// Assign y
bottom_left[1] = y;
// Assign z
bottom_left[2] = 0.0;
boost::numeric::ublas::vector<float> bottom_right(3);
bottom_right[0] = x + width;
bottom_right[1] = y;
bottom_right[2] = 0.0;
boost::numeric::ublas::vector<float> top_left(3);
top_left[0] = x;
top_left[1] = y + height;
top_left[2] = 0.0;
boost::numeric::ublas::vector<float> top_right(3);
top_right[0] = x + width;
top_right[1] = y + height;
top_right[2] = 0.0;
// transform may or may not exist
const char * transform = rect->Attribute("transform");
if (transform)
{
using boost::numeric::ublas::column_major;
boost::numeric::ublas::matrix<float> matrix(3, 3);
bool full = boost::spirit::parse(transform,
( // begin grammar
str_p("matrix(") >> real_p[ assign_a( matrix(0, 0) ) ] >> *ch_p(',') >> real_p[ assign_a( matrix(1, 0) ) ] >> *ch_p(',') >> real_p[ assign_a( matrix(0, 1) ) ] >> *ch_p(',') >> real_p[ assign_a( matrix(1, 1) ) ] >> *ch_p(',') >> real_p[ assign_a( matrix(0, 2) ) ] >> *ch_p(',') >> real_p[ assign_a( matrix(1, 2) ) ] >> ch_p(')')
), // end grammar
boost::spirit::space_p).full;
if (!full)
return;
matrix(2, 0) = 0;
matrix(2, 1) = 0;
matrix(2, 2) = 1;
bottom_left = boost::numeric::ublas::prod(matrix, bottom_left);
bottom_right = boost::numeric::ublas::prod(matrix, bottom_right);
top_left = boost::numeric::ublas::prod(matrix, top_left);
top_right = boost::numeric::ublas::prod(matrix, top_right);
/*
bottom_left = boost::numeric::ublas::prod(bottom_left, matrix);
bottom_right = boost::numeric::ublas::prod(bottom_right, matrix);
top_left = boost::numeric::ublas::prod(top_left, matrix);
top_right = boost::numeric::ublas::prod(top_right, matrix);
*/
}
boost::shared_ptr<Rectangle> rectangle(new Rectangle);
rectangle->bottom_left = toVec2(bottom_left);
rectangle->bottom_right = toVec2(bottom_right);
rectangle->top_left = toVec2(top_left);
rectangle->top_right = toVec2(top_right);
rectangles.push_back(rectangle);
I'm using boost::spirit and boost::matrix and boost::vector and TinyXML.
This is how it currently looks in my engine:
And this is how it should look:
Note: Color is not implemented yet.
The relevant svg spec about matrices is here:
http://www.w3.org/TR/SVG11/coords.html#TransformMatrixDefined
The used .svg file is here:
http://rafb.net/p/zMYK1889.html
As you can see the rectangles that doesn't use matrices look correct but those who does looks wrong. (My matrix math is probably wrong)
EDIT: Um, i changed the z coord of the start vectors to 1.0 and it seems to look okay but the .svg is flipped upside down. And clues?
EDIT2: I have the same base .svg orginally exported from Illustrator instead of Inkscape and it still doesn't look correct:
Svg is here:
http://rafb.net/p/MuGjZL59.html
[Edited by - lexs on May 28, 2008 2:59:22 PM]
And this is how it should look:
Note: Color is not implemented yet.
The relevant svg spec about matrices is here: http://www.w3.org/TR/SVG11/coords.html#TransformMatrixDefined
The used .svg file is here: http://rafb.net/p/zMYK1889.html
As you can see the rectangles that doesn't use matrices look correct but those who does looks wrong. (My matrix math is probably wrong)
EDIT: Um, i changed the z coord of the start vectors to 1.0 and it seems to look okay but the .svg is flipped upside down. And clues?
EDIT2: I have the same base .svg orginally exported from Illustrator instead of Inkscape and it still doesn't look correct:
Svg is here: http://rafb.net/p/MuGjZL59.html
[Edited by - lexs on May 28, 2008 2:59:22 PM]
