Improve subpixel rendering time by using a specialized transform - gsl-shell.git - gsl-shell

diff --git a/agg-plot/canvas.h b/agg-plot/canvas.h
index fd618769..3a35a501 100644
--- a/agg-plot/canvas.h
+++ b/agg-plot/canvas.h

@@ -72,6 +72,12 @@ template <class Pixel>

class renderer_subpixel_aa

{

enum { subpixel_scale = 3 };

+

+ struct subpixel_scale_trans

+ {

+ void transform(double* x, double* y) const { *x = subpixel_scale * (*x); }

+ };

+

public:

renderer_subpixel_aa(agg::rendering_buffer& ren_buf, agg::rgba bg_color):

m_pixbuf(ren_buf), m_ren_base(m_pixbuf), m_ren_solid(m_ren_base),

@@ -105,8 +111,8 @@ public:

template <class Rasterizer, class VertexSource>

static void add_path(Rasterizer& ras, VertexSource& vs)

{

- agg::trans_affine_scaling subpixel_mtx(double(subpixel_scale), 1.0);

- agg::conv_transform<VertexSource> scaled_vs(vs, subpixel_mtx);

+ subpixel_scale_trans tr;

+ agg::conv_transform<VertexSource, subpixel_scale_trans> scaled_vs(vs, tr);

ras.add_path(scaled_vs);

}