added "scale" affine transformation for graphics pipeline - gsl-shell.git - gsl-shell

diff --git a/agg-plot/agg-parse-trans.cpp b/agg-plot/agg-parse-trans.cpp
index 42f528fa..4547db24 100644
--- a/agg-plot/agg-parse-trans.cpp
+++ b/agg-plot/agg-parse-trans.cpp

@@ -46,6 +46,7 @@ struct property_reg line_join_properties[] = {

const char *agg_spec_error::m_msg[] = {

"invalid specification tag",

"invalid specification table",

+ "missing specification parameter",

"invalid graphical object",

"generic error during graphical operation"

};

@@ -177,6 +178,25 @@ build_translate (lua_State *L, int specindex, typename context::base_type *obj)

}

template <class context> typename context::base_type*

+build_scale (lua_State *L, int specindex, typename context::base_type *obj)

+{

+ typedef typename trans<context>::affine affine_type;

+

+ lua_rawgeti (L, specindex, 2);

+

+ if (! lua_isnumber (L, -1))

+ throw agg_spec_error(agg_spec_error::missing_parameter);

+

+ double s = lua_tonumber (L, -1);

+ lua_pop (L, 1);

+

+ agg::trans_affine mtx(s, 0.0, 0.0, s, 0.0, 0.0);

+ affine_type *t = new affine_type(obj, mtx);

+

+ return (typename context::base_type *) t;

+}

+

+template <class context> typename context::base_type*

build_rotate (lua_State *L, int specindex, typename context::base_type *obj)

{

typedef typename trans<context>::affine affine_type;

@@ -227,6 +247,7 @@ const typename builder<context>::reg builder<context>::builder_table[] = {

{"marker", build_marker <context>},

{"extend", build_extend <context>},

{"translate", build_translate<context>},

+ {"scale", build_scale <context>},

{"rotate", build_rotate <context>},

{NULL, NULL}

};

diff --git a/agg-plot/agg-parse-trans.h b/agg-plot/agg-parse-trans.h
index cd5848f9..66bac15e 100644
--- a/agg-plot/agg-parse-trans.h
+++ b/agg-plot/agg-parse-trans.h

@@ -16,6 +16,7 @@ public:

enum err_e {

invalid_tag = 0,

invalid_spec,

+ missing_parameter,

invalid_object,

generic_error

};

diff --git a/doc/source/graphics.rst b/doc/source/graphics.rst
index 66da1750..f7e539c8 100644
--- a/doc/source/graphics.rst
+++ b/doc/source/graphics.rst

@@ -600,6 +600,11 @@ Here a complete list of all the available transforms:

* **x**, translation along the x axis

* **y**, translation along the y axis

+ **scale**

+ A scaling of the image around the point (0, 0). Only one numeric

+ parameter should be supplied to indicate the scaling factor. For

+ example ``{'scale', 2}`` will scale the image of a factor two.

+

**rotate**

A rotation of a given angle with respect of the origin. This transformation can be used only in the user coordinate system.

diff --git a/examples/fractals.lua b/examples/fractals.lua
index 9f32717f..168ef83e 100644
--- a/examples/fractals.lua
+++ b/examples/fractals.lua

@@ -67,36 +67,16 @@ end

demo2 = function(n) return levyc(n and n or 6) end

-function get_box_gener()

- local pbox = {}

-

- local function get(ll)

- local b = pbox[ll]

- if not b then

- b = rect(0, 0, ll, ll)

- pbox[ll] = b

- end

- return b

- end

-

- local function count()

- local c = 0

- for k, v in pairs(pbox) do c = c+1 end

- return c

- end

- return get, count

-end

-

function demo3()

local rdsd = sqrt(2)/2

+ local ubox = rect(0, 0, 1, 1)

local cf

- local get_box, box_count = get_box_gener()

-

local function pitag_tree(pl, x, y, th, ll, depth)

- local box = get_box(ll)

local col = cf(depth)

- pl:add(box, col, {}, {{'translate', x= x, y= y}, {'rotate', angle= th}})

+ pl:add(ubox, col, {}, {{'translate', x= x, y= y},

+ {'rotate', angle= th},

+ {'scale', ll}})

if depth > 0 then

x, y = x - ll*sin(th), y + ll*cos(th)

pitag_tree(pl, x, y, th + pi/4, ll*rdsd, depth-1)

@@ -113,7 +93,6 @@ function demo3()

pitag_tree(pl, 0, 0, 0, 1, depth)

pl:show()

- print('number of used rectangles:', box_count())

return pl

end

@@ -188,17 +167,16 @@ function demo3ter(n)

end

function demo4(n)

+ local ubox = rect(0, 0, 1, 1)

n = n and n or 10

local col, coln

- local get_box, box_count = get_box_gener()

-

local function pitag_tree(pl, x, y, th, ll, depth)

if depth == 0 then

- local box = get_box(ll)

- local tr = {{'translate', x= x, y= y}, {'rotate', angle= th}}

- pl:add(box, col, {}, tr)

- pl:add(box, coln, {{'stroke', width= 2.5*ll}}, tr)

+ local tr = {{'translate', x= x, y= y}, {'rotate', angle= th},

+ {'scale', ll}}

+ pl:add(ubox, col, {}, tr)

+ pl:add(ubox, coln, {{'stroke', width= 2.5*ll}}, tr)

end

if depth > 0 then

x, y = x - ll*sin(th), y + ll*cos(th)

@@ -212,16 +190,15 @@ function demo4(n)

local cfgen = color_function('darkgreen', 1)

local pl = plot()

- pl.units = false

pl.sync = false

pl:show()

for k=0, n do

col, coln = cfgen(k/n), cfgen((k+1)/n)

pitag_tree(pl, 0, 0, 0, 1, k)

- pl:flush()

+ pl:flush()

end

- print('number of used rectangles:', box_count())

+

return pl

end