A reserved word in surf's language is either a command or a global variable. A command is invoked mostly without parameters. Global variables are either constant or may be altered. The commands correspond to pushbuttons of surf's GUI, global variables correspond to other panel items.
res. word | type | description
--------------------------------------------------------------------------
clear_screen | command | erase the image
clear_pixmap | command | erase the image in memory (useful for
| | real-time-animations of algebraic curves)
draw_curve | command | draw the curve defined by the global
| | polynomial curve
draw_surface | command | draw the surfaces defined by the global
| | polynomials surface, surface2, ...
cut_with_plane | command | draw the hyperplane section defined
| | defined by the linear polynomial plane
dither_surface | command | convert color image to a dithered
| | black and white image
dither_curve | command | convert color image to a dithered
| | black and white image (for curves only)
save_color_image | command | save color image in file defined by the
| | global string filename
save_dithered_image | command | save dithered black and white image in
| | file defined by the global string filename
set_size | command | not needed any more (still there for
| | compatibility issues)
res. word | type | range | default | description
-------------------------------------------------------------------------
curve | poly | any | 0 | polynomial of curve
surface | poly | any | 0 | polynomial of surface
surface2 | poly | any | 0 | polynomial of surface2
... | ... | ... | ... | ...
surface9 | poly | any | 0 | polynomial of surface9
plane | poly | linear | 0 | equation of hyperplane
width | int | {64,...,3000} | 200 | width of surface image
height | int | {64,...,3000} | 200 | height of surface image
filename | string | any | "" | filename used in
| | | | save_color_image,
| | | | save_dithered_image
surf_nr | int | {1,...,9} | 1 | surface which is used
| | | | for cut_with_plane
width=400; // Set image width
height=300; // and height
surface=x^2+y^2+z^2-81; // Set global variable surface to a sphere
draw_surface; // Draw the sphere onto the screen
plane=x+y+z; // Choose a hyperplane
cut_with_plane; // Draw the hyperplane section
filename="sphere.ras";
save_color_image; // Save the color image in file sphere.xwd
dither_surface; // Perform dithering on the color image
filename="sphere.ps";
save_dithered_image; // Save the dithered image in sphere.ps
res. word | type | range | def. | description
-------------------------------------------------------------------------
origin_x | double | ]-9999,9999[ | 0 | \
origin_y | double | ]-9999,9999[ | 0 | > position of origin
origin_z | double | ]-9999,9999[ | 0 | /
spec_z | double | ]0,9999[ | 100 | spectator dist. from origin
rot_x | double | ]-9999,9999[ | 0 | rotation angle of surface
| | | | about the x-axis
rot_y | double | ]-9999,9999[ | 0 | rotation of surface
| | | | about the y-axis
rot_z | double | ]-9999,9999[ | 0 | rotation of surface
| | | | about the z-axis
scale_x | double | ]-9999,9999[ | 1 | ratio surface is scaled in
| | | | direction of the x-axis
scale_y | double | ]-9999,9999[ | 1 | ratio surface is scaled in
| | | | direction of the y-axis
scale_z | double | ]-9999,9999[ | 1 | ratio surface is scaled in
| | | | direction of the z-axis
perspective | int | {0,1} | 0 | perspective to use
parallel | int | 0 | 0 | constant
central | int | 1 | 1 | constant
first | int | {0,1,2} | 0 | first performed \
second | int | {0,1,2} | 1 | second performed > action
third | int | {0,1,2} | 2 | third performed /
translate | int | 0 | 0 | constant
rotate | int | 1 | 1 | constant
scale | int | 2 | 2 | constant
double Pi=2*arccos(0);
origin_x = -3;
origin_y = -4; // Set origin to point (-3,-4,2)
origin_z = 2;
spec_z = 25; // Spectator is now at (-3,-4,27)
rot_x = Pi/2; // Rotate 90 degrees about x-axis
rot_y = Pi/4; // Rotate 45 degrees about y-axis
rot_z = Pi; // Rotate 180 degrees about z-axis
scale_x = 1.0; // Don't scale in x-direction
scale_y = 1.5; // Shrink surface in y-direction
scale_z = 1/2; // Oversize surface in z-direction
first = rotate; // rotate first
second = scale; // then scale
third = translate; // then translate
res. word | type | range | def. | description
-------------------------------------------------------------------------
dither_colors | int | {yes,no} | yes | color dithering
dither_steps | double | [5,...,255] | 20.0 | steps of dithering
normalize | int | {yes,no} | no | normalize image
normalize_factor | double | ]0,...,5] | 1.0 | multiply with
antialiasing | int | {1,..,8} | 1 | level of
| | | | antialiasing
antialiasing_threshold | double | ]0,1[ | 0.1 | threshold
antialiasing_radius | double | [0.5,...,2] | 2.0 | radius
depth_cueing | int | {yes,no} | no | use depth cueing
depth_value | double | [-1000,10[ | -14.0 | depth of mist
stereo_eye | double | [-100,100] | 0.0 | eye distance
stereo_z | double | [-30,30] | 5.0 | dist. from screen
stereo_red | double | [0,1] | 1.0 | left eye red
stereo_green | double | [0,1] | 0.7 | right eye green
stereo_blue | double | [0,1] | 0.0 | right eye blue
dither_colors = yes; // perform color dithering
dither_steps = 60.0; // use soft dithering
normalize = yes;
normalize_factor = 1.5; // light up image
antialiasing = 4; // do 4 fold antialiasing
antialiasing_threshold = 0.05; // with a low threshold
antialiasing_radius = 1.5; // and a small radius
depth_cueing = yes; // perform depth cueing
depth_value = -11.0;// from -11 on everythin is dark
stereo_eye = 5.0; // make a red-blue image
stereo_z = 2.0; // object 2 units before screen
stereo_red = 1.0;
stereo_green = 0.0;
stereo_blue = 1.0;
res. word | cat. | range | def. | description
-------------------------------------------------------------------------
illumination | int | {0,..15} | 7 | illumination model
ambient_light | int | 1 | 1 | constant
diffuse_light | int | 2 | 2 | constant
reflected_light | int | 4 | 4 | constant
transmitted_light | int | 8 | 8 | constant
surface_red | int | {0,...,255} | 123 | \ outside
surface_green | int | {0,...,255} | 104 | > color of surface
surface_blue | int | {0,...,255} | 238 | / (medium slate blue)
inside_red | int | {0,...,255} | 230 | \ inside
inside_green | int | {0,...,255} | 180 | > color of surface
inside_blue | int | {0,...,255} | 30 | / (golden)
surface2_red | int | {0,...,255} | 123 | \ outside
surface2_green | int | {0,...,255} | 104 | > color of surface2
surface2_blue | int | {0,...,255} | 238 | / (medium slate blue)
inside2_red | int | {0,...,255} | 230 | \ inside
inside2_green | int | {0,...,255} | 180 | > color of surface2
inside2_blue | int | {0,...,255} | 30 | / (golden)
... | ... | ... | ... | ...
... | ... | ... | ... | ...
... | ... | ... | ... | ...
surface9_red | int | {0,...,255} | 123 | \ outside
surface9_green | int | {0,...,255} | 104 | > color of surface9
surface9_blue | int | {0,...,255} | 238 | / (medium slate blue)
inside9_red | int | {0,...,255} | 230 | \ inside
inside9_green | int | {0,...,255} | 180 | > color of surface9
inside9_blue | int | {0,...,255} | 30 | / (golden)
ambient | int | {0,...,100} | 35 | amount of ambient light
diffuse | int | {0,...,100} | 60 | diffuse reflected light
reflected | int | {0,...,100} | 60 | specular reflected light
transmitted | int | {0,...,100} | 60 | spec. transmitted light
smoothness | int | {0,...,100} | 13 | roughness of surface
transparency | int | {0,...,100} | 80 | transparency of surface
ambient2 | int | {0,...,100} | 35 | amount of ambient light
diffuse2 | int | {0,...,100} | 60 | diffuse reflected light
reflected2 | int | {0,...,100} | 60 | specular reflected light
transmitted2 | int | {0,...,100} | 60 | spec. transmitted light
smoothness2 | int | {0,...,100} | 13 | roughness of surface2
transparency2 | int | {0,...,100} | 80 | transparency of surface2
... | ... | ... | ... | ...
... | ... | ... | ... | ...
... | ... | ... | ... | ...
ambient9 | int | {0,...,100} | 35 | amount of ambient light
diffuse9 | int | {0,...,100} | 60 | diffuse reflected light
reflected9 | int | {0,...,100} | 60 | specular reflected light
transmitted9 | int | {0,...,100} | 60 | spec. transmitted light
smoothness9 | int | {0,...,100} | 13 | roughness of surface9
transparency9 | int | {0,...,100} | 80 | transparency of surface9
light1_x | double | [-9999,9999] | -100 | \
light1_y | double | [-9999,9999] | 100 | \ position and volume
light1_z | double | [-9999,9999] | 100 | / of the first light
light1_vol | int | {0,...,100} | 50 | / source
light1_red | int | {0,..,255} | 255 | \
light1_green | int | {0,..,255} | 255 | > color of first
light1_blue | int | {0,..,255} | 255 | / light source
light2_x | double | [-9999,9999] | 0 | \
light2_y | double | [-9999,9999] | 100 | \ position and volume
light2_z | double | [-9999,9999] | 100 | / of the second light
light2_vol | int | {0,...,100} | 0 | / source
light2_red | int | {0,..,255} | 255 | \
light2_green | int | {0,..,255} | 255 | > color of second
light2_blue | int | {0,..,255} | 255 | / light source
... | ... | ... | ... | ...
... | ... | ... | ... | ...
... | ... | ... | ... | ...
light9_x | double | [-9999,9999] | 100 | \
light9_y | double | [-9999,9999] | -100 | \ position and volume
light9_z | double | [-9999,9999] | 100 | / of the ninteh light
light9_vol | int | {0,...,100} | 0 | / source
light9_red | int | {0,..,255} | 255 | \
light9_green | int | {0,..,255} | 255 | > color of nineth
light9_blue | int | {0,..,255} | 255 | / light source
illumination = ambient_light
+ diffuse_light
+ reflected_light
+ transmitted_light; // Select illumination
surface_red = 205;
surface_green = 92;
surface_blue = 92; // Select indian red for surface outside
inside_red = surface_red;
inside_green = surface_green;
inside_blue = surface_blue; // Select indian red for surface inside
ambient = 10; // 40% ambient light
diffuse = 60; // 60% diffuse light
reflected = 60; // 60% reflected light
transmitted = 70; // 60% reflected light
smoothness = 50; // make surface shiny
transparence = 90; // very transparent
thickness = 20; // but also very thick
light2_x = 100;
light2_y = 0;
light2_z = 200;
light2_volume = 100; // turn on light no. 2 red at (100,0,200)
light2_red = 255;
light2_green = 0;
light2_blue = 0;
reserved word | cat. | range | def. | description
-------------------------------------------------------------------------
clip | int | {0,...,5} | 0 | clipping area
ball | int | 0 | 0 | constant
cylinder_xaxis | int | 1 | 1 | constant
cylinder_yaxis | int | 2 | 2 | constant
cylinder_zaxis | int | 3 | 3 | constant
cube | int | 4 | 4 | constant
none | int | 5 | 5 | constant
clip_front | double | [-9999,9999] | 10 | \ additional clip region
clip_back | double | [-9999,9999] | -10 | /
radius | double | ]0,9999] | 10 | radius of clip region
center_x | double | [-9999,9999] | 0 | \
center_y | double | [-9999,9999] | 0 | > center of clip region
center_z | double | [-9999,9999] | 0 | /
clip = cube;
radius = 7;
center_x = -3; // Set clipping area to cube with center at
center_y = 2; // (-3,2,1) and edge length 14
center_z = 1;
clip_front = 4; // Clip off points with z > 4
clip_back = -10; // Clip off points with z > -10
reserved word | cat. | range | def. | description
-------------------------------------------------------------------------
dithering_method | int | {0,...,6} | 1 | dithering method
floyd_steinberg_filter | int | 0 | 0 | constant
jarvis_judis_ninke_filter | int | 1 | 1 | constant
stucki_filter | int | 2 | 2 | constant
clustered_dot_ordered_dither | int | 3 | 3 | constant
dispersed_dot_ordered_dither | int | 4 | 4 | constant
dot_diffusion | int | 5 | 5 | constant
smooth_dot_diffusion | int | 6 | 6 | constant
reserved word | cat. | range | def. | description
-------------------------------------------------------------------------
serpentine_raster | int | {yes,no} | yes | use of serpentine raster
random_weights | int | {yes,no} | yes | use of random weights
weight | double | [0,1] | 0.5 | amount of random weights
barons | int | {0,1} | 1 | number of barons
one_baron | int | 0 | 0 | constant
two_baron | int | 1 | 1 | constant
pattern_size | int | {0,1,2} | 1 | size of dithering tile
pattern_4x4 | int | 0 | 0 | constant
pattern_8x8 | int | 1 | 1 | constant
pattern_16x16 | int | 2 | 2 | constant
enhance_edges | int | {yes,no} | yes | enhance edges of b w image
alpha | double | [0,1] | 0.9 | filter coefficient used in
| | | | for enhancing the edges
background | double | [0,1] | 1.0 | background intensity of
| | | | b w image
tone_scale_adjustment | int | {yes,no} | yes | perform tone scale adjust.
gamma | double | ]0,oo[ | 1.3 | gamma-correction
pixel_size | int | ]50,100] | 73 | correction for printers
| | | | that produce too fat pixels
dithering_method = stucki_filter; // select stucki filter
serpentine_raster = yes; // turn on serpentine raster
random_weights = yes; // turn on random weights
weight = 0.5; // select 50% weights
enhance_edges = yes; // turn on enhancing edges
alpha = 0.8; // edges less visible than default
background = 0.5; // gray background for b w image
tone_scale_adjustment = yes; // perform tone scale adjustment
gamma = 1.5; // more gamma-correction than default
dithering_method = dispersed_dot; // select dispersed dot ordered dither
pattern_size = pattern_16x16; // select a 16x16-tile
dithering_method = dot_diffusion; // select dot-diffusion
barons = two_barons; // select a 2-barons tile
reserved word | type | range | def. | description
-------------------------------------------------------------------------
color_file_format | int | {0,1} | 1 | file format
xwd | int | 0 | 0 | constant
sun | int | 1 | 1 | constant
color_file_colormap | int | {0,1,2} | 0 | colormap type
netscape | int | 0 | 0 | constant
optimized | int | 1 | 1 | constant
truecolor | int | 2 | 2 | constant
color_file_format = xwd;
color_file_colormap = truecolor; // format is 24 bit XWD
reserved word | type | range | def. | description
-------------------------------------------------------------------------
resolution | int | {0,...,5} | 3 | (printer) resolution
res_75dpi | int | 0 | 0 | constant
res_100dpi | int | 1 | 1 | constant
res_150dpi | int | 2 | 2 | constant
res_300dpi | int | 3 | 3 | constant
res_600dpi | int | 4 | 4 | constant
res_1200dpi | int | 5 | 5 | constant
dithered_file_format | int | {0,...,4} | 2 | file format
postscript | int | 0 | 0 | constant
encapsulated | int | 1 | 1 | constant
xbm | int | 2 | 2 | constant
tiff | int | 3 | 3 | constant
bm2font | int | 4 | 4 | constant
resolution = res_300dpi; // select 300 dpi
dithered_file_format = bm2font; // TeX pk
reserved word | cat. | range | def. | description
---------------------------------------------------------------------------
root_finder | int | {0,...,6} | 6 | used root finder
d_chain_bisection | int | 0 | 0 | constant
d_chain_regula_falsi | int | 1 | 1 | constant
d_chain_pegasus | int | 2 | 2 | constant
d_chain_illinois | int | 3 | 3 | constant
d_chain_anderson_bjoerck | int | 4 | 4 | constant
d_chain_newton | int | 5 | 5 | constant
bezier_all_roots | int | 6 | 6 | constant
epsilon | double | ]0,1[ | 1e-4 | precision of
| | | | root finder
iterations | int | [1,2000] | 200 | max. number of
| | | | iterations
root_finder = d_chain_bisection; // Slow, but safe
epsilon = 1.0e-7; // Work very precise
iterations = 80; // max. 80 iterations on each root
reserved word | type | range | def. | description
---------------------------------------------------------------------------
curve_red | int | {0,...,255} | 255 | \
curve_green | int | {0,...,255} | 255 | > curve color
curve_blue | int | {0,...,255} | 255 | /
curve_width | double | {1,2,...} | 1 | width of curve
curve_gamma | double | ]0,oo[ | 4.0 |
curve_red =0;
curve_green=255;
curve_blue =0; // make the curve look green
curve_width=6.0; // thick curve
curve_gamma=2.0; // intensity increases slower