Gardner Lab

Psychology Department

Neurosciences Institute

Stanford University


日本語   

Drawing functions

mglClearScreen

purpose: sets the background color
usage: mglClearScreen(<color>)

argument value
color color to set background to, can be a grayscale value or an [r g b] value

set to the level of gray (0-1)

mglClearScreen(gray)

set to the given [r g b]

mglClearScreen([r g b])

full example

mglOpen;
mglClearScreen([0.7 0.2 0.5]);
mglFlush();

mglPoints2: 2D points

purpose: plot 2D points on an OpenGL screen opened with mglOpen. For round dots, use mglGluDisk.
usage: mglPoints2(x,y,size,color)

argument value
x,y position of dots on screen
size size of dots (height of square in pixels)
color color of dots
mglOpen;
mglVisualAngleCoordinates(57,[16 12]);
mglPoints2(16*rand(500,1)-8,12*rand(500,1)-6,2,1);
mglFlush

mglPoints3: 3D points

purpose: plot 3D points on an OpenGL screen opened with mglOpen
usage: mglPoints2(x,y,z,size,color)

argument value
x,y,z position of dots on screen
size size of dots (in pixels)
color color of dots
mglOpen;
mglVisualAngleCoordinates(57,[16 12]);
mglPoints3(16*rand(500,1)-8,12*rand(500,1)-6,zeros(500,1),2,1);
mglFlush


mglLines2: 2D lines

purpose: mex function to plot lines on an OpenGL screen opened with glopen
usage: mglLines(x0, y0, x1, y1,size,color)

argument value
x0,y0 initial position of line
x1,y1 end position of line
size size of line (in pixels)
color color of line
mglOpen
mglVisualAngleCoordinates(57,[16 12]);
mglLines2(-4, -4, 4, 4, 2, [1 0.6 1]);
mglFlush

mglFillOval: Ovals

purpose: draw filled oval(s) centered at x,y with size [xsize ysize] and color [rgb]. the function is vectorized, so if you provide many x/y coordinates (identical) ovals will be plotted at all those locations.
usage: mglFillOval(x,y, size, color)

argument value
x,y center position of oval
size [width height] of oval
color color of oval
mglOpen;
mglVisualAngleCoordinates(57,[16 12]);
x = [-1 -4 -3 0 3 4 1];
y = [-1 -4 -3 0 3 4 1];
sz = [1 1];
mglFillOval(x, y, sz,  [1 0 0]);
mglFlush();

mglFillRect: Rectangles

purpose: draw filled rectangles(s) centered at x,y with size [xsize ysize] and color [rgb]. the function is vectorized, so if you provide many x/y coordinates (identical) ovals will be plotted at all those locations.
usage: [ ] = mglFillRect(x,y, size, color)

argument value
x,y center position of rectangle
size [width height] of rectangle
color color of rectangle
mglOpen;
mglVisualAngleCoordinates(57,[16 12]);
x = [-1 -4 -3 0 3 4 1];
y = [-1 -4 -3 0 3 4 1];
sz = [1 1];
mglFillRect(x, y, sz,  [1 1 0]);
mglFlush();


mglFixationCross: Cross

purpose: draws a fixation cross. With no arguments, draws a fixation cross at origin (default width 0.2 with linewidth 1 in white at [0,0])
usage: mglFixationCross([width], [linewidth], [color], [origin]);
alternate usage: mglFixationCross( params )

argument value
params [width linewidth r g b x y]
width width in degrees of fixation cross
linewidth width in pixels on line
color color of fixation cross
origin center position of fixation (defaults to [0 0])
mglOpen;
mglVisualAngleCoordinates(57,[16 12]);
mglFixationCross;
mglFlush;

mglGluAnnulus: Annuli, rings

purpose: for annuli and rings, e.g. for retinotopic stimuli. The function is vectorized, such that multiple annuli can be rendered in one call. In this case, x,y, isize, and osize need to have the same number of elements. Color is also vectorized.
usage: [ ] = mglGluAnnulus( x, y, isize, osize, color, [nslices], [nloops] )

argument value
x,y position of circle from which annulus/annuli is/are derived
isize inner radius/radii
osize outer radius/radii
color color of annuli, either [], 3-vector, or 3-row by n-column matrix
nslices number of wedges used in polygon→circle approximation [default 8]
nloops number of annuli used in polygon→circle approximation [default 1]
 mglOpen(0);
 mglVisualAngleCoordinates(57,[16 12]);
 x = zeros(4, 1);
 y = zeros(4, 1);
 isize = linspace(1, 8, 4);
 osize = isize+linspace(0.1, 2, 4);
 colors = jet(4)';
 mglGluAnnulus(x, y, isize, osize,colors , 60, 2);
 mglFlush();


mglGluDisk: Circular dots

purpose: for plotting circular (rather than square dots), use this function. on slower machines, large number of dots may lead to dropped frames. there may be a way to speed this up a bit in future.
usage: [ ] = mglGluDisk( x, y, size, color, [nslices], [nloops] )

argument value
x,y position of dots
size size of dots (radius)
color color of dots
nslices number of wedges used in polygon→circle approximation [default 8]
nloops number of annuli used in polygon→circle approximation [default 1]
mglOpen;
mglVisualAngleCoordinates(57,[16 12]);
x = 16*rand(100,1)-8;
y = 12*rand(100,1)-6;
mglGluDisk(x, y, 0.1,  [0.1 0.6 1], 24, 2);
mglFlush();


mglGluPartialDisk: Segments, wedges

purpose: for segments and wedges, e.g. for retinotopic stimuli. The function is vectorized, such that multiple segments can be rendered in one call. In this case, x,y, isize, osize, startAngles, and sweepAngles need to have the same number of elements. Color is also vectorized (see mglGluAnnulus and the example below).
usage: [ ] = mglGluPartialDisk( x, y, isize, osize, startAngles, sweepAngles, color, [nslices], [nloops] )

argument value
x,y center position of circle from which segment is derived
isize innter radius of segment
osize outer radius of segment
startAngles angle at which segment(s) start
sweepAngles angle each segment(s) sweep(s) out
color color of segment
nslices number of wedges used in polygon→circle approximation [default 8]
nloops number of annuli used in polygon→circle approximation [default 2]
mglOpen(0);
mglVisualAngleCoordinates(57,[16 12]);
x = zeros(10, 1);
y = zeros(10, 1);
isize = linspace(1, 5, 10);
osize = 3+isize;
startAngles = linspace(0,180, 10)
sweepAngles = ones(1,10).*10;
colors = jet(10)';
mglGluPartialDisk(x, y, isize, osize, startAngles, sweepAngles, colors, 60, 2);
mglFlush();

mglPolygon: Polygons

purpose: mex function to draw a polygon in an OpenGL screen opened with mglOpen. x and y can be vectors (the polygon will be closed)
usage: mglPolygon(x, y, [color])

argument value
x,y position of vertices
color color of polygon
mglOpen;
mglVisualAngleCoordinates(57,[16 12]);
x = [-5 -6 -3  4 5];
y = [ 5  1 -4 -2 3];
mglPolygon(x, y, [1 0 0]);
mglFlush();

mglQuads: Quads

usage: mglQuad( vX, vY, rgbColor, [antiAliasFlag] );
purpose: mex function to draw a quad in an OpenGL screen opened with mglOpen

argument value
vX 4 row by N column matrix of 'X' coordinates
vY 4 row by N column matrix of 'Y' coordinates
rgbColors 3 row by N column of r-g-b specifing the color of each quad
antiAliasFlag turns on antialiasing to smooth the edges


mglOpen;
mglScreenCoordinates
mglQuad([100; 600; 600; 100], [100; 200; 600; 100], [1; 1; 1], 1);
mglFlush();