Draw the South Korean flag
Python + Pycairo, 371 370 366 bytes
from cairo import*
p=3.141593
c=Context(SVGSurface("F",12,8))
C=c.set_source_rgb;R=c.rectangle;T=c.rotate;F=c.fill
C(1,1,1);R(0,0,12,8);F()
c.translate(6,4);T(.588);b=3188
for o in[(0,.2,.47),(.77,.05,.19)]*2:C(*o);i=b/2%2;b+=1;c.arc(i,0,2-i,0,p+i*p);F();T(p)
C(0,0,0)
for x in(p,1.966)*2:
for y in.5,0,1:
for z in-1,1:R(3+y,-z,1./3,z*(2.75+b%2)/3);F()
b/=2
T(x)
Outputs a tiny SVG file named F.
HTML + CSS, 966 906 843 792 762 bytes
Not a winner anytime, but lots of fun drawing in CSS. This can be golfed a lot though.
CSS, HTML:
*{position:fixed}a{background:linear-gradient(0deg,#003478 50%,#C60C30 50%);width:2in;height:2in;transform:rotate(.6rad);top:1in;left:2in}d,e{width:50%;height:50%;background:#C60C30;left:0;top:25%}a,d,e{border-radius:50%}d{background:#003478;left:50%}b,i{width:1in;height:26em;top:-1em;left:15em;transform:rotate(.98rad)}g,f,k,j{width:1in;height:17%;background:repeating-linear-gradient(0deg,#000,#000 1em,#fff 1em,#fff 1.5em);bottom:0;left:0}g,j,p{top:-.5em}b{transform:rotate(-.98rad)}c,p,v,x{height:2em;width:.5em;background:#fff;transform:rotate(.98rad)}p{top:2.8in;left:28em;transform:rotate(-.98rad) scale(1,4)}x{top:3.9em;left:28.4em}c,v{top:23.8em;transform:none}c{top:3.5em}body{height:4in;width:6in;border:1px solid<a><d><e></a><b><f><g></b><i><j><k></i><p></p><x><v><c;border:1px solid is just for show as the <body> tag has clear boundaries which can be observed by Inspector or similar tools, as stated by the OP
NOTE Works only in Firefox (or Chrome canary/dev) due to usage non vendor specific transforms and gradients.
See it in action
BBC Basic, 349 343 ASCII characters, tokenised file size 330
Download emulator at http://www.bbcbasic.co.uk/bbcwin/bbcwin.html
p=1049q=25r=100VDU4118;275;-1,49,3076;19,7,-1;-1;531;255;7693;q;40;0;q,97,1200;800;29,640;400;
FORa=38TO56STEP0.01x=r*COS(a)y=r*SIN(a)b=a*7DIV44/2IFb=3.5z=y<0ELSEz=x>0
VDU18;1,p;-x;-y;q,153,r;0;18;2,p;x;y;q,153,r;0;18;0
IFABS(y)DIV1=56VDUp;x*b+y;y*b-x;q;x/3;y/3;q,113,-2*y;2*x;18;7:b-=0.1VDUp;x*b+y/12;y*b-x/12;q;x/2;y/2;q,112-z,-y/6;x/6;
NEXT
Using the correct colours added a lot, but golfing all the graphics commands down to raw VDU codes gives a saving of 6 characters overall compared with my original post. All graphics on the BBC micro is done via machine-specific ASCII control codes, so instead of using high-level graphics commands you can feed bytes direct to the VDU controller (generally shorter but at great expense to readability). A value ending in semicolon instead of comma is a 16-bit little-endian representation of 2 bytes.
Ungolfed version
MODE16
VDU19,1,-1,49,4,12 :REM adjust shade of red
VDU19,7,-1,-1,-1,-1 :REM adjust shade of white to full brightness (63 is 2's complement representation of -1
VDU19,4,-1,0,13,30 :REM adjust shade of blue
RECTANGLEFILL40,0,1200,800 :REM plot background rectangle
ORIGIN640,400
FORa=38TO56STEP0.01
x=COS(a)*100
y=SIN(a)*100
GCOL1:CIRCLEFILL-x,-y,100 :REM red
GCOL4:CIRCLEFILLx,y,100 :REM blue
GCOL0 :REM black
b=a*7DIV44/2 :REM divide a by 2*(22/7) to get integer representation, then divide by 2 again.
IFb=3.5THENz=y<0ELSEz=x>0 :REM decide whether to cut bar
REM If the angle is correct (100*sin(a) = 56) draw bar. If required, cut out the middle of the bar.
IFABS(INT(y))=56 MOVEx*b+y,y*b-x:MOVEBY x/3,y/3:PLOT113,-2*y,2*x:GCOL7:b-=0.1:MOVEx*b+y/12,y*b-x/12:MOVEBY x/2,y/2:IFz PLOT113,-y/6,x/6
NEXT
At the beginning of the program I move the origin to the centre of the screen.
I don't draw any large coloured half circles. Instead I run a loop that draws small red and blue circles, spinning in an anticlockwise direction. I do nearly 3 complete revolutions (starting with blue at the right) which is obviously more than enough to fill in the disc. I stop on the 3rd revolution, just when the blue at lower right is in the correct position to line up with the bars (which have to be plotted.)
When the angle is right, I draw one of the bars. the vector x,y for drawing the current small blue circle serves to tell in which direction the bar should be. For each of the 3 revolutions, a different value of the integer a*7DIV44 is calculated, which tells whether the first, second or third bar should be drawn, with its inner edge 6/8,7/8 or 8/8 units from the centre (according to the units used in the question spec.) Because the program units are 1/4 of those in the spec, this is still a half-unit, so we divide by 2 again before saving to variable ´b´ to avoid repeated halving later.
The bars are drawn solid, then the middle is deleted if necessary. This prevents kinks from joining half-bars. The variable z indicates if a bar should be cut. That is, when y is negative for the middle bars and when x is positive for the other bars.
MOVE is an absolute move. MOVEBY is a relative move. PLOT133 considers the last two graphics cursor positions, plus the new one specified (in relative coordinates) as three corners of a parallelogram, and plots that parallelogram.
Output (& discussion of language limitations)
I selected a screen mode of 1280x800 logical pixels = 640x400 physical pixels, which by default has a black background. Onto this I draw a white rectangle from -600,-400 to 600,400 to act as my "canvas."
BBC Basic can handle 16 colours at once, from a reprogrammable pallete. But it only supports 18-bit colour, whereas the question specifies the colours as 24-bit. The colours as close as possible.
