Gradient Line

This code has been declared by its author to be Public Domain code.

Gradient Line by DarkEagle

2003

gradient line

Function GradLine(x1,y1,x2,y2,r1,g1,b1,r2,g2,b2)

dx# = x2-x1
dy# = y2-y1

m# = dy/dx

l# = Sqr(dx^2 + dy^2)

rinc# = (r2-r1)/l
ginc# = (g2-g1)/l
binc# = (b2-b1)/l

r# = r1
g# = g1
b# = b1

For x = x1 To x2
	argb = (b Or (g Shl 8) Or (r Shl 16) Or ($ff000000))
	WritePixel x,(m*x)+y1,argb
	r = r + rinc
	g = g + ginc
	b = b + binc
Next

End Function

Comments

Sir Gak

2004

This can be speeded up phenomenally by using Lockbuffer and UnlockBuffer. Using a 1000 reps loop, I measured over 32000 millseconds without LockBuffer. When utilizing LockBuffer, the time drops to about 74 millseconds.

Graphics 800,600
GradLine(100,30,799,530,0,0,0,128,128,255)
MouseWait()
End

Function GradLine(x1,y1,x2,y2,r1,g1,b1,r2,g2,b2)

dx# = x2-x1
dy# = y2-y1

m# = dy/dx

l# = Sqr(dx^2 + dy^2)

rinc# = (r2-r1)/l
ginc# = (g2-g1)/l
binc# = (b2-b1)/l

r# = r1
g# = g1
b# = b1
timer#=MilliSecs()
LockBuffer FrontBuffer()
For loop=1 To 1000
For x = x1 To x2
argb = (b Or (g Shl 8) Or (r Shl 16) Or ($ff000000))
WritePixel x,(m*x)+y1,argb
r = r + rinc
g = g + ginc
b = b + binc
Next
Next
UnlockBuffer FrontBuffer()
Print MilliSecs()-timer
End Function

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