I'v made a sub for copying a 320x240-16bit buffer to a 640x480-16bit screen. I want to use the 320x240x16 screen mode, but the mode is not supported any all computers, so I need a backup plan
I'v tried to optimize it, but its to slow. Can somebody help me speed it up?
This code is made for the sdl lib, but I havent changed it to work with gfxlib(wich I'm gonna use)
Code:
'buffer and video are Dim'ed as SDL_Surface ptr'rs
sub xCopyBuffer
dim srcOfset as unsigned integer, srcPixel as ushort ptr
dim dstOfset1 as unsigned integer, dstOfset2 as unsigned integer
dim dstPixel as unsigned integer ptr
dim x as integer, y as integer, doublepixel as unsigned integer
srcOfset = 0
dstOfset1 = 0
dstOfset2 = video->pitch
SDL_LockSurface(video)
for y = 0 to 239
for x = 0 to 639 step 2
srcPixel = buffer->pixels + SrcOfset + x
doublepixel = *srcPixel
doublepixel = doublepixel shl 16
doublepixel = doublepixel or *srcPixel
dstPixel = video->pixels + DstOfset1 + (x*2)
*dstPixel = doublepixel
dstPixel = video->pixels + DstOfset2 + (x*2)
*dstPixel = doublepixel
next
srcOfset = srcOfset + buffer->pitch
dstOfset1 = dstOfset1 + (video->pitch*2)
dstOfset2 = dstOfset2 + (video->pitch*2)
next
SDL_UnlockSurface(video)
SDL_Updaterect Video,0,0,0,0
end sub
Search for Rel's scale2x algo he posted a while ago. I think you could also check his website
Thanx, I'll look into it to night
Heh 2min and someone helps out
scale2x is not what Im looking for, I want the blocky scaling not rounding the edges. I want the code to make the 320x240 buffer look the same in a 640x480 mode as it would look in a 320x240 mode, but my algo is to slow..
Rel's demo scaled the bitmap twice, with the "blocky" method and with the "smart method"
Are you reading pixels from the video surface? Try allocating a software surface, because a hardware one will be a magnitude slower, as reading for VRAM is painful slow.
I have ported my xCopyBuffer from sdl to gfxlib, but I have come across a problem. Heres a working example:
Code:
declare sub xCopyBuffer()
TYPE SCREENINFOTYPE
driver_name AS STRING
w AS INTEGER
h AS INTEGER
depth AS INTEGER
pitch AS INTEGER
bpp AS INTEGER
mask_color AS INTEGER
num_pages AS INTEGER
flags AS INTEGER
END TYPE
dim shared buffer(76801) as ushort, info as screeninfotype ptr
buffer(0) = 320 shl 3
buffer(1) = 240
screen 18, 16, 0
info = screeninfo
PRINT STR$(info->w) + "x" + STR$(info->h) + "x" + STR$(info->depth);
PRINT " using " + info->driver_name + " driver"
PRINT "pitch:"; STR$(info->pitch)
do:loop until inkey$ <> ""
for i = 2 to 76801
buffer(i) = rnd*65000
next
'line buffer, (0,0) - (319,239), RGB(255,255,255)
xCopyBuffer
do:loop until inkey$ <> ""
end
sub xCopyBuffer
dim srcOfset as unsigned integer, srcPixel as ushort ptr
dim dstOfset1 as unsigned integer, dstOfset2 as unsigned integer
dim dstPixel as unsigned integer ptr
dim x as integer, y as integer, doublepixel as unsigned integer
srcOfset = 0
dstOfset1 = 0
dstOfset2 = info->pitch
screenlock
for y = 0 to 239
for x = 0 to 639 step 2
srcPixel = varptr(buffer(2)) + SrcOfset + x
doublepixel = *srcPixel
doublepixel = doublepixel shl 16
doublepixel = doublepixel or *srcPixel
dstPixel = screenptr + DstOfset1 + (x*2)
*dstPixel = doublepixel
dstPixel = screenptr + DstOfset2 + (x*2)
*dstPixel = doublepixel
next
srcOfset = srcOfset + 640
dstOfset1 = dstOfset1 + (info->pitch*2)
dstOfset2 = dstOfset2 + (info->pitch*2)
next
screenunlock
end sub
If you try to add the Line command that I have commented out, it crashes.. and I cant understand why. Could someone please help, coz this has troubled me for a couple of days now :barf: