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Problem Setting Up Backgrounds and VRAM
Posted: Wed Feb 20, 2013 5:01 pm
by TiagoGomes
I've been working on a project for nds lately and got stuck on a problem while trying to setup backgrounds.
As a starting point I tried the following setup:
> Mainscreen: Text and BMP Framebuffer
> Subscreen: BMP Framebuffer
Here is the code:
Code: Select all
System::System( void )
{
videoSetMode ( MODE_5_2D );
videoSetModeSub( MODE_5_2D );
vramSetBankA( VRAM_A_MAIN_BG );
vramSetBankB( VRAM_B_MAIN_BG );
vramSetBankC( VRAM_C_SUB_BG );
consoleInit( NULL, 0, BgType_Text4bpp, BgSize_T_256x256, 4, 0, true, true );
bgIndex = bgInit( 2, BgType_Bmp16, BgSize_B16_256x256, 5, 0 );
this->mainScreen.setFrameBuffer( ( u16 * ) bgGetGfxPtr( bgIndex ) );
bgIndex = bgInitSub( 3, BgType_Bmp16, BgSize_B16_256x256, 0, 0 );
this->subScreen.setFrameBuffer( ( u16 * ) bgGetGfxPtr( bgIndex ) );
}
The problem is whenever I try to draw on the buffers and print text I get graphic artifacts, which from what I read is probably being caused by backgrounds sharing the same piece of VRAM memory, but I can't figure out how to properly setup my backgrounds.
I'd really appreciate if anyone could help me with this problem and maybe give some insight on how to setup Backgrounds and VRAM Banks.
Thanks in advance.
Re: Problem Setting Up Backgrounds and VRAM
Posted: Mon Feb 25, 2013 4:23 pm
by mtheall
This is sort of a duplicate of
this post, but with
these settings, but in this example VRAM_B is correctly mapped to account for going over the 128KB boundary. This setup should not be experiencing artifacts, so we may need more info about what you're doing (maybe paste the code where you're drawing).
Re: Problem Setting Up Backgrounds and VRAM
Posted: Mon Feb 25, 2013 10:50 pm
by elhobbs
you may want to take a look at this in an emulator like desmume. It may be something as simple as layer 1 being active/visible and showing garbage. with an emulator you can look at each layer individually.
Re: Problem Setting Up Backgrounds and VRAM
Posted: Tue Feb 26, 2013 9:26 pm
by TiagoGomes
Yes mtheall, this was a duplication of
this post and that's my bad. As a first time poster I didn't notice posts had to be accepted by administrator and I thought it was some sort of error my post the fact that my post did not appear, so I posted again.
Regarding the problem, here is a screenshot of my result with the following code.
Code used for initialization:
Code: Select all
System::System( void )
{
videoSetMode ( MODE_5_2D );
videoSetModeSub( MODE_5_2D );
vramSetBankA( VRAM_A_MAIN_BG );
vramSetBankB( VRAM_B_MAIN_BG );
vramSetBankC( VRAM_C_SUB_BG );
consoleInit( NULL, 0, BgType_Text4bpp, BgSize_T_256x256, 4, 0, true, true );
bgIndex = bgInit( 2, BgType_Bmp16, BgSize_B16_256x256,5, 0 );
this->mainScreen.setFrameBuffer( ( u16 * ) bgGetGfxPtr( bgIndex ) );
bgIndex = bgInitSub( 3, BgType_Bmp16, BgSize_B16_256x256, 0, 0 );
this->subScreen.setFrameBuffer( ( u16 * ) bgGetGfxPtr( bgIndex ) );
}
Redraw function:
Code: Select all
static Framework::Geometry::Rectangle area( 0, 0, 100, 100 );
void drawScreens( void )
{
if ( !contains )
{
systemHandler->subScreen.drawRectangle ( area, Framework::Util::Color::CYAN );
systemHandler->mainScreen.drawRectangle( area, Framework::Util::Color::CYAN );
} else
{
systemHandler->subScreen.drawRectangle ( area, Framework::Util::Color::BLACK );
systemHandler->mainScreen.drawRectangle( area, Framework::Util::Color::BLACK );
}
consoleClear( );
printf( "Player 1 life points: %d\n", player1.lifePoints );
printf( "Player 2 life points: %d\n", player2.lifePoints );
}
drawRectangle method:
Code: Select all
void Screen::drawRectangle( const Geometry::Rectangle & rec ,
u16 color,
uint8 layer )
{
for ( auto column = rec.bottomLeft.x; column < rec.topRight.x; ++column )
{
for ( auto line = rec.bottomLeft.y; line < rec.topRight.y; ++line )
{
this->frameBuffer[ line * 256 + column ] = color;
}
}
}
As you can see, a blue and a noisy line appear.
Thanks for your time.
Re: Problem Setting Up Backgrounds and VRAM
Posted: Sat Mar 16, 2013 5:01 pm
by TiagoGomes
Sorry for not replaying in a while, I was busy with my university.
Anyway, I actually found out what the problem was, it was caused by a call to "consoleDemoInit()", which I forgot to take out and was setting VRAM_C for text, prior to the code snippet I showed. After taking it out, all went as expected.
Thanks for the help and attention.