bool SetBlender(BlendMode blend_mode, bool dst_has_alpha, bool src_has_alpha, int blend_alpha)
{
if (blend_mode < 0 || blend_mode > kNumBlendModes)
return false;
const BlendModeSetter &set = BlendModeSets[blend_mode];
PfnBlenderCb blender;
if (dst_has_alpha)
blender = src_has_alpha ? set.AllAlpha :
(blend_alpha == 0xFF ? set.OpaqueToAlphaNoTrans : set.OpaqueToAlpha);
else
blender = src_has_alpha ? set.AlphaToOpaque : set.AllOpaque;
if (blender)
{
set_blender_mode(nullptr, nullptr, blender, 0, 0, 0, blend_alpha);
return true;
}
return false;
}
void ALSoftwareGraphicsDriver::RenderToBackBuffer()
{
for (int i = 0; i < numToDraw; i++)
{
if (drawlist[i] == NULL)
{
if (_nullSpriteCallback)
_nullSpriteCallback(drawx[i], drawy[i]);
else
throw Ali3DException("Unhandled attempt to draw null sprite");
continue;
}
ALSoftwareBitmap* bitmap = drawlist[i];
int drawAtX = drawx[i];// + x;
int drawAtY = drawy[i];// + y;
if ((bitmap->_opaque) && (bitmap->_bmp == virtualScreen))
{ }
else if (bitmap->_opaque)
{
blit(bitmap->_bmp, virtualScreen, 0, 0, drawAtX, drawAtY, bitmap->_bmp->w, bitmap->_bmp->h);
}
else if (bitmap->_transparency >= 255)
{
// fully transparent... invisible, do nothing
}
else if (bitmap->_hasAlpha)
{
if (bitmap->_transparency == 0)
set_alpha_blender();
else
set_blender_mode(NULL, NULL, _trans_alpha_blender32, 0, 0, 0, bitmap->_transparency);
draw_trans_sprite(virtualScreen, bitmap->_bmp, drawAtX, drawAtY);
}
else
{
draw_sprite_with_transparency(bitmap->_bmp, drawAtX, drawAtY, bitmap->_transparency);
}
}
if (((_tint_red > 0) || (_tint_green > 0) || (_tint_blue > 0))
&& (_colorDepth > 8)) {
// screen tint
// This slows down the game no end, only experimental ATM
set_trans_blender(_tint_red, _tint_green, _tint_blue, 0);
draw_lit_sprite(virtualScreen, virtualScreen, 0, 0, 128);
/* This alternate method gives the correct (D3D-style) result, but is just too slow!
if ((_spareTintingScreen != NULL) &&
((_spareTintingScreen->w != virtualScreen->w) || (_spareTintingScreen->h != virtualScreen->h)))
{
destroy_bitmap(_spareTintingScreen);
_spareTintingScreen = NULL;
}
if (_spareTintingScreen == NULL)
{
_spareTintingScreen = create_bitmap_ex(bitmap_color_depth(virtualScreen), virtualScreen->w, virtualScreen->h);
}
tint_image(virtualScreen, _spareTintingScreen, _tint_red, _tint_green, _tint_blue, 100, 255);
blit(_spareTintingScreen, virtualScreen, 0, 0, 0, 0, _spareTintingScreen->w, _spareTintingScreen->h);*/
}
ClearDrawList();
}