libretro/scummvm
1
0
Fork 0
mirror of https://github.com/libretro/scummvm.git synced 2025-01-22 01:57:16 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

Add in alpha-blending code. Why? Because I can! :)

Browse Source 
svn-id: r4501
This commit is contained in:
James Brown 2002-07-09 12:33:09 +00:00
parent 0a9baabbdc
commit 78be337958
1 changed files with 61 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
newgui.cpp
View File

@ -27,6 +27,60 @@
#define hline(x, y, x2, color) line(x, y, x2, y, color);
#define vline(x, y, y2, color) line(x, y, x, y2, color);
// 8-bit alpha blending routines
int BlendCache[256][256];
int RGBMatch(byte *palette, int r, int g, int b) {
int i, bestidx = 0, besterr = 0xFFFFFF;
int error = 0;
for (i = 0;i < 256;i++) {
byte *pal = palette + (i * 3);
int r_diff = r - (int)*pal++;
int g_diff = g - (int)*pal++;
int b_diff = b - (int)*pal++;
r_diff *= r_diff; g_diff *= g_diff; b_diff *= b_diff;
error = r_diff + g_diff + b_diff;
if (error < besterr) {
besterr = error;
bestidx = i;
}
}
return bestidx;
}
int Blend(int src, int dst, byte *palette) {
int r, g, b, idx;
int alpha = 128; // Level of transparency [0-256]
byte *srcpal = palette + (dst * 3);
byte *dstpal = palette + (src * 3);
if (BlendCache[dst][src] > -1)
return BlendCache[dst][src];
r = (*srcpal++ * alpha);
r += (*dstpal++ * (256-alpha));
r /= 256;
g = (*srcpal++ * alpha);
g += (*dstpal++ * (256-alpha));
g /= 256;
b = (*srcpal++ * alpha);
b += (*dstpal++ * (256-alpha));
b /= 256;
return (BlendCache[dst][src] = RGBMatch(palette, r , g , b ));
}
void ClearBlendCache(byte *palette, int weight) {
for (int i = 0; i < 256; i++)
for (int j = 0 ; j < 256 ; j++)
// BlendCache[i][j] = i; // No alphablending
// BlendCache[i][j] = j; // 100% translucent
BlendCache[i][j] = -1; // Enable alphablending
}
/*
* TODO list
@ -42,7 +96,7 @@
NewGui::NewGui(Scumm *s) : _s(s), _need_redraw(false), _pauseDialog(0),
_saveLoadDialog(0), _aboutDialog(0), _optionsDialog(0)
{
{
}
void NewGui::pauseDialog()
@ -54,6 +108,7 @@ void NewGui::pauseDialog()
void NewGui::saveloadDialog()
{
ClearBlendCache(_s->_currentPalette, 128);
if (!_saveLoadDialog)
_saveLoadDialog = new SaveLoadDialog(this);
openDialog(_saveLoadDialog);
@ -249,8 +304,11 @@ void NewGui::fillArea(int x, int y, int w, int h, byte color)
return;
while (h--) {
for (int i = 0; i < w; i++)
ptr[i] = color;
for (int i = 0; i < w; i++) {
int srcc = ptr[i];
ptr[i] = Blend(srcc, color, _s->_currentPalette);
}
//ptr[i] = color;
ptr += 320;
}
}