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ADL: Refactor graphics code
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@waltervn
waltervn committed Mar 9, 2016
1 parent f5430f9 commit 50d6e69
Showing 1 changed file with 84 additions and 71 deletions.
155 changes: 84 additions & 71 deletions engines/adl/display.cpp
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Expand Up @@ -52,6 +52,12 @@ const byte colorPalette[COLOR_PALETTE_ENTRIES * 3] = {
0xf2, 0x5e, 0x00
};

// Corresponding color in second palette
#define PAL2(X) ((X) | 0x04)

// Alternate color for odd pixel rows (for scanlines)
#define ALTCOL(X) ((X) | 0x08)

// Green monochrome palette
#define MONO_PALETTE_ENTRIES 2
const byte monoPalette[MONO_PALETTE_ENTRIES * 3] = {
Expand Down Expand Up @@ -294,6 +300,17 @@ void Display::showScanlines(bool enable) {
}
}

static void copyEvenSurfaceRows(Graphics::Surface &surf) {
byte *src = (byte *)surf.getPixels();

for (uint y = 0; y < surf.h / 2; ++y) {
byte *dst = src + surf.pitch;
for (uint x = 0; x < surf.w; ++x)
dst[x] = ALTCOL(src[x]);
src += surf.pitch * 2;
}
}

void Display::updateHiResSurface() {
byte *src = _frameBuf;
byte *dst = (byte *)_frameBufSurface->getPixels();
Expand All @@ -303,68 +320,78 @@ void Display::updateHiResSurface() {
src += DISPLAY_PITCH;
dst += _frameBufSurface->pitch * 2;
}

copyEvenSurfaceRows(*_frameBufSurface);
}

void Display::decodeScanlineColor(byte *dst, int pitch, byte *src) const {
bool prevOn = false;
static inline byte processColorBits(uint16 &bits, bool &odd, bool secondPal) {
byte color = 0;

switch (bits & 0x7) {
case 0x3: // 011 (white)
case 0x6: // 110
case 0x7: // 111
color = 1;
break;
case 0x2: // 010 (color)
color = 2 + odd;
break;
case 0x5: // 101 (color)
color = 2 + !odd;
}

if (src[0] & 0x80)
dst++;
if (secondPal)
color = PAL2(color);

for (uint j = 0; j < 40; ++j) {
bool secondPal = src[j] & 0x80;
byte cur = src[j];
byte next = 0;
if (j != 39)
next = src[j + 1];
odd = !odd;
bits >>= 1;

for (uint k = 0; k < 7; ++k) {
bool curOn = cur & (1 << k);
bool nextOn;
return color;
}

if (k != 6)
nextOn = cur & (1 << (k + 1));
else
nextOn = next & 1;
void Display::decodeScanlineColor(byte *dst, int pitch, byte *src) const {
uint16 bits = (src[0] & 0x7f) << 1;
byte pal = src[0] >> 7;

byte color;
if (curOn == prevOn || curOn == nextOn)
color = curOn ? 1 : 0;
else
color = (curOn == ((j + k) % 2) ? 3 : 2);
if (pal != 0)
*dst++ = 0;

if (secondPal)
color |= 4;
bool odd = false;

dst[0] = color;
dst[pitch] = color + COLOR_PALETTE_ENTRIES;
++dst;

if (k == 6) {
if (secondPal) {
if (next & 0x80) {
dst[0] = color;
dst[pitch] = color + COLOR_PALETTE_ENTRIES;
++dst;
}
} else {
dst[0] = color;
dst[pitch] = color + COLOR_PALETTE_ENTRIES;
++dst;
if (next & 0x80) {
dst[0] = color | 4;
dst[pitch] = (color | 4) + COLOR_PALETTE_ENTRIES;
++dst;
}
}
} else {
dst[0] = color;
dst[pitch] = color + COLOR_PALETTE_ENTRIES;
++dst;
}
for (uint i = 0; i < 40; ++i) {
if (i != 39) {
bits |= (src[i + 1] & 0x7f) << 8;
pal |= (src[i + 1] >> 7) << 1;
}

prevOn = curOn;
// For the first 6 bits in the block we draw two pixels
for (uint j = 0; j < 6; ++j) {
byte color = processColorBits(bits, odd, pal & 1);
*dst++ = color;
*dst++ = color;
}

// Last bit of the block, draw one, two or three pixels
byte color = processColorBits(bits, odd, pal & 1);

// Draw the first pixel
*dst++ = color;

switch (pal) {
case 0x0:
case 0x3:
// If palette stays the same, draw a second pixel
*dst++ = color;
break;
case 0x2:
// If we're moving from first to second palette,
// draw a second pixel, and a third in the second
// palette.
*dst++ = color;
*dst++ = PAL2(color);
}

pal >>= 1;
}
}

Expand Down Expand Up @@ -420,21 +447,10 @@ void Display::drawChar(byte c, int x, int y) {
byte *buf = (byte *)_font->getPixels() + y * _font->pitch + x;

for (uint row = 0; row < 8; ++row) {
if (row & 1) {
buf[_font->pitch] = COLOR_PALETTE_ENTRIES;
buf[_font->pitch + 1] = COLOR_PALETTE_ENTRIES;
buf[_font->pitch + 6 * 2] = COLOR_PALETTE_ENTRIES;
buf[_font->pitch + 6 * 2 + 1] = COLOR_PALETTE_ENTRIES;
}
for (uint col = 1; col < 6; ++col) {
if (font[c][col - 1] & (1 << row)) {
buf[col * 2] = 1;
buf[col * 2 + 1] = 1;
buf[_font->pitch + col * 2] = 1 + COLOR_PALETTE_ENTRIES;
buf[_font->pitch + col * 2 + 1] = 1 + COLOR_PALETTE_ENTRIES;
} else {
buf[_font->pitch + col * 2] = COLOR_PALETTE_ENTRIES;
buf[_font->pitch + col * 2 + 1] = COLOR_PALETTE_ENTRIES;
}
}

Expand All @@ -458,21 +474,18 @@ void Display::createFont() {
for (uint col = 0; col < _font->w; ++col)
bufInv[col] = (buf[col] ? 0 : 1);

buf += _font->pitch;
bufInv += _font->pitch;

for (uint col = 0; col < _font->w; ++col)
bufInv[col] = (buf[col] == COLOR_PALETTE_ENTRIES + 1 ? COLOR_PALETTE_ENTRIES : COLOR_PALETTE_ENTRIES + 1);

buf += _font->pitch;
bufInv += _font->pitch;
buf += _font->pitch * 2;
bufInv += _font->pitch * 2;
}

copyEvenSurfaceRows(*_font);
}

void Display::scrollUp() {
memmove(_textBuf, _textBuf + 40, kTextBufSize - 40);
memset(_textBuf + kTextBufSize - 40, APPLECHAR(' '), 40);
_cursorPos -= 40;
if (_cursorPos >= 40)
_cursorPos -= 40;
}

} // End of namespace Adl

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