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Bitmap and multicolor modes
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@Two9A
Two9A committed Jan 26, 2015
1 parent 38b5c96 commit 4398b94
Showing 1 changed file with 133 additions and 11 deletions.
144 changes: 133 additions & 11 deletions js/c64/vic.js
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Expand Up @@ -243,7 +243,7 @@ define(function() {
renderPixels: function(pixels, skipFrames) {
var i = 0, j, k, p;
var x = 0, y = 0, pos = 0, row = 0, loc = 0;
var sx, cx, px, py, pixel, mode = 0, badline,
var sx, cx, px, py, pixel, pixmode, mode = 0, badline,
left_border, right_border,
left_hbl = this.sizes.HBLL,
right_hbl = this.sizes.RASTER_LENGTH - this.sizes.HBLR,
Expand Down Expand Up @@ -381,7 +381,7 @@ define(function() {
pixel = this.BORDER;
} else {
// Background
pixel = this.BG0;
pixel = -1;

// Sprites wot live below the text
for (j = 7; j >= 0; j--) {
Expand All @@ -404,15 +404,132 @@ define(function() {
}

// Text
j = this.r(this.IDLE
? 0x3FFF
: (charBase + this.curLineScr[sx >> 3] * 8 + this.RC)
);
if (
(y >= top_border && y < bottom_border) &&
(j & this.bitPositions[cx])
) {
pixel = this.curLineCol[sx >> 3];
if (y >= top_border && y < bottom_border) {
pixmode =
(this.EXTCOLOR ? 4 : 0) |
(this.HIRES ? 2 : 0) |
(this.MULTICOLOR ? 1 : 0);
switch (pixmode) {
case 0:
// Standard text mode
j = this.r(this.IDLE
? 0x3FFF
: (charBase + this.curLineScr[sx >> 3] * 8 + this.RC)
);
if (j & this.bitPositions[cx]) {
pixel = this.curLineCol[sx >> 3];
} else if (pixel == -1) {
pixel = this.BG0;
}
break;

case 1:
// Multicolor text mode
j = this.r(this.IDLE
? 0x3FFF
: (charBase + this.curLineScr[sx >> 3] * 8 + this.RC)
);
if (this.curLineCol[sx >> 3] & 8) {
cx &= 6;
k = ((j & this.bitPositions[cx]) ? 2 : 0) |
((j & this.bitPositions[cx+1]) ? 1 : 0);
if (k == 3) {
pixel = this.curLineCol[sx >> 3] & 7;
} else if (pixel == -1) {
switch (k) {
case 0:
pixel = this.BG0;
break;
case 1:
pixel = this.BG1;
break;
case 2:
pixel = this.BG2;
break;
}
}
} else {
if (j & this.bitPositions[cx]) {
pixel = this.curLineCol[sx >> 3] & 7;
} else if (pixel == -1) {
pixel = this.BG0;
}
}
break;

case 2:
// Bitmap mode
j = this.r(this.IDLE
? 0x3FFF
: ((charBase & 8192) + (this.VC * 8) + this.RC)
);
pixel = this.curLineScr[sx >> 3];
if (j & this.bitPositions[cx]) {
pixel >>= 4;
}
pixel &= 15;
break;

case 3:
// Multicolor bitmap mode
j = this.r(this.IDLE
? 0x3FFF
: ((charBase & 8192) + (this.VC * 8) + this.RC)
);
cx &= 6;
k = ((j & this.bitPositions[cx]) ? 2 : 0) |
((j & this.bitPositions[cx+1]) ? 1 : 0);
switch (k) {
case 0:
if (pixel == -1) {
pixel = this.BG0;
}
break;
case 1:
pixel = this.curLineScr[sx >> 3] >> 4;
break;
case 2:
pixel = this.curLineScr[sx >> 3];
break;
case 3:
pixel = this.curLineCol[sx >> 3];
break;
}
pixel &= 15;
break;

case 4:
// Extended-color text mode
j = this.r(this.IDLE
? 0x3FFF
: (charBase + (this.curLineScr[sx >> 3] & 63) * 8 + this.RC)
);
if (j & this.bitPositions[cx]) {
pixel = this.curLineCol[sx >> 3];
} else if (pixel == -1) {
switch (this.curLineScr[sx >> 3] & 192) {
case 0:
pixel = this.BG0;
break;
case 64:
pixel = this.BG1;
break;
case 128:
pixel = this.BG2;
break;
case 192:
pixel = this.BG3;
break;
}
}
break;

// Cases 5, 6, 7 are invalid modes
case 5:
case 6:
case 7:
break;
}
}

// Sprites above the text
Expand All @@ -438,6 +555,11 @@ define(function() {
break;
}

if (pixel == -1) {
// Rendering failed, probably an invalid mode
pixel = 0;
}

pixel = this.colors[0 | pixel];
imageData.data[pos++] = pixel[0];
imageData.data[pos++] = pixel[1];
Expand Down

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