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Attempts more meaningful super high-res pixel output.

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With a timing hack as noted.
This commit is contained in:
Thomas Harte 2020-11-15 18:36:24 -05:00
parent 68ba73bee0
commit 1db713fec1
2 changed files with 46 additions and 9 deletions
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51
Machines/Apple/AppleIIgs/Video.cpp
View File

@ -22,9 +22,9 @@ constexpr auto FinalColumn = CyclesPerLine / CyclesPerTick;
// Converts from Apple's RGB ordering to this emulator's.
#if TARGET_RT_BIG_ENDIAN
#define PaletteConvulve(x) x
#define PaletteConvulve(x) uint16_t(x)
#else
#define PaletteConvulve(x) ((x&0xf00) >> 8) | ((x&0x0ff) << 8)
#define PaletteConvulve(x) uint16_t(((x&0xf00) >> 8) | ((x&0x0ff) << 8))
#endif
// The 12-bit values used by the Apple IIgs to approximate Apple II colours,
@ -178,6 +178,21 @@ void VideoBase::output_row(int row, int start, int end) {
if(start == start_of_pixels) {
// 640 is the absolute most number of pixels that might be generated
next_pixel_ = pixels_ = reinterpret_cast<uint16_t *>(crt_.begin_data(640, 2));
// YUCKY HACK. I do not know when the IIgs fetches its super high-res palette
// and control byte. Since I do not know, any guess is equally likely negatively
// to affect software. Therefore this hack is as good as any other guess:
// assume RAM has magical burst bandwidth, and fetch the whole set instantly.
// I could spread this stuff out to allow for real bandwidth, but it'd likely be
// no more accurate, while having less of an obvious I-HACKED-THIS red flag attached.
line_control_ = ram_[0x19d00 + row];
const int palette_base = (line_control_ & 15) * 16 + 0x19e00;
for(int c = 0; c < 16; c++) {
const int entry = ram_[palette_base + (c << 1)] | (ram_[palette_base + (c << 1) + 1] << 8);
palette_[c] = PaletteConvulve(entry);
}
// TODO: obey line_control_ & 0x40 interrupt control bit.
}
if(next_pixel_) {
@ -289,7 +304,7 @@ bool VideoBase::get_composite_is_colour() {
// MARK: - Outputters.
uint16_t *VideoBase::output_text(uint16_t *target, int start, int end, int row) const {
uint16_t row_address = get_row_address(row);
const uint16_t row_address = get_row_address(row);
for(int c = start; c < end; c++) {
const uint8_t source = ram_[row_address + c];
const int character = source & character_zones_[source >> 6].address_mask;
@ -311,12 +326,30 @@ uint16_t *VideoBase::output_text(uint16_t *target, int start, int end, int row)
return target;
}
uint16_t *VideoBase::output_super_high_res(uint16_t *target, int start, int end, int row [[maybe_unused]]) const {
for(int c = start; c < end; c++) {
// TODO!
target[0] = 0x0000;
target[1] = 0xffff;
target += 2;
uint16_t *VideoBase::output_super_high_res(uint16_t *target, int start, int end, int row) const {
// TODO: both the palette and the mode byte should have been fetched by now, and just be
// available. I haven't implemented that yet, so the below just tries to show _something_.
// The use of appleii_palette is complete nonsense, as is the assumption of two pixels per byte.
const int row_address = row * 160 + 0x12000;
// TODO: line_control_ & 0x20 should enable or disable colour fill mode.
if(line_control_ & 0x80) {
for(int c = start * 4; c < end * 4; c++) {
const uint8_t source = ram_[row_address + c];
target[0] = palette_[(source >> 6) & 0x3 + 0x8];
target[1] = palette_[(source >> 4) & 0x3 + 0xc];
target[2] = palette_[(source >> 2) & 0x3 + 0x0];
target[3] = palette_[(source >> 0) & 0x3 + 0x4];
target += 4;
}
} else {
for(int c = start * 4; c < end * 4; c++) {
const uint8_t source = ram_[row_address + c];
target[0] = palette_[(source >> 4) & 0xf];
target[1] = palette_[source & 0xf];
target += 2;
}
}
return target;

4
Machines/Apple/AppleIIgs/Video.hpp
View File

@ -80,6 +80,10 @@ class VideoBase: public Apple::II::VideoSwitches<Cycles> {
uint16_t *output_super_high_res(uint16_t *target, int start, int end, int row) const;
uint16_t *output_text(uint16_t *target, int start, int end, int row) const;
// Super high-res per-line state.
uint8_t line_control_;
uint16_t palette_[16];
};
class Video: public VideoBase {