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Take a first shot at magical instant blitting.

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This commit is contained in:
Thomas Harte 2021-09-23 18:13:51 -04:00
parent 60bad22a91
commit ab69fe56c9
2 changed files with 39 additions and 3 deletions
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36
Machines/Amiga/Blitter.cpp
View File

@ -8,6 +8,8 @@
#include "Blitter.hpp"
#include "Minterms.h"
//#define NDEBUG
#define LOG_PREFIX "[Blitter] "
#include "../../Outputs/Log.hpp"
@ -36,6 +38,10 @@ void Blitter::set_size(uint16_t value) {
width_ = (width_ & ~0x3f) | (value & 0x3f);
height_ = (height_ & ~0x3ff) | (value >> 6);
LOG("Set size to " << std::dec << width_ << ", " << height_);
// Current assumption: writing this register informs the
// blitter that it should treat itself as about to start a new line.
a_ = b_ = 0;
}
void Blitter::set_minterms(uint16_t value) {
@ -53,6 +59,7 @@ void Blitter::set_horizontal_size(uint16_t value) {
void Blitter::set_modulo(int channel, uint16_t value) {
LOG("Set modulo size " << channel << " to " << PADHEX(4) << value);
modulos_[channel] = value;
}
void Blitter::set_data(int channel, uint16_t value) {
@ -114,12 +121,39 @@ bool Blitter::advance() {
printf("!!! Line %08x\n", pointer_[3]);
// ram_[pointer_[3] & ram_mask_] = 0x0001 << shifts_[0];
ram_[pointer_[3] & ram_mask_] = 0xffff;
} else {
// Copy mode.
printf("!!! Copy %08x\n", pointer_[3]);
ram_[pointer_[3] & ram_mask_] = 0x8000;
// Quick hack: do the entire action atomically. Isn't life fabulous?
for(int y = 0; y < height_; y++) {
for(int x = 0; x < width_; x++) {
a_ = (a_ << 16) | ram_[pointer_[0] & ram_mask_];
b_ = (b_ << 16) | ram_[pointer_[1] & ram_mask_];
const uint16_t c = ram_[pointer_[2] & ram_mask_];
ram_[pointer_[3] & ram_mask_] =
apply_minterm(
uint16_t(a_ >> shifts_[0]),
uint16_t(b_ >> shifts_[1]),
c,
minterms_);
++pointer_[0];
++pointer_[1];
++pointer_[2];
++pointer_[3];
}
pointer_[0] += modulos_[0];
pointer_[1] += modulos_[1];
pointer_[2] += modulos_[2];
pointer_[3] += modulos_[3];
}
}
ram_[pointer_[3] & ram_mask_] = 0xffff;
height_ = 0;
return true;

6
Machines/Amiga/Blitter.hpp
View File

@ -41,10 +41,12 @@ class Blitter: public DMADevice<4> {
bool advance();
private:
uint8_t minterms_;
uint8_t minterms_ = 0;
int width_ = 0, height_ = 0;
uint32_t a_ = 0, b_ = 0;
uint16_t modulos_[4]{};
int shifts_[2];
int shifts_[2]{};
bool line_mode_ = false;
};