73 lines
2.3 KiB
C
73 lines
2.3 KiB
C
#include <pico/stdlib.h>
|
|
#include "common/config.h"
|
|
#include "vga/vgabuf.h"
|
|
#include "vga/render.h"
|
|
#include "vga/vgaout.h"
|
|
|
|
static inline uint_fast8_t char_terminal_bits(uint_fast8_t ch, uint_fast8_t glyph_line) {
|
|
uint_fast8_t bits = terminal_character_rom[((uint_fast16_t)ch << 3) | glyph_line];
|
|
if(ch & 0x80) {
|
|
// normal character
|
|
return bits & 0x7f;
|
|
}
|
|
|
|
if((bits & 0x80) == 0) {
|
|
// inverse character
|
|
return bits ^ 0x7f;
|
|
} else {
|
|
// flashing character
|
|
return (bits ^ text_flasher_mask) & 0x7f;
|
|
}
|
|
}
|
|
|
|
|
|
void DELAYED_COPY_CODE(render_terminal)() {
|
|
for(int line=0; line < 24; line++) {
|
|
render_terminal_line(line);
|
|
}
|
|
}
|
|
|
|
|
|
void DELAYED_COPY_CODE(render_terminal_line)(unsigned int line) {
|
|
const uint8_t *page = (const uint8_t *)terminal_memory;
|
|
const uint8_t *line_buf = page + (line * 80);
|
|
|
|
for(uint glyph_line=0; glyph_line < 8; glyph_line++) {
|
|
struct vga_scanline *sl = vga_prepare_scanline();
|
|
uint sl_pos = 0;
|
|
|
|
// Pad 40 pixels on the left to center horizontally
|
|
sl->data[sl_pos++] = (text_border|THEN_EXTEND_31) | ((text_border|THEN_EXTEND_7) << 16); // 16 pixels per word
|
|
|
|
for(uint col=0; col < 80; ) {
|
|
// Grab 14 pixels from the next two characters
|
|
uint32_t bits_a = char_terminal_bits(line_buf[col], glyph_line);
|
|
col++;
|
|
uint32_t bits_b = char_terminal_bits(line_buf[col], glyph_line);
|
|
col++;
|
|
|
|
uint32_t bits = (bits_a << 7) | bits_b;
|
|
|
|
// Translate each pair of bits into a pair of pixels
|
|
for(int i=0; i < 7; i++) {
|
|
uint32_t pixeldata = (bits & 0x2000) ? (text_fore) : (text_back);
|
|
pixeldata |= (bits & 0x1000) ?
|
|
(((uint32_t)text_fore) << 16) :
|
|
(((uint32_t)text_back) << 16);
|
|
bits <<= 2;
|
|
|
|
sl->data[sl_pos] = pixeldata;
|
|
sl_pos++;
|
|
}
|
|
}
|
|
|
|
// Pad 40 pixels on the right to center horizontally
|
|
sl->data[sl_pos++] = (text_border|THEN_EXTEND_31) | ((text_border|THEN_EXTEND_7) << 16); // 16 pixels per word
|
|
|
|
sl->length = sl_pos;
|
|
sl->repeat_count = 1;
|
|
vga_submit_scanline(sl);
|
|
}
|
|
}
|
|
|