mirror of
https://github.com/sehugg/8bitworkshop.git
synced 2024-08-19 01:28:56 +00:00
61 lines
1.6 KiB
C
61 lines
1.6 KiB
C
|
||
/*
|
||
Displays a bitmap using the TMS9928A's Mode 2.
|
||
|
||
In Mode 2, the screen is horizontally divided into three
|
||
256×64 pixel areas, each of which gets its own character
|
||
set. By sequentially printing the characters 0 through 255
|
||
in all three areas, the program can simulate a graphics mode
|
||
where each pixel can be set individually.
|
||
|
||
The limitation is that every horizontal run of 8 pixels
|
||
can only have two colors (a foreground and background color.)
|
||
|
||
The included Mode 2 bitmap was converted with a web utility:
|
||
http://msx.jannone.org/conv/
|
||
*/
|
||
|
||
#include <stdlib.h>
|
||
|
||
#include <cv.h>
|
||
#include <cvu.h>
|
||
|
||
#include "common.h"
|
||
|
||
/* link in MODE 2 bitmap data */
|
||
|
||
//#link "sailboat.s"
|
||
|
||
extern const unsigned char msx_bitmap[0x3807];
|
||
|
||
void setup_mode2() {
|
||
cvu_vmemset(0, 0, 0x4000);
|
||
cv_set_screen_mode(CV_SCREENMODE_BITMAP); // mode 2
|
||
cv_set_image_table(IMAGE);
|
||
cv_set_character_pattern_t(PATTERN|0x1fff); // AND mask
|
||
cv_set_color_table(COLOR|0x1fff); // AND mask
|
||
cv_set_sprite_attribute_table(SPRITES);
|
||
}
|
||
|
||
void main() {
|
||
// turn off screen
|
||
cv_set_screen_active(false);
|
||
// setup mode 2 grpahics
|
||
setup_mode2();
|
||
// copy pattern and color tables
|
||
cvu_memtovmemcpy(PATTERN, msx_bitmap+7, 0x1800);
|
||
cvu_memtovmemcpy(COLOR, msx_bitmap+7+COLOR, 0x1800);
|
||
// set IMAGE table to incrementing values
|
||
for (int i=0; i<0x300; i++) {
|
||
cvu_voutb(i, IMAGE+i);
|
||
}
|
||
// clear sprite table
|
||
cvu_vmemset(SPRITES, 0, 0x100);
|
||
// turn off screen
|
||
cv_set_screen_active(true);
|
||
while (1) {
|
||
//cv_set_character_pattern_t(PATTERN|rand()); // AND mask
|
||
//cv_set_color_table(COLOR|rand()); // AND mask
|
||
}
|
||
}
|