static void __attribute__ ((optimize("-O3"))) refresh_screen(SDL_Surface *scr)
// uses global line + vga_odd
{
uint16_t *dst = (uint16_t*)scr->pixels;
draw_buffer = mybuffer1;
graph_frame();
for (vga_line=0;vga_line<screen_height;vga_line++) {
vga_odd=0;
graph_line(); // using line, updating draw_buffer ...
#ifdef VGA_SKIPLINE
vga_odd=1; graph_line(); // a second time for SKIPLINE modes
#endif
// copy to screen at this position (cheating)
uint16_t *src = (uint16_t*) draw_buffer;
for (int i=0;i<screen_width;i++)
*dst++= pixelconv(*src++);
// swap lines buffers to simulate double line buffering
draw_buffer = (draw_buffer == &mybuffer1[0] ) ? &mybuffer2[0] : &mybuffer1[0];
}
}
static void refresh_screen()
// uses global line + vga_odd
{
draw_buffer = mybuffer1;
for (vga_line=0;vga_line<VGA_V_PIXELS;vga_line++) {
#ifdef VGA_SKIPLINE
vga_odd=0;
graph_line(); // using line, updating draw_buffer ...
vga_odd=1;
graph_line(); // a second time for SKIPLINE modes
#else
graph_line(); // a second time for SKIPLINE modes
#endif
// swap lines buffers to simulate double line buffering
draw_buffer = (draw_buffer == &mybuffer1[0] ) ? &mybuffer2[0] : &mybuffer1[0];
}
for (;vga_line<VGA_V_PIXELS+VGA_V_SYNC;vga_line++) {
#ifdef VGA_SKIPLINE
vga_odd=0;
graph_vsync(); // using line, updating draw_buffer ...
vga_odd=1;
graph_vsync(); // a second time for SKIPLINE modes
#else
graph_vsync(); // once
#endif
}
}
static void refresh_screen()
// uses global line + vga_odd
{
draw_buffer = mybuffer1;
graph_frame();
for (vga_line=0;vga_line<screen_height;vga_line++) {
vga_odd=0;
graph_line(); // using line, updating draw_buffer ...
#ifdef VGA_SKIPLINE
vga_odd=1; graph_line(); // a second time for SKIPLINE modes
#endif
// swap lines buffers to simulate double line buffering
draw_buffer = (draw_buffer == &mybuffer1[0] ) ? &mybuffer2[0] : &mybuffer1[0];
}
}
static void __attribute__ ((optimize("-O3"))) refresh_screen (SDL_Surface *scr)
// uses global line + vga_odd, scale two times
{
uint32_t * restrict dst = (uint32_t*)scr->pixels; // will render 2 pixels at a time horizontally
draw_buffer = mybuffer1; // currently 16bit data
for (vga_line=0;vga_line<screen_height;vga_line++) {
#ifdef VGA_SKIPLINE
vga_odd=0;
graph_line(); // using line, updating draw_buffer ...
#if VGA_BPP==8
expand_buffer();
#endif
vga_odd=1;
graph_line(); // a second time for SKIPLINE modes
#if VGA_BPP==8
expand_buffer();
#endif
#else
graph_line();
#if VGA_BPP==8
expand_buffer();
#endif
#endif
// copy to screen at this position
uint16_t *restrict src = (uint16_t*) draw_buffer;
switch (scale) {
case 1 :
// copy to screen at this position (cheating)
for (int i=0;i<screen_width;i++)
*dst++= pixelconv32(*src++);
break;
case 2 :
for (int i=0;i<screen_width;i++, dst+=2) {
uint32_t pix = pixelconv32(*src++);
*dst = pix; // blit line
*(dst+1) = pix; // blit line
*(dst+scr->pitch/sizeof(uint32_t))=pix; // also next line
*(dst+scr->pitch/sizeof(uint32_t)+1)=pix; // also next line
}
dst += scr->pitch/sizeof(uint32_t); // we already drew the line after, skip it
break;
}
// swap lines buffers to simulate double line buffering
draw_buffer = ( draw_buffer == &mybuffer1[0] ) ? &mybuffer2[0] : &mybuffer1[0];
}
for (;vga_line<screen_height+VSYNC_LINES;vga_line++) {
#ifdef VGA_SKIPLINE
vga_odd=0;
graph_vsync(); // using line, updating draw_buffer ...
vga_odd=1;
graph_vsync(); // a second time for SKIPLINE modes
#else
graph_vsync(); // once
#endif
}
}
// HSYNC interrupt handler
void __attribute__ ((used)) TIM3_IRQHandler(void) // attribute used neded if called from ASM
{
TIM3->SR=0; // clear status
// only double-line modes on micro
vga_line+=vga_odd;
vga_odd=1-vga_odd;
// starting from line #1, line #0 already in drawbuffer
if (vga_line < VGA_V_PIXELS) {
if (!vga_odd)
// swap display & draw buffers, effectively draws line-1. does not swap on odd lines if not needed
{
uint8_t *t;
t=display_buffer;
display_buffer = draw_buffer;
draw_buffer = t;
}
if (vga_line>0) // This doesn't happen only when we just set up vga_line=0 and now vga_odd=1
prepare_pixel_DMA(); // will be triggered after
#ifdef PROFILE
line_time = DWT->CYCCNT; // reset the perf counter
#endif
graph_line(); // Game graph callback !
draw_buffer[0]=0;
#ifdef PROFILE
line_time = DWT->CYCCNT - line_time; // read the counter
line_time /= VGA_PIXELCLOCK; // scale it to screen width
// plot from 0 to VGA_V_PIXELS a green or red element
uint8_t c=0b11001; //green
if (line_time>VGA_H_PIXELS) // start over but red
{
line_time-=VGA_H_PIXELS;
c=0b11100000; // red
}
draw_buffer[line_time-1]=0;
draw_buffer[line_time]=c;
draw_buffer[line_time+1]=0;
#endif
} else {
graph_vsync(); // always call, odd or not
if (!vga_odd) // only once
{
if (vga_line== VGA_V_PIXELS) {
vga_frame++; // new frame sync now.
} else if (vga_line==VGA_V_PIXELS+1) {
#ifndef NO_AUDIO
audio_frame();
#endif
} else if (vga_line==VGA_V_PIXELS+VGA_V_FRONTPORCH+1) {
GPIOB->BSRRH |= GPIO_BSRR_BS_15; // lower VSync line
} else if(vga_line==VGA_V_PIXELS+1+VGA_V_FRONTPORCH+VGA_V_SYNC) {
GPIOB->BSRRL |= GPIO_BSRR_BS_15; // raise VSync line
}
}
if(vga_line==VGA_V_PIXELS+VGA_V_FRONTPORCH+VGA_V_SYNC+VGA_V_BACKPORCH+1) {
vga_line=0;
graph_line(); // first line next frame!
}
}
// audio generation each vga line
#ifndef NO_AUDIO
audio_line();
#endif
}
void __attribute__ ((used)) TIM5_IRQHandler() // Hsync Handler
{
TIM5->SR=0; // clear pending interrupts
#ifdef VGA_SKIPLINE
vga_line+=vga_odd;
vga_odd=1-vga_odd;
#else
vga_line++;
#endif
// starting from line #1, line #0 already in drawbuffer
if (vga_line < VGA_V_PIXELS) {
#ifdef VGA_SKIPLINE
if (!vga_odd)
#endif
// swap display & draw buffers, effectively draws line-1
{
pixel_t *t;
t=display_buffer;
display_buffer = draw_buffer;
draw_buffer = t;
}
#ifdef VGA_SKIPLINE
if (vga_line>0) // This doesn't happens only when we just set up vga_line=0 and now vga_odd=1
#endif
prepare_pixel_DMA(); // will be triggered
#ifdef PROFILE
line_time = DWT->CYCCNT; // reset the perf counter
#endif
graph_line(); // Game callback !
#if VGA_BPP==8
expand_drawbuffer();
#endif
#ifdef PROFILE
line_time = DWT->CYCCNT - line_time; // read the counter
line_time /= VGA_PIXELCLOCK; // scale it to screen width
// plot from 0 to VGA_V_PIXELS a green or red element
uint16_t c=0b1111100000; //green
if (line_time>VGA_H_PIXELS) // start over but red
{
line_time-=VGA_H_PIXELS;
c=0b111110000000000; // red
}
draw_buffer[line_time-1]=0;
draw_buffer[line_time]=c;
draw_buffer[line_time+1]=0;
#endif
} else {
graph_vsync(); // always call, odd or not
if (!vga_odd) {
if (vga_line == VGA_V_PIXELS) {
vga_frame++; // new frame sync starts just at vsync.
}
if (vga_line==VGA_V_PIXELS+VGA_V_FRONTPORCH+1) {
GPIOA->BSRRH |= GPIO_BSRR_BS_0; // raise VSync line
} else if(vga_line==VGA_V_PIXELS+1+VGA_V_FRONTPORCH+VGA_V_SYNC) {
GPIOA->BSRRL |= GPIO_BSRR_BS_0; // raise VSync line
} else if(vga_line==VGA_V_PIXELS+VGA_V_FRONTPORCH+VGA_V_SYNC+VGA_V_BACKPORCH) {
vga_line=0; // we're on vga_odd=0, next time will be a vga_odd=1 and vga_line=0
graph_line(); // first line next frame!
}
}
}
}
