void Image::draw()
{
printf("Image::draw called\n");
for (int i = 0; i < m_height; i++)
drawScanline(i);
glFlush();
}
void updateGraphicsTest(struct gameboy * gameboy)
{
//fill a frame buffer with some simple pixel data and see if it draws correctly
setLCDStatus(gameboy);
uint8_t previousMode = getCurrentMode(gameboy);
requestAnyNewModeInterrupts(gameboy, previousMode);
if (isLCDEnabled(gameboy)){
gameboy->screen.scanlineCounter += gameboy->cpu.previousInstruction.cycles;
}
else {
return;
}
if (gameboy->screen.scanlineCounter >= SCANLINE_CYCLE_TIME){
gameboy->screen.currentScanline++;
gameboy->screen.scanlineCounter = 0;
if (gameboy->screen.currentScanline == Y){
requestInterrupt(gameboy, int_vblank);
//printf("start vblank\n");
}
else if (gameboy->screen.currentScanline > (Y + NO_OF_INVISIBLE_SCANLINES)){
gameboy->screen.currentScanline = 0;
//printf("resetting scanline\n");
}
else if (gameboy->screen.currentScanline < Y){
// printf("drawing scanline %d\n", gameboy->screen.currentScanline);
drawScanline(gameboy);
}
else {
//printf("In vblank\n");
}
}
}
void Image::drawScanlines(int yMin, int yMax)
{
for (int i = yMin; i < yMax; i++)
{
drawScanline(i);
}
}
void
Canvas::drawTriangle(const Vertex &v1, const Vertex &v2, const Vertex &v3, const Texture *texture) {
// sort a b c by y, top to bottom
const Vertex *a = &v1;
const Vertex *b = &v2;
const Vertex *c = &v3;
if (a->position.y > b->position.y) {
std::swap(a, b);
}
if (b->position.y > c->position.y) {
std::swap(b, c);
}
if (a->position.y > b->position.y) {
std::swap(a, b);
}
float middleFactor = (float)(b->position.y - a->position.y) / (c->position.y - a->position.y);
Vertex middle = a->interpolate(*c, middleFactor);
int startY = a->position.y;
int endY = b->position.y;
for (int y = startY; y <= endY; ++y) {
float factor = 0;
if (endY != startY) {
factor = (float)(y - startY) / (endY - startY);
}
Vertex va = a->interpolate(*b, factor);
Vertex vb = a->interpolate(middle, factor);
drawScanline(va, vb, y, texture);
}
startY = b->position.y;
endY = c->position.y;
for (int y = startY; y <= endY; ++y) {
float factor = 0;
if (endY != startY) {
factor = (float)(y - startY) / (endY - startY);
}
Vertex va = b->interpolate(*c, factor);
Vertex vb = middle.interpolate(*c, factor);
drawScanline(va, vb, y, texture);
}
}
static void handleCurrentScanline(struct gameboy * gameboy)
{
uint8_t currentScanline = gameboy->screen.currentScanline;
if (currentScanline == Y){
requestInterrupt(gameboy, int_vblank);
}
else if (currentScanline > (Y + NO_OF_INVISIBLE_SCANLINES)){
gameboy->screen.currentScanline = 0; //reset
}
else {
drawScanline(gameboy);
}
}
void Image::draw()
{
for (int i = 0; i < m_height; i++)
drawScanline(i);
}
//update lcdstatus
INLINE void updateLCDStatus(int cycles){
STAT |= 0x80;
//lcd enabled
if (LCDC&0x80){
gbcpu.lcd->scanlinecyclecounter -= cycles;
//setting modes and requesting interrupts when switching
if(LY>=144){
//set mode to 1
STAT=(STAT&0xFC) | 0x1;
}else{
int previousmode = STAT & 0x3;
int requestinterrupt = 0;
if (gbcpu.lcd->scanlinecyclecounter >= 376)
{
//set mode to 2 (OAM-RAM search)
STAT=(STAT&0xFC) | 0x2;
requestinterrupt = STAT & 0x20;
}
else if(gbcpu.lcd->scanlinecyclecounter >= 204)
{
//set mode to 3 (Data Transfer)
STAT=(STAT&0xFC) | 0x3;
}
else
{
//set to mode 0 (H-Blank)
STAT&=0xFC;
requestinterrupt = STAT & 0x8;
}
//request interrupt when mode changed for the 1st time
if (requestinterrupt && (previousmode != (STAT & 0x3)))
interruptZ80(I_LCD_STAT);
}
//move to next scanline
if (gbcpu.lcd->scanlinecyclecounter <=0)
{
LY+=1;
gbcpu.lcd->scanlinecyclecounter=456;
//starting vsync period
if (LY==144){
//request vblank
interruptZ80(I_V_BLANK);
//set mode to 1
STAT=(STAT&0xFC) | 0x1;
return;
}
if(LY <144){
drawScanline();
}
LY=LY%154;
}
LY_LYC();
}else{
//set mode to 0
STAT=(STAT&0xF8);
//reset counter
gbcpu.lcd->scanlinecyclecounter=456;
//reset LY
LY=0;
}
}
