Files
choco-chip8/DisplaySDL.cpp

85 lines
2.5 KiB
C++

#include "DisplaySDL.hpp"
#include "Peripherals.hpp"
#include <stdexcept>
DisplaySDL::DisplaySDL(int w, int h, uint32_t fgColor, uint32_t bgColor):
mpFramebuffer{std::make_unique<Framebuffer>()} {
// Create SDL Window
mpWindow = SDL_CreateWindow(
"ChocoChip-8",
SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED,
w, h,
0
);
if(mpWindow == NULL) {
throw std::runtime_error(SDL_GetError());
}
// Convert our foreground/background colors to the format expected by SDL
SDL_PixelFormat *fmt = SDL_AllocFormat(SDL_GetWindowPixelFormat(mpWindow));
mFgColor = SDL_MapRGB(
fmt,
(fgColor & 0x00FF0000) >> 16,
(fgColor & 0x0000FF00) >> 8,
(fgColor & 0x000000FF)
);
mBgColor = SDL_MapRGB(
fmt,
(bgColor & 0x00FF0000) >> 16,
(bgColor & 0x0000FF00) >> 8,
(bgColor & 0x000000FF)
);
SDL_FreeFormat(fmt);
};
DisplaySDL::~DisplaySDL() {
SDL_DestroyWindow(mpWindow);
}
void DisplaySDL::clear() {
for(auto &scanline : *mpFramebuffer) {
scanline.reset();
}
SDL_FillRect(SDL_GetWindowSurface(mpWindow), nullptr, mBgColor);
}
int DisplaySDL::blit(const chocochip8::Scanline &spriteScanline, int y) {
using chocochip8::Scanline;
Scanline &targetScanline = mpFramebuffer->at(y);
Scanline bitsToSet = spriteScanline & ~targetScanline;
Scanline bitsToReset = spriteScanline & targetScanline;
targetScanline ^= spriteScanline;
SDL_Surface *pSurface = SDL_GetWindowSurface(mpWindow);
SDL_Rect rect;
// Map framebuffer pixel to SDL surface rectangle
auto mapChipxelToPixel = [&rect, pSurface](int x, int y) {
// Note that the MSB of an scanline's bitset is the leftmost pixel.
x = (chocochip8::gcWidth - 1) - x;
int x1 = ( x * pSurface->w) / chocochip8::gcWidth;
int x2 = ((x + 1) * pSurface->w) / chocochip8::gcWidth;
int y1 = ( y * pSurface->h) / chocochip8::gcHeight;
int y2 = ((y + 1) * pSurface->h) / chocochip8::gcHeight;
rect.x = x1;
rect.y = y1;
rect.w = x2 - x1;
rect.h = y2 - y1;
};
for(int x = bitsToReset._Find_first(); x < bitsToReset.size(); x = bitsToReset._Find_next(x)) {
mapChipxelToPixel(x, y);
SDL_FillRect(pSurface, &rect, mBgColor);
}
for(int x = bitsToSet._Find_first(); x < bitsToSet.size(); x = bitsToSet._Find_next(x)) {
mapChipxelToPixel(x, y);
SDL_FillRect(pSurface, &rect, mFgColor);
}
return bitsToReset.any();
}
void DisplaySDL::updateWindow() const {
SDL_UpdateWindowSurface(mpWindow);
}