Rgb2Hires/Rgb2Hires_PC/src/Display.cpp
Christophe Meneboeuf ff08549ef1 Cleaning the code
2022-06-18 15:08:55 +02:00

324 lines
9.4 KiB
C++

/* Rgb2Hires
* Copyright (C) 2016-2022 Christophe Meneboeuf <christophe@xtof.info>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <filesystem>
#include <stdexcept>
#include <chrono>
#define SDL_MAIN_HANDLED
#include <SDL.h>
#include <SDL_image.h>
#include "Display.h"
using namespace std;
namespace Display
{
//! @brief Output the colors from a 14-dot block
void UpdateHiResRGBCell(const int x, const uint8_t* pLineAddr, ColorRgb* pOut);
std::unique_ptr<Screen> ComputeRgbBuffer(const uint8_t* hires);
Window* Window::S_pInstance = nullptr;
Window::~Window()
{
if (_pThread != nullptr) {
if (_pThread->joinable()) {
_stopFileSurvey.store(true);
_pThread->join();
}
delete _pThread;
}
if (_pTexture != nullptr) {
SDL_DestroyTexture(_pTexture);
}
if (_pRenderer != nullptr) {
SDL_DestroyRenderer(_pRenderer);
}
if (_pWindow != nullptr) {
SDL_DestroyWindow(_pWindow);
}
SDL_Quit();
}
Window* Window::GetInstance()
{
if (S_pInstance == nullptr) {
S_pInstance = new Window;
S_pInstance->init();
}
return S_pInstance;
}
bool Window::init()
{
// init
if (SDL_Init(SDL_INIT_VIDEO) != 0) {
sdlError("cannot initialise the preview window.");
}
SDL_SetHint(SDL_HINT_RENDER_SCALE_QUALITY, "0"); // nearest neighbor
// window
_pWindow = SDL_CreateWindow("Preview", SDL_WINDOWPOS_UNDEFINED,
SDL_WINDOWPOS_UNDEFINED,
560 * SCALE,
384 * SCALE,
SDL_WINDOW_SHOWN
);
if (_pWindow == nullptr) {
sdlError("cannot initialise the preview window.");
}
// renderer
_pRenderer = SDL_CreateRenderer(_pWindow, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);
if (_pRenderer == nullptr) {
sdlError("cannot initialise the preview window.");
}
// texture
_pTexture = SDL_CreateTexture(_pRenderer, SDL_PIXELFORMAT_BGR888, SDL_TEXTUREACCESS_STATIC, 560, 384);
if (_pTexture == nullptr) {
sdlError("cannot initialise the preview window.");
}
return true;
}
void Window::sdlError(const std::string& msg)
{
throw std::runtime_error{ "Error: " + msg };
}
void Window::display(const std::string& path, const uint8_t* hiresblob)
{
struct {
bool happened = false;
std::string what;
} error;
auto pViewport = ComputeRgbBuffer(hiresblob);
SDL_UpdateTexture(_pTexture, nullptr, pViewport->data(), sizeof(ColorRgb) * 560);
SDL_RenderClear(_pRenderer);
SDL_RenderCopy(_pRenderer, _pTexture, NULL, NULL);
SDL_RenderPresent(_pRenderer);
// launch thread to survey file modifications
_pThread = new std::thread( [this, &path, &pViewport, &error] // freed in ~Window()
{
auto timeModified = std::filesystem::last_write_time(path);
while (!this->_stopFileSurvey.load())
{
std::this_thread::sleep_for(std::chrono::milliseconds(100));
const bool isImgModified(timeModified != std::filesystem::last_write_time(path));
if (isImgModified)
{
bool isDone = false;
int nbErrors = 0;
std::vector<SDL_Surface*> surfaces;
while (!isDone) // several attempts as the file may be marked modified before being written
{
try
{
this_thread::sleep_for(std::chrono::milliseconds(500)); // 500ms between each attempt
// update hires image
SDL_Surface* surfaceRgb = IMG_Load(path.c_str());
surfaces.push_back(surfaceRgb);
if (surfaceRgb == nullptr)
{
throw("Cannot decode " + path);
}
const RgbToHires::ImageQuantized imageHiRes{ surfaceRgb };
// rgb conversion from hires data
std::lock_guard<std::mutex> lock{ this->_mutex }; // protecting pViewport
pViewport = ComputeRgbBuffer(imageHiRes.getHiresBuffer()->data());
isDone = true;
timeModified = std::filesystem::last_write_time(path);
this->_isFileModified.store(isImgModified);
}
catch (std::exception& e)
{
++nbErrors;
if (nbErrors >= 5) { // 5 atttemps
isDone = true;
error.happened = true;
error.what = e.what();
this->_stopFileSurvey.store(true);
}
}
}
for(auto surface : surfaces) { SDL_FreeSurface(surface); }
}
}
}); // thread
_pThread->detach();
// event loop
SDL_Event e;
while (true)
{
if (_isFileModified.load())
{
// update the display with rgb data
{
std::lock_guard<std::mutex> lock{ this->_mutex }; // protecting pViewport
SDL_UpdateTexture(_pTexture, nullptr, pViewport->data(), sizeof(ColorRgb) * 560);
}
SDL_RenderClear(_pRenderer);
SDL_RenderCopy(_pRenderer, _pTexture, NULL, NULL);
SDL_RenderPresent(_pRenderer);
}
if (SDL_WaitEventTimeout(&e, 100))
{
if (e.type == SDL_QUIT) { break; }
}
if (error.happened) {
throw std::runtime_error{ error.what };
}
}
}
constexpr std::array<ColorRgb, 7> Palette = {
BLACK,
WHITE,
BLUE,
ORANGE,
GREEN,
VIOLET,
BLACK // dummy
};
//===========================================================================
// RGB videocards HGR
//! @details Adapted from AppleWin: https://github.com/AppleWin/AppleWin
//! A 14-dot block is used to draw a 7-pixel block (2 * 3.5-pixel blocks)
//! Each dot of a 3.5-pixel block can be delayed so we draw on 2 subdots.
//! 28 subdots = 14 dots = 7 pixels (in 2 * 3.5-pixel blocks)
//! @param x Vertical position of the 14-dot block
//! @param pLineAddr pointer to the start of the line
//! @param pOut pointer to the 28-subdot block to draw
void UpdateHiResRGBCell(const int x, const uint8_t* pLineAddr, ColorRgb* pOut)
{
const int xpixel = x * 14;
int xoffset = x & 1; // offset to start of the 2 bytes
pLineAddr -= xoffset;
// We need all 28 bits because each pixel needs a three bit evaluation
uint8_t byteval1 = (x < 2 ? 0 : *(pLineAddr - 1));
uint8_t byteval2 = *pLineAddr;
uint8_t byteval3 = *(pLineAddr + 1);
uint8_t byteval4 = (x >= 38 ? 0 : *(pLineAddr + 2));
// all 28 bits chained
uint32_t dwordval = (byteval1 & 0x7F) | ((byteval2 & 0x7F) << 7) | ((byteval3 & 0x7F) << 14) | ((byteval4 & 0x7F) << 21);
// Extraction of 14 color pixels
ColorRgb colors[14];
int idxColor = 0;
uint32_t dwordval_tmp = dwordval;
dwordval_tmp = dwordval_tmp >> 7;
bool offset = (byteval2 & 0x80) ? true : false;
for (int i = 0; i < 14; i++)
{
if (i == 7) offset = (byteval3 & 0x80) ? true : false;
idxColor = dwordval_tmp & 0x3;
// Two cases because AppleWin's palette is in a strange order
if (offset)
colors[i] = Palette[1 + idxColor];
else
colors[i] = Palette[6 - idxColor];
if (i % 2) dwordval_tmp >>= 2;
}
// Black and White
ColorRgb bw[2];
bw[0] = Palette[0];
bw[1] = Palette[1];
constexpr uint32_t mask = 0x01C0; // 00|000001 1|1000000
constexpr uint32_t chck1 = 0x0140; // 00|000001 0|1000000
constexpr uint32_t chck2 = 0x0080; // 00|000000 1|0000000
// HIRES render in RGB works on a pixel-basis (1-bit data in framebuffer)
// The pixel can be 'color', if it makes a 101 or 010 pattern with the two neighbour bits
// In all other cases, it's black if 0 and white if 1
// The value of 'color' is defined on a 2-bits basis
if (xoffset)
{
// Second byte of the 14 pixels block
dwordval = dwordval >> 7;
xoffset = 7;
}
for (int i = xoffset; i < xoffset + 7; i++)
{
if (((dwordval & mask) == chck1) || ((dwordval & mask) == chck2))
{
// Color pixel
*(pOut) = colors[i];
*(pOut + 1) = *(pOut);
pOut += 2;
}
else
{
// B&W pixel
*(pOut) = bw[(dwordval & chck2 ? 1 : 0)];
*(pOut + 1) = *(pOut);
pOut += 2;
}
// Next pixel
dwordval = dwordval >> 1;
}
}
std::unique_ptr<Screen> ComputeRgbBuffer(const uint8_t* hires)
{
// Getting a RGB framebuffer
// Converting line per line, pixel-block per pixel-block
auto pViewport = make_unique<Screen>();
auto itLine = std::begin(*pViewport);
for (const auto lineBlockOffset : RgbToHires::LineAdresses)
{
for (const auto lineOffset : RgbToHires::LineOffsets)
{
const uint8_t* pHires = hires + lineBlockOffset + lineOffset; // interleaved HIRES source line
for (std::size_t x = 0; x < itLine->size(); ++x)
{
auto& block = (*itLine)[x];
UpdateHiResRGBCell(static_cast<int>(x), pHires++, block.data());
}
*(itLine + 1) = *itLine; // Doubling the destination lines
itLine += 2; // Next dest line
}
}
return pViewport;
}
}