dmm_display/common.cpp

#include "common.h"

#include <iostream>

using std::cout;
using std::endl;

bool init_sdl(SDL_Window **window)
{
	if (nullptr == window)
	{
		cout << "Nowhere to store window" << endl;
		return false;
	}

	// SDL Initialization
	if (SDL_Init(SDL_INIT_VIDEO) < 0)
	{
		cout << "SDL could not initialize! SDL - " << SDL_GetError() << endl;
		return false;
	}

	(*window) = SDL_CreateWindow("DMM Display",
		SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
		FONT_SIZE * 6, FONT_SIZE,
		SDL_WINDOW_SHOWN);
	if (nullptr == (*window))
	{
		cout << "Window could not be created! SDL - " << SDL_GetError() << endl;
		SDL_Quit();
		return false;
	}

	if (0 != TTF_Init())
	{
		cout << "Could not init TTF! SDL - "<< SDL_GetError() << endl;
		SDL_DestroyWindow(*window);
		SDL_Quit();
		return false;
	}

	return true;
}

void quit_sdl(SDL_Window *window)
{
	TTF_Quit();
	SDL_DestroyWindow(window);
	SDL_Quit();
}

bool check_quit()
{
	SDL_Event e;

	while(SDL_PollEvent(&e))
	{
		if (SDL_QUIT == e.type)
		{
			return true;
		}
	}

	return false;
}

void calc_text(std::string& text, std::vector<Reading>& readings)
{
	if (readings.empty())
	{
		return;
	}

	Reading last = *(readings.rbegin());
	text = "";

	if (last.is_neg)
	{
		text += '-';
	}
	else
	{
		text += ' ';
	}

	if (last.is_inf)
	{
		text += "  O L  ";
	}
	else
	{
		for (int i = 0; i < 4; ++i)
		{
			text += ('0' + last.value[i]);
			text += ' ';
		}
		text.erase(text.size() - 1);
	}

	if (last.dot_pos != 0)
	{
		text[last.dot_pos * 2] = '.';
	}

	switch (last.modifier)
	{
	case -9:
		text += 'n';
		break;

	case -6:
		text += "μ";
		break;

	case -3:
		text += 'm';
		break;

	case 0:
		text += ' ';
		break;

	case 3:
		text += 'k';
		break;

	case 6:
		text += 'M';
		break;

	default:
		text += ' ';
		break;
	}

	switch (last.type)
	{
	case Reading::reading_percent:
		text += "%  ";
		break;

	case Reading::reading_volts:
		text += "V  ";
		break;

	case Reading::reading_amps:
		text += "A  ";
		break;

	case Reading::reading_ohms:
		text += "Ω  ";
		break;

	case Reading::reading_hFE:
		text += "hFE";
		break;

	case Reading::reading_hertz:
		text += "Hz ";
		break;

	case Reading::reading_farads:
		text += "F  ";
		break;

	case Reading::reading_celsius:
		text += "°C ";
		break;

	case Reading::reading_fahrenheit:
		text += "°F ";
		break;

	default:
		text += "???";
		break;
	}
}

void draw_text(const std::string& text, SDL_Surface *surface, TTF_Font *font)
{
	SDL_Surface *txt_surface;
	SDL_Rect rect;
	SDL_Color fg;
	SDL_Color bg;

	fg.r = 0;
	fg.g = 0;
	fg.b = 0;

	bg.r = 255;
	bg.g = 255;
	bg.b = 255;

	if ((NULL == surface) || (NULL == font) || (0 == text.size()))
	{
		return;
	}

	txt_surface = TTF_RenderUTF8_Shaded(font, text.c_str(), fg, bg);

	rect.x = 0;
	rect.y = surface->h / 2 - txt_surface->h / 2;

	SDL_BlitSurface(txt_surface, NULL, surface, &rect);
	SDL_FreeSurface(txt_surface);
}