z80/zx_ula.cpp

#include "zx_ula.h"
#include <SDL2/SDL.h>

namespace zx_ula
{
    static uint8_t border_color = 0;
    static uint8_t ear = 0;
    static uint8_t mic = 0;

    int port_in(int port)
    {
        const uint8_t *keys = SDL_GetKeyboardState(NULL);
        const uint8_t h_addr = (port>>8);
        uint8_t result = 0xff;
        if (!(h_addr & ~0xfe))
        {
            result &= ~( 
                        keys[SDL_SCANCODE_LSHIFT]*0x01 +
                        keys[SDL_SCANCODE_Z]*0x02 +
                        keys[SDL_SCANCODE_X]*0x04 +
                        keys[SDL_SCANCODE_C]*0x08 +
                        keys[SDL_SCANCODE_V]*0x10 );
        }
        if (!(h_addr & ~0xfd))
        {
            result &= ~( 
                        keys[SDL_SCANCODE_A]*0x01 +
                        keys[SDL_SCANCODE_S]*0x02 +
                        keys[SDL_SCANCODE_D]*0x04 +
                        keys[SDL_SCANCODE_F]*0x08 +
                        keys[SDL_SCANCODE_G]*0x10 );
        }
        if (!(h_addr & ~0xfb))
        {
            result &= ~( 
                        keys[SDL_SCANCODE_Q]*0x01 +
                        keys[SDL_SCANCODE_W]*0x02 +
                        keys[SDL_SCANCODE_E]*0x04 +
                        keys[SDL_SCANCODE_R]*0x08 +
                        keys[SDL_SCANCODE_T]*0x10 );
        }
        if (!(h_addr & ~0xf7))
        {
            result &= ~( 
                        keys[SDL_SCANCODE_1]*0x01 +
                        keys[SDL_SCANCODE_2]*0x02 +
                        keys[SDL_SCANCODE_3]*0x04 +
                        keys[SDL_SCANCODE_4]*0x08 +
                        keys[SDL_SCANCODE_5]*0x10 );
        }
        if (!(h_addr & ~0xef))
        {
            result &= ~( 
                        keys[SDL_SCANCODE_0]*0x01 +
                        keys[SDL_SCANCODE_9]*0x02 +
                        keys[SDL_SCANCODE_8]*0x04 +
                        keys[SDL_SCANCODE_7]*0x08 +
                        keys[SDL_SCANCODE_6]*0x10 );
        }
        if (!(h_addr & ~0xdf))
        {
            result &= ~( 
                        keys[SDL_SCANCODE_P]*0x01 +
                        keys[SDL_SCANCODE_O]*0x02 +
                        keys[SDL_SCANCODE_I]*0x04 +
                        keys[SDL_SCANCODE_U]*0x08 +
                        keys[SDL_SCANCODE_Y]*0x10 );
        }
        if (!(h_addr & ~0xbf))
        {
            result &= ~( 
                        keys[SDL_SCANCODE_RETURN]*0x01 +
                        keys[SDL_SCANCODE_L]*0x02 +
                        keys[SDL_SCANCODE_K]*0x04 +
                        keys[SDL_SCANCODE_J]*0x08 +
                        keys[SDL_SCANCODE_H]*0x10 );
        }
        if (!(h_addr & ~0x7f))
        {
            result &= ~( 
                        keys[SDL_SCANCODE_SPACE]*0x01 +
                        keys[SDL_SCANCODE_RSHIFT]*0x02 +
                        keys[SDL_SCANCODE_M]*0x04 +
                        keys[SDL_SCANCODE_N]*0x08 +
                        keys[SDL_SCANCODE_B]*0x10 );
        }
        return result;
    }

    void port_out(int port, int val)
    {
        border_color = val & 0x7;
        mic = (val>>3)&0x1;
        ear = (val>>4)&0x1;
        //printf("EAR:%i MIC:%i\n", ear, mic);
    }

    uint8_t get_border_color() { return border_color; }
    uint8_t get_ear() { return ear; }




    SDL_AudioDeviceID sdlAudioDevice;
    uint8_t sound_buffer[1024];
    uint16_t sound_pos;

    void audioCallback(void * userdata, uint8_t * stream, int len)
    {
        const uint16_t top = sound_pos < len ? sound_pos : len;
        memcpy(stream, sound_buffer, top);
        sound_pos=0;
    }

    void sound_init()
    {
        SDL_AudioSpec audioSpec{11025, AUDIO_U8, 1, 0, 220, 0, 0, &audioCallback, NULL};
        sdlAudioDevice = SDL_OpenAudioDevice(NULL, 0, &audioSpec, NULL, 0);
    }

    void sound_enable()
    {
        SDL_PauseAudioDevice(sdlAudioDevice, 0);
    }

    void sound_disable()
    {
        SDL_PauseAudioDevice(sdlAudioDevice, 1);
    }

    void sound_update()
    {
        sound_buffer[sound_pos++] = ear*128;
    }
}