File content as of revision 13:9cf720873bf6:

#include "mbed.h"
#include <math.h>
#include "main.h"
#include "raster.h"

#define TEXT_LEVEL 5

#define TX 24  // number of characters in X
#define TY 18  // number of characters in Y

#define CHECK_BIT(var,pos) ((var) & (1<<(pos)))
#define MIN(a,b) (((a)<(b))?(a):(b))
#define MAX(a,b) (((a)>(b))?(a):(b))

#define N_COLOR 16

// DAC stuff
#define DAC_SYNC 2

uint8_t char_col = 0;  // current column counter
uint8_t char_row = 0;  // current row counter
uint8_t text_buffer_counter = 0; // current index in text buffer counter
char most_recent_char = '0';

uint8_t line_intensity = 0;
int8_t line_dir = 1;

char text_buffer[TX*TY]; // input text buffer for lisp

AnalogIn joy1(A1);
AnalogIn joy2(A0);

uint8_t want_gfx = 0;
uint8_t vsync = 0;

Serial pc(USBTX, USBRX);

#include "vincent_data.h"

DigitalOut sout(D8); //sync PA_9
DigitalOut vout(D7); //video PA_8

DigitalOut dac0(PA_4);
DigitalOut dac1(PA_5);
DigitalOut dac2(PA_6);
DigitalOut dac3(PA_7);

// trigger horizontal line draw
Ticker t;

uint8_t draw_line_inv = 0;

uint8_t bl_line_s[H_RES]; //blank line sync buffer
uint8_t bl_line_v[H_RES]; //blank line video buffer
uint8_t vb_line_s[H_RES]; //vertical sync, sync buffer
uint8_t vb_line_v[H_RES]; //vertical sync, video buffer
uint8_t im_line_s[H_RES]; //image sync buffer
uint8_t im_line_va_1[H_RES*V_RES];
uint8_t* im_line_va; // active image buff

uint16_t l=0; //current line of scan

// positive or negative?
int16_t sign(int16_t a)
{
    if(a > 0) return 1;
    if(a < 0) return -1;
    return 0;
}

// clear the text buffer
void clr_text_buff()
{
    text_buffer_counter = 0;
    for(int i = 0; i < TX*TY; i++)
        text_buffer[i] = 0;
}

// clear the screen and the text buffer
void clr()
{
    for(int i = 0; i < H_RES; i++)
        for(int j = 0; j < V_RES; j++)
            im_line_va[i+j*H_RES] = 0;
            
    clr_text_buff();
    
}

// initialize video buffers
void init_buffers()
{
    clr(); // zero buffers
    for(int i = 0; i < H_RES; i++)
    {
        im_line_s[i] = DAC_SYNC;   
        bl_line_s[i] = DAC_SYNC;
        bl_line_v[i] = 0;
        vb_line_s[i] = 0;
        vb_line_v[i] = 0;
    }    
    im_line_s[0] = 0;
    im_line_s[1] = 0;
    im_line_s[2] = 0;
    im_line_s[3] = 0;
    
    for(int i = 0; i < 15; i++) im_line_s[i] = 0;
    
    bl_line_s[0] = 0;
    vb_line_s[0] = DAC_SYNC;
    bl_line_s[1] = 0;
    vb_line_s[1] = DAC_SYNC;
    
    bl_line_s[3] = 0;
    vb_line_s[3] = DAC_SYNC;
    bl_line_s[2] = 0;
    vb_line_s[2] = DAC_SYNC;
}

// video interrupt
void isr()
{
    uint8_t nop = 0; //use nops or use wait_us
    uint8_t* sptr; //pointer to sync buffer for line
    uint8_t* vptr; //pointer to video buffer for line
    if(l < V_RES){ vptr = im_line_va + ((l)*H_RES); sptr = im_line_s; nop = 1; vsync = 0;} //pick line buffers
    else if(l < 254){ vptr = bl_line_v; sptr = bl_line_s; nop = 0;  }
    else{ vptr = vb_line_v; sptr = vb_line_s; nop = 1; }
    uint16_t lmax = nop?H_RES:12; //number of columns
    for(uint16_t i = 0; i < lmax; i++) //loop over each column
    {
        nop = 1;
        GPIOA->ODR = (vptr[i] + sptr[i]) << 4;

        if(nop) //nop delay
        {
            asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");asm("nop");//asm("nop");asm("nop");asm("nop");asm("nop");
        }
        else {wait_us(1); if(i > 2) i+=1;} //wait delay 
    }
    //move to next line
    l++;
    if(l == V_RES) vsync = 1;
    if(l > 255) l = 0;
}

// draw vertical line
void draw_vert(int16_t y0, int16_t y1, int16_t x0)
{
    for(int16_t i = y0; i < y1; i++)
        im_line_va[H_RES*i + x0] = line_intensity;
}

// draw horizonal line
void draw_horiz(int16_t x0, int16_t x1, int16_t y0)
{
    for(int16_t i = x0; i < x1; i++)
        im_line_va[H_RES*y0 + i] = line_intensity;
}

// draw line between points
void draw_line(int16_t x0, int16_t y0, int16_t x1, int16_t y1)
{
    if(x0 > x1){ x0 = x0 ^ x1; x1 = x1^x0; x0 = x0^x1;y0 = y0 ^ y1; y1 = y1^y0; y0 = y0^y1; }
    if(x0 == x1){draw_vert(y0,y1,x0);}
    if(y0 == y1){draw_horiz(x0,x1,y0);}
    int16_t dx = x1 - x0;
    int16_t dy = y1 - y0;
    float derr = fabs((float)(dy)/(float)(dx));
    float err = 0.f;
    int16_t y = y0;
    for(int16_t x = x0; x < x1; x++)
    {
        //plotxy
        im_line_va[H_RES*y + x] = (!draw_line_inv)?line_intensity:0;
        err += derr;
        while(err >= 0.5f)
        {
            y +=  sign(dy);
            im_line_va[H_RES*y + x] = (!draw_line_inv)?line_intensity:0;
            err -= 1.f;
        }   
    }
}

// draw letter
void draw_vincent(uint16_t x0, uint16_t y0, uint8_t c)
{
    if(c == 40) c = 41;
    else if(c == 41) c = 40;
    char* letter = vincent_data[c];
    for(uint16_t xp = 0; xp < 8; xp++)
    {
        for(uint16_t yp = 0; yp < 8; yp++)
        {
            im_line_va[H_RES*(yp+y0) + xp + x0] = CHECK_BIT(letter[yp],8-xp)?TEXT_LEVEL:0;
        }
    }
}

// go to new line
void new_line()
{
    char_col = 0;
    char_row++;
    if(char_row >= TY)
    {
        char_row = 0;
    }
}

// draw string
void draw_vincent_string(char* str)
{
    for(int i = 0; i < strlen(str); i++)
    {
        if(str[i] == 0) return;
        char_col++; 
    if(char_col >= TX)
    {
        char_col = 0;
        char_row++;
    }
    if(char_row >= TY)
    {
        char_row = 0;
    }
    
    draw_vincent(X0 +2 + 8*char_col, Y0 + 14 + 8*char_row, 
        str[i]);
    }
}

void set_status_string(char* str)
{
    uint8_t char_col_backup = char_col;
    uint8_t char_row_backup = char_row;
    char_col = 0;
    char_row = TY - 1;
    
    draw_vincent_string(str);
    
    char_col = char_col_backup;
    char_row = char_row_backup;
}

//screen goes from -.5 to .5 on both axes
void draw_gfx_line(float x0, float y0, float x1, float y1)
{
    float x_width = (XL);
    float y_height = (YL);
    
    // want to rescale to 0 to 1
    x0 += 0.5f;
    y0 += 0.5f;
    
    x1 += 0.5f;
    y1 += 0.5f;
    //printf("x0: %.3f, y0: %.3f\r\n",x0,y0);
    int xx = x0 * x_width + X0;
    if(xx > (X0 + XL)) xx = (X0 + XL);
    if(xx < X0) xx = X0;
    int yy = y0 * y_height + Y0;
    if(yy > (Y0 + YL)) yy = (Y0 + YL);
    if(yy < Y0) yy = Y0;   
    
    int xx1 = x1 * x_width + X0;
    if(xx1 > (X0 + XL)) xx1 = (X0 + XL);
    if(xx1 < X0) xx1 = X0;
    int yy1 = y1 * y_height + Y0;
    if(yy1 > (Y0 + YL)) yy1 = (Y0 + YL);
    if(yy1 < Y0) yy1 = Y0;   
    
    draw_line(xx,yy,xx1,yy1);
}

int main()
{
    im_line_va = im_line_va_1;
    //init serial
    pc.baud(115200);
    pc.printf("derp!\r\n");
 
    //init buffers
    init_buffers();
    //init timer
    t.attach_us(&isr,64);
    //clear zbuffer
    clear_zbuf();
        
    wait_us(200000);
    
    add_quad(-32, -32, -32, 32, -32, -32, 32, -32, 32, -32, -32, 32, 4);
    add_quad(32, -32, -32, 32, -32, 32, 32, 32, 32, 32, 32, -32, 2);
    add_quad(32, 32, -32, 32, 32, 32, -32, 32, 32, -32, 32, -32, 7);
    add_quad(-32, 32, -32, -32, 32, 32, -32, -32, 32, -32, -32, -32, 6);
    add_quad(-32, 32, -32, 32, 32, -32, 32, -32, -32, -32, -32, -32, 3);
    add_quad(-32, 32, 32, 32, 32, 32, 32, -32, 32, -32, -32, 32, 5);
    theta = 0.0f; phi = 0.0f; cx = 0; cy = 0; cz = 100;

    int num_iters;
    for(;;) 
    {
        if(!vsync) continue;
        
        clr();
        float j2 = joy1.read() - .5f;;
        float j1 = joy2.read() - .5f;
        
        num_iters++;
    
        if( (num_iters % 5) == 0)
        {
            if(line_dir == 1)
            {
                line_intensity++;
                if(line_intensity >= 8)
                    line_dir = -1;
            }
            else
            {
                line_intensity--;
                if(line_intensity == 0) line_dir = 1;
            }   
        }
        
        theta += j2 / 5.0f;
        phi += j1 / 5.0f;
        clear_zbuf();
        render_quads();
                
        draw_line(X0, Y0, X0 + XL, Y0);
        draw_line(X0+XL,Y0,X0+XL,Y0+YL);
        draw_line(X0, Y0+YL, X0 +XL, Y0+YL);
        draw_line(X0,Y0,X0,Y0+YL);
        most_recent_char = '0';

        char joy_string[20];
        sprintf(joy_string,"1: %.2f 2: %.2f",joy1.read(),joy2.read());
        set_status_string(joy_string);
        
        vsync = 0;            
    }
}