screen-maps.c

/*
  Program for generating simple screen map diagrams for the MEGA65 documentation.

  It is designed to produce maps showing screen addresses in various modes, as well
  as the memory layout corresponding to various actual displays.

  It's basically an ad-hoc tool being developed to save me having to spend hours
  making SVG diagrams with the same content.
*/

#include <stdio.h>
#include <hpdf.h>

int logical_columns = 40;
int columns = 40;
int rows = 25;
int screen_address = 0x400;
int show_cell_numbers = 1;
int show_addrs = 0;
int show_chars = 0;
int sixteenbit_mode = 0;

HPDF_Doc pdf;
HPDF_Page page_1;

void reset_settings(void)
{
  logical_columns = 40;
  columns = 40;
  rows = 25;
  screen_address = 0x400;
  show_cell_numbers = 0;
  show_addrs = 0;
  show_chars = 0;
  sixteenbit_mode = 0;
}

void error_handler(HPDF_STATUS error_no, HPDF_STATUS detail_no, void* user_data)
{
  printf("ERROR: error_no=%04X, detail_no=%d\n", (unsigned int)error_no, (int)detail_no);
  exit(-1);
}

void setup_pdf(void)
{

  pdf = HPDF_New(error_handler, NULL);
  if (!pdf) {
    printf("ERROR: cannot create pdf object.\n");
    exit(-3);
  }

  /* set compression mode */
  HPDF_SetCompressionMode(pdf, HPDF_COMP_ALL);

  page_1 = HPDF_AddPage(pdf);

  HPDF_Page_SetWidth(page_1, 660);
  HPDF_Page_SetHeight(page_1, 420);

  for (int x = 0; x <= columns; x++) {
    HPDF_Page_MoveTo(page_1, 10 + (x * 640 / columns), 10 + 0);
    HPDF_Page_LineTo(page_1, 10 + (x * 640 / columns), 10 + 400);
    HPDF_Page_Stroke(page_1);
  }

  for (int y = 0; y <= rows; y++) {
    HPDF_Page_MoveTo(page_1, 10 + 0, 10 + (y * 400 / rows));
    HPDF_Page_LineTo(page_1, 10 + 640, 10 + (y * 400 / rows));
    HPDF_Page_Stroke(page_1);
  }

  //  const char *font_name = HPDF_LoadTTFontFromFile (pdf, "./fonts/mega40-Regular.ttf", HPDF_TRUE);
  HPDF_Font font = HPDF_GetFont(pdf, "Helvetica", "CP1250");

  if (show_addrs) {
    // Smaller print for addresses
    HPDF_Page_SetFontAndSize(page_1, font, 640 / columns / 2 * 0.75);
  }
  else {
    HPDF_Page_SetFontAndSize(page_1, font, 640 / columns / 2);
  }

  HPDF_Page_BeginText(page_1);
}

void finalise_pdf(char* pdfname)
{
  HPDF_Page_EndText(page_1);

  HPDF_SaveToFile(pdf, pdfname);

  HPDF_Free(pdf);
}

void draw_screen_layout(void)
{
  for (int y = 0; y < rows; y++) {
    for (int x = 0; x < columns; x++) {
      char string[80];

      string[0] = 0;
      if (show_cell_numbers)
        snprintf(string, 80, "%d", (y * columns + x) * (1 + sixteenbit_mode));
      if (show_addrs)
        snprintf(string, 80, "$%x", screen_address + y * logical_columns + x * (1 + sixteenbit_mode));
      HPDF_Page_TextOut(page_1, 10 + 1 + (x * 640 / columns), 400 - (y * 400 / rows), string);
    }
  }
}

int main(int argc, char** argv)
{

  // Draw normal 40x25 grid with cell numbers
  reset_settings();
  show_cell_numbers = 1;
  setup_pdf();
  draw_screen_layout();
  finalise_pdf("images/illustrations/screen-40x25-cell-numbers.pdf");

  // Draw normal 40x25 grid with addresses
  reset_settings();
  show_addrs = 1;
  setup_pdf();
  draw_screen_layout();
  finalise_pdf("images/illustrations/screen-40x25-addresses.pdf");

  // Draw normal 40x25 grid with addresses, 16-bit char mode with 40 byte logical stepping
  reset_settings();
  show_addrs = 1;
  sixteenbit_mode = 1;
  setup_pdf();
  draw_screen_layout();
  finalise_pdf("images/illustrations/screen-40x25-addresses16.pdf");

  // Draw normal 40x25 grid with addresses, 16-bit char mode with 80 byte logical stepping
  reset_settings();
  show_addrs = 1;
  sixteenbit_mode = 1;
  logical_columns = 80;
  setup_pdf();
  draw_screen_layout();
  finalise_pdf("images/illustrations/screen-40x25-addresses16-80.pdf");
}