+/* (c) 2021 Aaron Taylor <ataylor at subgeniuskitty dot com> */
+/* See LICENSE.txt file for copyright and license details. */
+
+// TODO:
+// - Write a brief description of the machine being simulated. Only one thread, reduced RAM, no meaningful console when running as screensaver, etc.
+
+// CLI Flags:
+// -path-to-aout-binary
+// -path-to-font-file
+// -speed
+
+// Ideas for sample programs to include:
+// - Build list of integers on the stack (DUP, IM_1, ADD).
+// - Calculate prime numbers, placing them on the stack.
+// - Lights sliding back and forth, like PDP-11 front panel with some OSes.
+
+#include "screenhack.h"
+#include "simulator.h"
+
+/* Keep this source code C89 compliant per XScreensaver's instructions. */
+
+/* -------------------------------------------------------------------------- */
+/* Data Structures */
+/* -------------------------------------------------------------------------- */
+
+struct NEDsim {
+ /* Various X resources */
+ Display * dpy;
+ Window win;
+ GC gc;
+
+ // TODO: Explain these
+ int dpy_width, dpy_height;
+
+ // TODO: Explain that this is created during init, then lights are populated/overwritten on each frame.
+ Pixmap panel;
+
+ /* Delay (in microseconds) between clock cycles in the NED CPU. */
+ size_t delay;
+
+ int cell_size;
+ int border_size;
+ int origin_x_offset, origin_y_offset;
+ int num_data_rows;
+
+ size_t color_index;
+
+ Bool suitable_display;
+
+ char * current_font;
+
+ // TODO: Explain that this contains all the actual state of the NED machine being simulated.
+ struct NEDstate * nedstate;
+};
+
+struct color_rgb {
+ // TODO: Explain why this is an unsigned short. Copy from WolframAutomata.
+ unsigned short red, green, blue;
+};
+
+struct color_scheme {
+ // TODO: Explain all this.
+ struct color_rgb
+ panel_bg,
+ panel_fg,
+ light_on,
+ light_off,
+ error_on,
+ error_off,
+ primary,
+ secondary,
+ tertiary,
+ border,
+ text;
+};
+
+//static struct color_scheme color_list[] = {
+// // TODO: Explain all this.
+// // TODO: Add other color schemes, like purple PDP-11/70.
+// // TODO: http://www.chdickman.com/pdp8/DECcolors/
+// {
+// {63479,63479,63479}, // 092-XXXX-123
+// { 5140, 2056, 5654}, // 092-XXXX-152
+// {40092,11051,15677}, // 092-XXXX-139
+// {30326,13107,12850}, // 092-XXXX-154
+// {65535,13107,12850}, // homemade
+// {30326,13107,12850}, // 092-XXXX-154
+// { 4112,12850,20046}, // 092-XXXX-145
+// {12336,29555,37008}, // 092-XXXX-151
+// {30326,24158, 6425}, // 092-XXXX-157
+// {63479,63479,63479}, // 092-XXXX-123
+// {63479,63479,63479} // 092-XXXX-123
+// }
+//};
+
+static struct color_scheme color_list[] = {
+ // TODO: Explain all this.
+ // TODO: Add other color schemes, like purple PDP-11/70.
+ // TODO: http://www.chdickman.com/pdp8/DECcolors/
+ {
+ {63479,63479,63479}, // 092-XXXX-123
+ { 5140, 2056, 5654}, // 092-XXXX-152
+ {65535,11051,15677}, // 092-XXXX-139 - edit
+ {20000,13107,12850}, // 092-XXXX-154 - edit
+ {65535,13107,12850}, // homemade
+ {20000,13107,12850}, // 092-XXXX-154 - edit
+ { 4112,12850,20046}, // 092-XXXX-145
+ {12336,29555,37008}, // 092-XXXX-151
+ {30326,24158, 6425}, // 092-XXXX-157
+ {63479,63479,63479}, // 092-XXXX-123
+ {63479,63479,63479} // 092-XXXX-123
+ }
+};
+
+/* -------------------------------------------------------------------------- */
+/* Helper Functions */
+/* -------------------------------------------------------------------------- */
+
+// TODO: Explain
+static void
+set_color(struct NEDsim * nedsim, struct color_rgb * color)
+{
+ XColor temp;
+ XWindowAttributes xgwa;
+
+ XGetWindowAttributes(nedsim->dpy, nedsim->win, &xgwa);
+
+ temp.red = color->red;
+ temp.green = color->green;
+ temp.blue = color->blue;
+
+ XAllocColor(nedsim->dpy, xgwa.colormap, &temp);
+ XSetForeground(nedsim->dpy, nedsim->gc, temp.pixel);
+}
+
+// TODO: Explain
+// TODO: Make this a lot faster.
+// Input: size in 'cells', and sets font to fill that size, minus border and padding room.
+static void
+set_font_size(struct NEDsim * nedsim, int size)
+{
+ // vvv--- for border ---vvv vvv--- for padding ---vvv
+ int desired_height_in_pixels = (size * nedsim->cell_size) - (2 * nedsim->border_size) - (8 * nedsim->border_size);
+
+ const char * font_size_prefix = "-*-helvetica-*-r-*-*-";
+ const char * font_size_suffix = "-*-*-*-*-*-*-*";
+
+ size_t buffer_size = strlen(font_size_prefix) + strlen(font_size_suffix) + 100; // '100' since nobody needs font with size in 'points' greater than 100 decimal digits long.
+ char * font_full_name = malloc(buffer_size);
+ int font_size_in_points = 2; // Start with a 2 pt font and work our way up.
+
+ while (1) {
+ // Load the font.
+ snprintf(font_full_name, buffer_size, "%s%d%s", font_size_prefix, font_size_in_points, font_size_suffix);
+ XFontStruct * font = XLoadQueryFont(nedsim->dpy, font_full_name);
+ if (!font) {
+ printf("WARNING: Unable to load font %s. Probably gonna look wonky.\n", font_full_name);
+ font = XLoadQueryFont(nedsim->dpy, "fixed");
+ break;
+ }
+ XSetFont(nedsim->dpy, nedsim->gc, font->fid);
+
+ // Get the height.
+ int direction, ascent, descent;
+ XCharStruct overall;
+ XTextExtents(font, "X", 1, &direction, &ascent, &descent, &overall);
+
+ // Compare the height.
+ int height = overall.ascent - overall.descent;
+ if (height == desired_height_in_pixels) {
+ break;
+ } else if (height > desired_height_in_pixels) {
+ font_size_in_points--;
+ snprintf(font_full_name, buffer_size, "%s%d%s", font_size_prefix, font_size_in_points, font_size_suffix);
+ XFontStruct * font = XLoadQueryFont(nedsim->dpy, font_full_name);
+ if (!font) {
+ printf("WARNING: Unable to load font %s. Probably gonna look wonky.\n", font_full_name);
+ font = XLoadQueryFont(nedsim->dpy, "fixed");
+ break;
+ }
+ XSetFont(nedsim->dpy, nedsim->gc, font->fid);
+ break;
+ } else {
+ font_size_in_points++;
+ }
+ }
+
+ free(nedsim->current_font);
+ nedsim->current_font = font_full_name;
+}
+
+// TODO: Explain
+// TODO: Explain that this returns result in pixels so we can track fractional cell usage.
+static void
+get_text_size(struct NEDsim * nedsim, const char * text, int * x_size, int * y_size)
+{
+ int direction, ascent, descent;
+ XCharStruct overall;
+ XFontStruct * font = XLoadQueryFont(nedsim->dpy, nedsim->current_font);
+ XTextExtents(font, text, strlen(text), &direction, &ascent, &descent, &overall);
+ *x_size = overall.width;
+ *y_size = overall.ascent - overall.descent;
+}
+
+// TODO: Explain
+// TODO: Note that this might leave the foreground color changed.
+// Argument coordinates are in 'cells', not pixels.
+static void
+draw_rect_area(struct NEDsim * nedsim, size_t x_origin, size_t y_origin, size_t x_size, size_t y_size,
+ Bool bord_top, Bool bord_bottom, Bool bord_left, Bool bord_right)
+{
+ x_origin *= nedsim->cell_size;
+ x_origin += nedsim->origin_x_offset;
+ y_origin *= nedsim->cell_size;
+ y_origin += nedsim->origin_y_offset;
+ x_size *= nedsim->cell_size;
+ y_size *= nedsim->cell_size;
+ XFillRectangle(nedsim->dpy, nedsim->win, nedsim->gc, x_origin, y_origin, x_size, y_size);
+
+ set_color(nedsim, &color_list[nedsim->color_index].border);
+ if (bord_top) {
+ XFillRectangle(nedsim->dpy, nedsim->win, nedsim->gc, x_origin, y_origin, x_size, nedsim->border_size);
+ }
+ if (bord_bottom) {
+ XFillRectangle(nedsim->dpy, nedsim->win, nedsim->gc, x_origin, (y_origin + y_size - nedsim->border_size), x_size, nedsim->border_size);
+ }
+ if (bord_left) {
+ XFillRectangle(nedsim->dpy, nedsim->win, nedsim->gc, x_origin, y_origin, nedsim->border_size, y_size);
+ }
+ if (bord_right) {
+ XFillRectangle(nedsim->dpy, nedsim->win, nedsim->gc, (x_origin + x_size - nedsim->border_size), y_origin, nedsim->border_size, y_size);
+ }
+}
+
+// TODO: Explain
+// Arguments are in units of 'cells', not pixels.
+// Will leave foreground color changed.
+// Draws filled circle with upper left corner at x,y.
+static void
+draw_circular_area(struct NEDsim * nedsim, size_t x, size_t y, double diameter)
+{
+ // First, convert the function argument units from 'cells' to 'pixels'
+ x *= nedsim->cell_size;
+ y *= nedsim->cell_size;
+ diameter *= nedsim->cell_size;
+
+ // Add the panel's absolute x,y offset to the requested coordinates.
+ x += nedsim->origin_x_offset;
+ y += nedsim->origin_y_offset;
+
+ // Shrink the circle to be a bit smaller than the bounding box allows. Note
+ // that the three adjustment values must sum to 1.0.
+ // For example, 0.7 + 0.15 + 0.15 = 1.0.
+ x += (0.15 * diameter);
+ y += (0.15 * diameter);
+ diameter *= 0.7;
+
+ // Because we only draw the bottom border on repeated rows (e.g. draw_wordline()),
+ // we need to offset vertically by half a border height.
+ y -= (0.5 * nedsim->border_size);
+
+ // Start angle 0 and ending angle 360*64 is one full circle in Xlib units.
+ XFillArc(nedsim->dpy, nedsim->win, nedsim->gc, x, y, diameter, diameter, 0, 360*64);
+}
+
+// TODO: Explain
+static void
+draw_panel(struct NEDsim * nedsim)
+{
+// TODO: Collect all relevant #defines somewhere.
+#define OVERALL_WIDTH_IN_CELLS 70
+#define HEADER_HEIGHT_IN_CELLS 14
+#define FOOTER_HEIGHT_IN_CELLS 2
+
+ // Draw background color over entire window.
+ set_color(nedsim, &color_list[nedsim->color_index].panel_bg);
+ XFillRectangle(nedsim->dpy, nedsim->win, nedsim->gc, 0, 0, nedsim->dpy_width, nedsim->dpy_height);
+
+ // Draw NED panel in foreground color.
+ set_color(nedsim, &color_list[nedsim->color_index].panel_fg);
+ XFillRectangle(nedsim->dpy, nedsim->win, nedsim->gc,
+ nedsim->origin_x_offset,
+ nedsim->origin_y_offset,
+ nedsim->cell_size * OVERALL_WIDTH_IN_CELLS,
+ nedsim->cell_size * (HEADER_HEIGHT_IN_CELLS + nedsim->num_data_rows + FOOTER_HEIGHT_IN_CELLS)
+ );
+}
+
+// TODO: Explain
+static void
+draw_logo(struct NEDsim * nedsim)
+{
+#define LOGO_X_OFFSET 2
+#define LOGO_Y_OFFSET 2
+#define LOGO_WIDTH 20
+#define LOGO_NAME_HEIGHT 6
+#define LOGO_WEBSITE_HEIGHT 2
+
+ // First draw the two colored boxes that comprise the logo area.
+ set_color(nedsim, &color_list[nedsim->color_index].primary);
+ draw_rect_area(nedsim, LOGO_X_OFFSET, LOGO_Y_OFFSET, LOGO_WIDTH, LOGO_NAME_HEIGHT, True, True, False, False);
+ set_color(nedsim, &color_list[nedsim->color_index].tertiary);
+ draw_rect_area(nedsim, LOGO_X_OFFSET, LOGO_Y_OFFSET+LOGO_NAME_HEIGHT, LOGO_WIDTH, LOGO_WEBSITE_HEIGHT, False, True, False, False);
+
+ // Now draw the 'NED' text in the top box.
+ set_color(nedsim, &color_list[nedsim->color_index].text);
+ set_font_size(nedsim, LOGO_NAME_HEIGHT);
+ int text_x_size, text_y_size;
+ get_text_size(nedsim, "NED", &text_x_size, &text_y_size);
+ int local_x_offset = ((LOGO_WIDTH * nedsim->cell_size) - text_x_size) / 2;
+ int local_y_offset = ((LOGO_NAME_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, (LOGO_X_OFFSET * nedsim->cell_size + nedsim->origin_x_offset + local_x_offset),
+ ((LOGO_Y_OFFSET+LOGO_NAME_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), "NED", 3);
+
+ // And draw the 'subgeniuskitty.com' text in the bottom box.
+ set_font_size(nedsim, LOGO_WEBSITE_HEIGHT);
+ get_text_size(nedsim, "subgeniuskitty.com", &text_x_size, &text_y_size);
+ local_x_offset = ((LOGO_WIDTH * nedsim->cell_size) - text_x_size) / 2;
+ local_y_offset = ((LOGO_WEBSITE_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, (LOGO_X_OFFSET * nedsim->cell_size + nedsim->origin_x_offset + local_x_offset),
+ ((LOGO_Y_OFFSET+LOGO_NAME_HEIGHT+LOGO_WEBSITE_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), "subgeniuskitty.com", 18);
+}
+
+// TODO: Explain
+static void
+draw_halt(struct NEDsim * nedsim)
+{
+#define HALT_X_OFFSET 26
+#define HALT_Y_OFFSET 2
+#define HALT_WIDTH 6
+#define HALT_LIGHT_HEIGHT 6
+#define HALT_LABEL_HEIGHT 2
+
+ // First draw the two colored boxes that comprise the halt area.
+ set_color(nedsim, &color_list[nedsim->color_index].tertiary);
+ draw_rect_area(nedsim, HALT_X_OFFSET, HALT_Y_OFFSET, HALT_WIDTH, HALT_LIGHT_HEIGHT, True, True, False, False);
+ set_color(nedsim, &color_list[nedsim->color_index].secondary);
+ draw_rect_area(nedsim, HALT_X_OFFSET, HALT_Y_OFFSET+HALT_LIGHT_HEIGHT, HALT_WIDTH, HALT_LABEL_HEIGHT, False, True, False, False);
+
+ // And finally, draw the label.
+ set_color(nedsim, &color_list[nedsim->color_index].text);
+ int text_x_size, text_y_size;
+ get_text_size(nedsim, "HALT", &text_x_size, &text_y_size);
+ int local_x_offset = ((HALT_WIDTH * nedsim->cell_size) - text_x_size) / 2;
+ int local_y_offset = ((HALT_LABEL_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, (HALT_X_OFFSET * nedsim->cell_size + nedsim->origin_x_offset + local_x_offset),
+ ((HALT_Y_OFFSET+HALT_LIGHT_HEIGHT+HALT_LABEL_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), "HALT", 4);
+}
+
+// TODO: Explain
+static void
+draw_wordline_lights(struct NEDsim * nedsim, uint32_t word, int x, int y)
+{
+#define WORDLINE_BITS_PER_STRIPE 4
+#define WORDLINE_WIDTH 32
+#define WORDLINE_HEIGHT 1
+
+ for (int i = 0; i < WORDLINE_WIDTH; i++) {
+ if (word & (1<<(WORDLINE_WIDTH-1-i))) {
+ set_color(nedsim, &color_list[nedsim->color_index].light_on);
+ } else {
+ set_color(nedsim, &color_list[nedsim->color_index].light_off);
+ }
+ draw_circular_area(nedsim, x+i, y, WORDLINE_HEIGHT);
+ }
+}
+
+// TODO: Explain
+static void
+draw_wordline(struct NEDsim * nedsim, int x, int y)
+{
+ // First, draw a solid box in the primary color over the entire wordline area.
+ set_color(nedsim, &color_list[nedsim->color_index].primary);
+ draw_rect_area(nedsim, x, y, WORDLINE_WIDTH, WORDLINE_HEIGHT, False, True, False, False);
+
+ // Now, draw stripes in the secondary color.
+ int i;
+ for (i = 0; i < (WORDLINE_WIDTH/(2*WORDLINE_BITS_PER_STRIPE)); i++) {
+ set_color(nedsim, &color_list[nedsim->color_index].secondary);
+ draw_rect_area(nedsim, (x+(i*(WORDLINE_WIDTH/WORDLINE_BITS_PER_STRIPE))), y,
+ WORDLINE_BITS_PER_STRIPE, WORDLINE_HEIGHT, False, True, False, False);
+ }
+
+ // Finally, draw the lights.
+ draw_wordline_lights(nedsim, 0, x, y);
+}
+
+// TODO: Explain
+static void
+draw_pc(struct NEDsim * nedsim)
+{
+// TODO: Note that all #defines use units of 'cells', not 'pixels', etc.
+#define PC_X_OFFSET 36
+#define PC_Y_OFFSET 7
+#define PC_WIDTH 32
+#define PC_LABEL_HEIGHT 2
+#define PC_LIGHT_HEIGHT 1
+
+ // First draw the two colored boxes that comprise the PC area.
+ set_color(nedsim, &color_list[nedsim->color_index].tertiary);
+ draw_rect_area(nedsim, PC_X_OFFSET, PC_Y_OFFSET, PC_WIDTH, PC_LABEL_HEIGHT, True, True, False, False);
+ draw_wordline(nedsim, PC_X_OFFSET, PC_Y_OFFSET+PC_LABEL_HEIGHT);
+
+ // Now draw the label text "PC".
+ set_color(nedsim, &color_list[nedsim->color_index].text);
+ int text_x_size, text_y_size;
+ get_text_size(nedsim, "PC", &text_x_size, &text_y_size);
+ int local_x_offset = ((PC_WIDTH * nedsim->cell_size) - text_x_size) / 2;
+ int local_y_offset = ((PC_LABEL_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, (PC_X_OFFSET * nedsim->cell_size + nedsim->origin_x_offset + local_x_offset),
+ ((PC_Y_OFFSET+PC_LABEL_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), "PC", 2);
+}
+
+// TODO: Explain
+static void
+draw_sc(struct NEDsim * nedsim)
+{
+#define SC_X_OFFSET 42
+#define SC_Y_OFFSET 2
+#define SC_WIDTH 5
+#define SC_LABEL_HEIGHT 2
+#define SC_LIGHT_HEIGHT 1
+
+ // First draw the two colored boxes that comprise the SC area.
+ set_color(nedsim, &color_list[nedsim->color_index].secondary);
+ draw_rect_area(nedsim, SC_X_OFFSET, SC_Y_OFFSET, SC_WIDTH, SC_LABEL_HEIGHT, True, True, False, False);
+ set_color(nedsim, &color_list[nedsim->color_index].tertiary);
+ draw_rect_area(nedsim, SC_X_OFFSET, SC_Y_OFFSET+SC_LABEL_HEIGHT, SC_WIDTH, SC_LIGHT_HEIGHT, False, True, False, False);
+
+ // Now draw the label text "SC".
+ set_color(nedsim, &color_list[nedsim->color_index].text);
+ int text_x_size, text_y_size;
+ get_text_size(nedsim, "SC", &text_x_size, &text_y_size);
+ int local_x_offset = ((SC_WIDTH * nedsim->cell_size) - text_x_size) / 2;
+ int local_y_offset = ((SC_LABEL_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, (SC_X_OFFSET * nedsim->cell_size + nedsim->origin_x_offset + local_x_offset),
+ ((SC_Y_OFFSET+SC_LABEL_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), "SC", 2);
+}
+
+// TODO: Explain
+static void
+draw_psw(struct NEDsim * nedsim)
+{
+#define PSW_N_X_OFFSET 51
+#define PSW_Z_X_OFFSET 58
+#define PSW_Y_OFFSET 2
+#define PSW_LABEL_WIDTH 3
+#define PSW_LABEL_HEIGHT 2
+#define PSW_LIGHT_WIDTH 1
+#define PSW_LIGHT_HEIGHT 1
+
+ // First draw the four colored boxes that comprise the two PSW areas.
+ set_color(nedsim, &color_list[nedsim->color_index].secondary);
+ draw_rect_area(nedsim, PSW_N_X_OFFSET, PSW_Y_OFFSET, PSW_LABEL_WIDTH, PSW_LABEL_HEIGHT, True, True, False, False);
+ set_color(nedsim, &color_list[nedsim->color_index].secondary);
+ draw_rect_area(nedsim, PSW_Z_X_OFFSET, PSW_Y_OFFSET, PSW_LABEL_WIDTH, PSW_LABEL_HEIGHT, True, True, False, False);
+ set_color(nedsim, &color_list[nedsim->color_index].tertiary);
+ draw_rect_area(nedsim, (PSW_N_X_OFFSET + 1), PSW_Y_OFFSET+PSW_LABEL_HEIGHT, PSW_LIGHT_WIDTH, PSW_LIGHT_HEIGHT, False, True, False, False);
+ set_color(nedsim, &color_list[nedsim->color_index].tertiary);
+ draw_rect_area(nedsim, (PSW_Z_X_OFFSET + 1), PSW_Y_OFFSET+PSW_LABEL_HEIGHT, PSW_LIGHT_WIDTH, PSW_LIGHT_HEIGHT, False, True, False, False);
+
+ // Now draw the label text "N".
+ set_color(nedsim, &color_list[nedsim->color_index].text);
+ int text_x_size, text_y_size;
+ get_text_size(nedsim, "N", &text_x_size, &text_y_size);
+ int local_x_offset = ((PSW_LABEL_WIDTH * nedsim->cell_size) - text_x_size) / 2;
+ int local_y_offset = ((PSW_LABEL_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, (PSW_N_X_OFFSET * nedsim->cell_size + nedsim->origin_x_offset + local_x_offset),
+ ((PSW_Y_OFFSET+PSW_LABEL_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), "N", 1);
+
+ // Now draw the label text "Z".
+ set_color(nedsim, &color_list[nedsim->color_index].text);
+ get_text_size(nedsim, "Z", &text_x_size, &text_y_size);
+ local_x_offset = ((PSW_LABEL_WIDTH * nedsim->cell_size) - text_x_size) / 2;
+ local_y_offset = ((PSW_LABEL_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, (PSW_Z_X_OFFSET * nedsim->cell_size + nedsim->origin_x_offset + local_x_offset),
+ ((PSW_Y_OFFSET+PSW_LABEL_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), "Z", 1);
+}
+
+// TODO: Explain
+static void
+draw_stack(struct NEDsim * nedsim)
+{
+#define STACK_X_OFFSET 2
+#define STACK_Y_OFFSET 12
+#define STACK_WIDTH 32
+#define STACK_LABEL_HEIGHT 2
+#define STACK_LIGHT_HEIGHT 1
+
+ // First draw the two colored boxes that comprise the stack area.
+ set_color(nedsim, &color_list[nedsim->color_index].tertiary);
+ draw_rect_area(nedsim, STACK_X_OFFSET, STACK_Y_OFFSET, STACK_WIDTH, STACK_LABEL_HEIGHT, True, True, False, False);
+ for (int i = 0; i < nedsim->num_data_rows; i++) {
+ draw_wordline(nedsim, STACK_X_OFFSET, STACK_Y_OFFSET+STACK_LABEL_HEIGHT+i);
+ }
+
+ // Now draw the label text "Stack Size:".
+ set_color(nedsim, &color_list[nedsim->color_index].text);
+ int text_x_size, text_y_size;
+ get_text_size(nedsim, "Stack Size:", &text_x_size, &text_y_size);
+ int local_y_offset = ((STACK_LABEL_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, ((STACK_X_OFFSET + 1) * nedsim->cell_size + nedsim->origin_x_offset),
+ ((STACK_Y_OFFSET+STACK_LABEL_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), "Stack Size:", 11);
+}
+
+// TODO: Explain
+static void
+draw_heap(struct NEDsim * nedsim)
+{
+#define HEAP_X_OFFSET 36
+#define HEAP_Y_OFFSET 12
+#define HEAP_WIDTH 32
+#define HEAP_LABEL_HEIGHT 2
+#define HEAP_LIGHT_HEIGHT 1
+// TODO: What should I do about this define? I would like to be able to specify the address so I can do things like display the code itself if nothign interesting happens in RAM.
+#define HEAP_START_ADDRESS 0x20000000
+
+ // First draw the two colored boxes that comprise the heap area.
+ set_color(nedsim, &color_list[nedsim->color_index].tertiary);
+ draw_rect_area(nedsim, HEAP_X_OFFSET, HEAP_Y_OFFSET, HEAP_WIDTH, HEAP_LABEL_HEIGHT, True, True, False, False);
+ for (int i = 0; i < nedsim->num_data_rows; i++) {
+ draw_wordline(nedsim, HEAP_X_OFFSET, HEAP_Y_OFFSET+HEAP_LABEL_HEIGHT+i);
+ }
+
+ // Now draw the label text "RAM Base:".
+ set_color(nedsim, &color_list[nedsim->color_index].text);
+ int text_x_size, text_y_size;
+ get_text_size(nedsim, "RAM Base:", &text_x_size, &text_y_size);
+ int local_y_offset = ((HEAP_LABEL_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, ((HEAP_X_OFFSET + 1) * nedsim->cell_size + nedsim->origin_x_offset),
+ ((HEAP_Y_OFFSET+HEAP_LABEL_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), "RAM Base:", 9);
+
+ // Now draw the address text.
+ set_color(nedsim, &color_list[nedsim->color_index].text);
+ char address[11];
+ snprintf(address, sizeof(address), "0x%08X", HEAP_START_ADDRESS);
+ get_text_size(nedsim, address, &text_x_size, &text_y_size);
+ local_y_offset = ((HEAP_LABEL_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, ((HEAP_X_OFFSET + 1 + (HEAP_WIDTH / 2)) * nedsim->cell_size + nedsim->origin_x_offset),
+ ((HEAP_Y_OFFSET+HEAP_LABEL_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), address, strlen(address));
+}
+
+// TODO: Explain
+static void
+update_display(struct NEDsim * nedsim)
+{
+ // Draw the halt indicator.
+ if (nedsim->nedstate->halted) {
+ set_color(nedsim, &color_list[nedsim->color_index].error_on);
+ } else {
+ set_color(nedsim, &color_list[nedsim->color_index].error_off);
+ }
+ draw_circular_area(nedsim, HALT_X_OFFSET, HALT_Y_OFFSET, HALT_WIDTH);
+
+ // Draw the PSW "N" light.
+ if (nedsim->nedstate->active_thread->psw->negative) {
+ set_color(nedsim, &color_list[nedsim->color_index].light_on);
+ } else {
+ set_color(nedsim, &color_list[nedsim->color_index].light_off);
+ }
+ draw_circular_area(nedsim, PSW_N_X_OFFSET+1, PSW_Y_OFFSET+PSW_LABEL_HEIGHT, PSW_LIGHT_HEIGHT);
+
+ // Draw the PSW "Z" light.
+ if (nedsim->nedstate->active_thread->psw->zero) {
+ set_color(nedsim, &color_list[nedsim->color_index].light_on);
+ } else {
+ set_color(nedsim, &color_list[nedsim->color_index].light_off);
+ }
+ draw_circular_area(nedsim, PSW_Z_X_OFFSET+1, PSW_Y_OFFSET+PSW_LABEL_HEIGHT, PSW_LIGHT_HEIGHT);
+
+
+ // Draw the SC.
+ int i;
+ for (i = 0; i < SC_WIDTH; i++) {
+ if ((SC_WIDTH-1-i) == nedsim->nedstate->active_thread->sc) {
+ set_color(nedsim, &color_list[nedsim->color_index].light_on);
+ } else {
+ set_color(nedsim, &color_list[nedsim->color_index].light_off);
+ }
+ draw_circular_area(nedsim, SC_X_OFFSET+i, SC_Y_OFFSET+SC_LABEL_HEIGHT, SC_LIGHT_HEIGHT);
+ }
+
+ // Draw the PC.
+ draw_wordline_lights(nedsim, nedsim->nedstate->active_thread->pc, PC_X_OFFSET, PC_Y_OFFSET+PC_LABEL_HEIGHT);
+
+ // Draw the stack lights.
+ int64_t top_of_stack = ((int64_t)nedsim->nedstate->active_thread->sp) - 1;
+ for (i = 0; i < nedsim->num_data_rows; i++) {
+ if ((top_of_stack-i) >= 0) {
+ draw_wordline_lights(nedsim, nedsim->nedstate->active_thread->stack[top_of_stack-i], STACK_X_OFFSET, STACK_Y_OFFSET+STACK_LABEL_HEIGHT+i);
+ } else {
+ draw_wordline_lights(nedsim, 0, STACK_X_OFFSET, STACK_Y_OFFSET+STACK_LABEL_HEIGHT+i);
+ }
+ }
+
+ // Draw the stack size in text.
+ set_color(nedsim, &color_list[nedsim->color_index].tertiary);
+ draw_rect_area(nedsim, STACK_X_OFFSET+(STACK_WIDTH/2), STACK_Y_OFFSET, STACK_WIDTH/2, STACK_LABEL_HEIGHT, True, True, False, False);
+ set_color(nedsim, &color_list[nedsim->color_index].text);
+ char stack_size[11];
+ snprintf(stack_size, sizeof(stack_size), "0x%08X", nedsim->nedstate->active_thread->sp);
+ int text_x_size, text_y_size;
+ get_text_size(nedsim, stack_size, &text_x_size, &text_y_size);
+ int local_y_offset = ((STACK_LABEL_HEIGHT * nedsim->cell_size) - text_y_size) / 2;
+ XDrawString(nedsim->dpy, nedsim->win, nedsim->gc, ((STACK_X_OFFSET + 1 + (STACK_WIDTH / 2)) * nedsim->cell_size + nedsim->origin_x_offset),
+ ((STACK_Y_OFFSET+STACK_LABEL_HEIGHT) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), stack_size, strlen(stack_size));
+
+ // Draw the heap lights.
+ for (i = 0; i < nedsim->num_data_rows; i++) {
+ draw_wordline_lights(nedsim, ram_r_word(nedsim->nedstate, HEAP_START_ADDRESS+(i*BPW)), HEAP_X_OFFSET, HEAP_Y_OFFSET+HEAP_LABEL_HEIGHT+i);
+ }
+}
+
+/* -------------------------------------------------------------------------- */
+/* Screenhack API Functions */
+/* -------------------------------------------------------------------------- */
+
+static Bool
+NEDsim_event(Display * dpy, Window win, void * closure, XEvent * event)
+{
+ return False;
+}
+
+static void
+NEDsim_free(Display * dpy, Window win, void * closure)
+{
+ // TODO: Replace all this with proper code to free everything.
+ struct NEDsim * nedsim = closure;
+ XFreeGC(nedsim->dpy, nedsim->gc);
+ free(nedsim);
+}
+
+static void *
+NEDsim_init(Display * dpy, Window win)
+{
+ struct NEDsim * nedsim;
+ XGCValues gcv;
+ XWindowAttributes xgwa;
+
+ nedsim = calloc(1, sizeof(*nedsim));
+ if (!nedsim) {
+ fprintf(stderr, "ERROR: Failed to calloc() for NEDsim struct in NEDsim_init().\n");
+ exit(EXIT_FAILURE);
+ }
+
+ nedsim->dpy = dpy;
+ nedsim->win = win;
+
+ XGetWindowAttributes(nedsim->dpy, nedsim->win, &xgwa);
+ nedsim->dpy_width = xgwa.width;
+ nedsim->dpy_height = xgwa.height;
+
+ // TODO: Explain that this is the delay between each clock cycle of the simulated NED CPU.
+ nedsim->delay = get_integer_resource(nedsim->dpy, "delay", "Integer");
+ nedsim->delay *= 1000; /* Turn milliseconds into microseconds. */
+
+ // TODO: Read in the a.out file. This should be done in the simulator's init function call?
+ nedsim->nedstate = init_simulator();
+
+ nedsim->gc = XCreateGC(nedsim->dpy, nedsim->win, GCForeground, &gcv);
+
+ // TODO: Do this properly.
+ nedsim->color_index = 0;
+
+// TODO: Save the GIMP reference diagram somewhere, along with notes about the size/spacing, and that each cell is 10 pixels across in the reference image.
+
+ nedsim->cell_size = nedsim->dpy_width / OVERALL_WIDTH_IN_CELLS ; // make panel as wide as it can be while keeping every cell an integer pixel size.
+ // TODO: What is my minimum cell_size? Below that, I should simply paint the window red and print an error in the console. Perform that check here, right after setting cell_size.
+ // For now, we'll just make it 10 pixels?
+ if (nedsim->cell_size < 10) {
+ nedsim->suitable_display = False;
+ return nedsim;
+ }
+ nedsim->origin_x_offset = (nedsim->dpy_width - (nedsim->cell_size * OVERALL_WIDTH_IN_CELLS)) / 2; // center panel horizontally
+
+ // Determine how many rows for the stack and heap displays. Make it the largest power of two that fits on the display.
+ int available_space_for_data_rows = nedsim->dpy_height - (nedsim->cell_size * (HEADER_HEIGHT_IN_CELLS + FOOTER_HEIGHT_IN_CELLS));
+ for (int i = 0; ; i++) {
+ if ((nedsim->cell_size * (1 << i)) > available_space_for_data_rows) {
+ nedsim->num_data_rows = (1 << --i);
+ break;
+ }
+ }
+ if (nedsim->num_data_rows < 4) {
+ nedsim->suitable_display = False;
+ return nedsim;
+ }
+ nedsim->origin_y_offset = (nedsim->dpy_height - (nedsim->cell_size * (HEADER_HEIGHT_IN_CELLS + nedsim->num_data_rows + FOOTER_HEIGHT_IN_CELLS))) / 2; // center panel vertically
+
+ // Scale border relative to cell_size in a 1:10 relationship.
+ nedsim->border_size = nedsim->cell_size / 10;
+
+ draw_panel(nedsim);
+ draw_logo(nedsim);
+ draw_halt(nedsim);
+ draw_pc(nedsim);
+ draw_sc(nedsim);
+ draw_psw(nedsim);
+ draw_stack(nedsim);
+ draw_heap(nedsim);
+
+ nedsim->suitable_display = True;
+
+ return nedsim;
+}
+
+static unsigned long
+NEDsim_draw(Display * dpy, Window win, void * closure)
+{
+ struct NEDsim * nedsim = closure;
+
+ if (nedsim->suitable_display) {
+ nedsim->nedstate = run_simulator(nedsim->nedstate);
+ update_display(nedsim);
+ } else {
+ set_color(nedsim, &color_list[nedsim->color_index].error_on);
+ XFillRectangle(nedsim->dpy, nedsim->win, nedsim->gc, 0, 0, nedsim->dpy_width, nedsim->dpy_height);
+ }
+
+ return nedsim->delay;
+}
+
+static void
+NEDsim_reshape(Display * dpy, Window win, void * closure, unsigned int w, unsigned int h)
+{
+ struct NEDsim * nedsim = closure;
+ XWindowAttributes xgwa;
+ XGetWindowAttributes(nedsim->dpy, nedsim->win, &xgwa);
+ /* Only restart the simulation if the window changed size. */
+ if (nedsim->dpy_width != xgwa.width || nedsim->dpy_height != xgwa.height) {
+ NEDsim_free(dpy, win, closure);
+ closure = NEDsim_init(dpy, win);
+ }
+}
+
+static const char * NEDsim_defaults[] = {
+ "*delay: 250",
+ 0
+};
+
+static XrmOptionDescRec NEDsim_options[] = {
+ { "-delay", ".delay", XrmoptionSepArg, 0 },
+ { 0, 0, 0, 0 }
+};
+
+XSCREENSAVER_MODULE ("Blinken-lights simulator for NED1 CPU architecture.", NEDsim)
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