X-Git-Url: http://git.subgeniuskitty.com/screensavers/.git/blobdiff_plain/28edd14e63bf05e41af6c170523b929303a6c132..76081fc38a220dce90da780b67c3d61e1a257cb8:/hacks/NEDsim/NEDsim.c

diff --git a/hacks/NEDsim/NEDsim.c b/hacks/NEDsim/NEDsim.c
index e40d839..f710105 100644
--- a/hacks/NEDsim/NEDsim.c
+++ b/hacks/NEDsim/NEDsim.c
@@ -186,7 +186,7 @@ static struct color_scheme color_list[] = {
 /* Helper Functions                                                           */
 /* -------------------------------------------------------------------------- */
 
-// TODO: Explain
+// Set foreground color for the current graphics context.
 static void
 set_color(struct NEDsim * nedsim, struct color_rgb * color)
 {
@@ -203,9 +203,8 @@ set_color(struct NEDsim * nedsim, struct color_rgb * color)
     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.
+// Set font size to fill 'size' cells vertically, minus space for border and padding.
 static void
 set_font_size(struct NEDsim * nedsim, int size)
 {
@@ -259,8 +258,9 @@ set_font_size(struct NEDsim * nedsim, int size)
     nedsim->current_font = font_full_name;
 }
 
-// TODO: Explain
-// TODO: Explain that this returns result in pixels so we can track fractional cell usage.
+// Unlike most functions in this program that input/output in units of 'cells',
+// this function uses units of 'pixels' so the caller can track fractional cell
+// usage (e.g. for centering the text).
 static void
 get_text_size(struct NEDsim * nedsim, const char * text, int * x_size, int * y_size)
 {
@@ -272,13 +272,14 @@ get_text_size(struct NEDsim * nedsim, const char * text, int * x_size, int * y_s
     *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.
+// When specifying the rectangular area to draw, all coordinates and sizes are
+// in units of 'cells'.  Also, be aware that this function alters the
+// foreground color.
 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)
 {
+    // First fill in the rectangular area...
     x_origin *= nedsim->cell_size;
     x_origin += nedsim->origin_x_offset;
     y_origin *= nedsim->cell_size;
@@ -287,25 +288,29 @@ draw_rect_area(struct NEDsim * nedsim, size_t x_origin, size_t y_origin, size_t
     y_size *= nedsim->cell_size;
     XFillRectangle(nedsim->dpy, nedsim->panel, nedsim->gc, x_origin, y_origin, x_size, y_size);
 
+    // ...then give it a border, if requested.
     set_color(nedsim, &color_list[nedsim->color_index].border);
     if (bord_top) {
-        XFillRectangle(nedsim->dpy, nedsim->panel, nedsim->gc, x_origin, y_origin, x_size, nedsim->border_size);
+        XFillRectangle(nedsim->dpy, nedsim->panel, nedsim->gc,
+                x_origin, y_origin, x_size, nedsim->border_size);
     }
     if (bord_bottom) {
-        XFillRectangle(nedsim->dpy, nedsim->panel, nedsim->gc, x_origin, (y_origin + y_size - nedsim->border_size), x_size, nedsim->border_size);
+        XFillRectangle(nedsim->dpy, nedsim->panel, nedsim->gc,
+                x_origin, (y_origin + y_size - nedsim->border_size), x_size, nedsim->border_size);
     }
     if (bord_left) {
-        XFillRectangle(nedsim->dpy, nedsim->panel, nedsim->gc, x_origin, y_origin, nedsim->border_size, y_size);
+        XFillRectangle(nedsim->dpy, nedsim->panel, nedsim->gc,
+                x_origin, y_origin, nedsim->border_size, y_size);
     }
     if (bord_right) {
-        XFillRectangle(nedsim->dpy, nedsim->panel, nedsim->gc, (x_origin + x_size - nedsim->border_size), y_origin, nedsim->border_size, y_size);
+        XFillRectangle(nedsim->dpy, nedsim->panel, 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.
+// Draws filled circle in a square area with upper left corner at x,y.  When
+// specifying the location and size to draw, all values are in units of
+// 'cells'.  Also, be aware that this function alters the foreground color.
 static void
 draw_circular_area(struct NEDsim * nedsim, size_t x, size_t y, double diameter)
 {
@@ -333,7 +338,27 @@ draw_circular_area(struct NEDsim * nedsim, size_t x, size_t y, double diameter)
     XFillArc(nedsim->dpy, nedsim->panel, nedsim->gc, x, y, diameter, diameter, 0, 360*64);
 }
 
-// TODO: Explain
+// Draws text in a square area with upper left corner at (x_origin,y_origin).
+// Requires that set_font_size() has been run at least once. All values are in
+// units of 'cells'.
+static void
+draw_text(struct NEDsim * nedsim, const char * text, int x_origin, int y_origin, int x_size, int y_size, Bool horizontally_center)
+{
+    set_color(nedsim, &color_list[nedsim->color_index].text);
+
+    int text_x_size, text_y_size;
+    get_text_size(nedsim, text, &text_x_size, &text_y_size);
+
+    int local_y_offset = ((y_size * nedsim->cell_size) - text_y_size) / 2;
+    int local_x_offset = 0;
+    if (horizontally_center) local_x_offset = ((x_size * nedsim->cell_size) - text_x_size) / 2;
+
+    XDrawString(nedsim->dpy, nedsim->panel, nedsim->gc, (x_origin * nedsim->cell_size + nedsim->origin_x_offset + local_x_offset),
+            ((y_origin + y_size) * nedsim->cell_size + nedsim->origin_y_offset - local_y_offset), text, strlen(text));
+}
+
+// Draws the panel itself. Not the lights/labels/etc, but the flat sheet of
+// metal that is the front panel.
 static void
 draw_panel(struct NEDsim * nedsim)
 {
@@ -404,7 +429,7 @@ draw_panel(struct NEDsim * nedsim)
     );
 }
 
-// TODO: Explain
+// Draw the "NED" and "subgeniuskitty.com" logos on the front panel.
 static void
 draw_logo(struct NEDsim * nedsim)
 {
@@ -415,25 +440,15 @@ draw_logo(struct NEDsim * nedsim)
     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->panel, 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);
+    draw_text(nedsim, "NED", LOGO_X_OFFSET, LOGO_Y_OFFSET, LOGO_WIDTH, LOGO_NAME_HEIGHT, True);
 
     // 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->panel, 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);
+    draw_text(nedsim, "subgeniuskitty.com", LOGO_X_OFFSET, LOGO_Y_OFFSET+LOGO_NAME_HEIGHT, LOGO_WIDTH, LOGO_WEBSITE_HEIGHT, True);
 }
 
-// TODO: Explain
+// Draw the HALT indicator area on the front panel.
 static void
 draw_halt(struct NEDsim * nedsim)
 {
@@ -444,16 +459,12 @@ draw_halt(struct NEDsim * nedsim)
     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->panel, 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);
+    draw_text(nedsim, "HALT", HALT_X_OFFSET, HALT_Y_OFFSET+HALT_LIGHT_HEIGHT, HALT_WIDTH, HALT_LABEL_HEIGHT, True);
 }
 
-// TODO: Explain
+// Draw the 32 lights corresponding to 'word' at coordinates ('x','y').
+// Note that this function ONLY draws the lights and is used each frame for
+// updating the panel. To draw the wordline area itself, use draw_wordline().
 static void
 draw_wordline_lights(struct NEDsim * nedsim, uint32_t word, int x, int y)
 {
@@ -467,7 +478,10 @@ draw_wordline_lights(struct NEDsim * nedsim, uint32_t word, int x, int y)
     }
 }
 
-// TODO: Explain
+// Draw a single 32-bit NED word line at coordinates ('x','y').
+// Note that this draws a wordline with value 0. To update with a specific
+// value, call draw_wordline_lights() after drawing the wordline area at least
+// once.
 static void
 draw_wordline(struct NEDsim * nedsim, int x, int y)
 {
@@ -487,7 +501,7 @@ draw_wordline(struct NEDsim * nedsim, int x, int y)
     draw_wordline_lights(nedsim, 0, x, y);
 }
 
-// TODO: Explain
+// Draw the Program Counter area (but don't populate it yet).
 static void
 draw_pc(struct NEDsim * nedsim)
 {
@@ -497,16 +511,10 @@ draw_pc(struct NEDsim * nedsim)
     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->panel, 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);
+    draw_text(nedsim, "PC", PC_X_OFFSET, PC_Y_OFFSET, PC_WIDTH, PC_LABEL_HEIGHT, True);
 }
 
-// TODO: Explain
+// Draw the Stack Counter area (but don't populate it yet).
 static void
 draw_sc(struct NEDsim * nedsim)
 {
@@ -517,16 +525,10 @@ draw_sc(struct NEDsim * nedsim)
     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->panel, 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);
+    draw_text(nedsim, "SC", SC_X_OFFSET, SC_Y_OFFSET, SC_WIDTH, SC_LABEL_HEIGHT, True);
 }
 
-// TODO: Explain
+// Draw areas for the two PSW flags, 'Z'ero and 'N'egative.
 static void
 draw_psw(struct NEDsim * nedsim)
 {
@@ -540,25 +542,12 @@ draw_psw(struct NEDsim * nedsim)
     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->panel, 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->panel, 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);
+    // Now draw the label text.
+    draw_text(nedsim, "N", PSW_N_X_OFFSET, PSW_Y_OFFSET, PSW_LABEL_WIDTH, PSW_LABEL_HEIGHT, True);
+    draw_text(nedsim, "Z", PSW_Z_X_OFFSET, PSW_Y_OFFSET, PSW_LABEL_WIDTH, PSW_LABEL_HEIGHT, True);
 }
 
-// TODO: Explain
+// Draw the stack area (but don't populate it yet).
 static void
 draw_stack(struct NEDsim * nedsim)
 {
@@ -570,15 +559,10 @@ draw_stack(struct NEDsim * nedsim)
     }
 
     // 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->panel, 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);
+    draw_text(nedsim, "Stack Size:", STACK_X_OFFSET+1, STACK_Y_OFFSET, STACK_WIDTH, STACK_LABEL_HEIGHT, False);
 }
 
-// TODO: Explain
+// Draw the heap area (but don't populate it yet).
 static void
 draw_heap(struct NEDsim * nedsim)
 {
@@ -592,25 +576,18 @@ draw_heap(struct NEDsim * nedsim)
         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->panel, 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 text label "RAM Base:".
+    draw_text(nedsim, "RAM Base:", HEAP_X_OFFSET+1, HEAP_Y_OFFSET, HEAP_WIDTH, HEAP_LABEL_HEIGHT, False);
 
     // 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->panel, 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));
+    draw_text(nedsim, address, (HEAP_X_OFFSET+(HEAP_WIDTH/2)+1), HEAP_Y_OFFSET, HEAP_WIDTH, HEAP_LABEL_HEIGHT, False);
 }
 
-// TODO: Explain
+// After the static front panel has been drawn at least once, this function
+// updates all the dynamic parts of the panel (lights + text values) and is
+// called every frame.
 static void
 update_display(struct NEDsim * nedsim)
 {
@@ -666,14 +643,9 @@ update_display(struct NEDsim * nedsim)
     // 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->panel, 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_text(nedsim, stack_size, (STACK_X_OFFSET+(STACK_WIDTH/2)+1), STACK_Y_OFFSET, STACK_WIDTH, STACK_LABEL_HEIGHT, False);
 
     // Draw the heap lights.
     for (i = 0; i < nedsim->num_data_rows; i++) {
@@ -786,8 +758,8 @@ NEDsim_init(Display * dpy, Window win)
     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);
+        if ((nedsim->cell_size * i) > available_space_for_data_rows) {
+            nedsim->num_data_rows = --i;
             break;
         }
     }