Fix weird corners on ufqfpn28

These have a hack to make the corners step to approximate a diagonal
line, but they were being drawn wrong, leaving too little space
between the corner and adjacent pads.

Signed-off-by: Keith Packard <keithp@keithp.com>

diff --git a/packages/ufqfpn28.5c b/packages/ufqfpn28.5c
index c1b15acf5c2eab7fb1c21111cfc89ae43b2f098c..5a060c8c7d3e5c0bf0ea98c70d4832f4499523e2 100644 (file)
--- a/packages/ufqfpn28.5c
+++ b/packages/ufqfpn28.5c
@@ -21,17 +21,32 @@ import Footprint;
 real pad_width = 0.55;
 real corner_pad_width = 0.50;
 real pad_height = 0.30;
-real corner_pad_notch = 0.12;
+
+/* Required clearance between corner pads on the diagonal */
+real corner_diag_clearance = 0.21;
+
+/* horizontal/vertical size of corner cut out */
+#real corner_pad_notch = corner_diag_clearance / sqrt(2);
+real corner_pad_notch = 0.15;
+
+real corner_pad_minimum_height = pad_height - corner_pad_notch;
+real corner_pad_minimum_width = corner_pad_width - corner_pad_notch;
+
 real pad_spacing = 0.50;
 
-real pad_x_off = 3.20 / 2;
-real pad_y_off = 3.20 / 2;
+/* outer location of pad */
+
+real pad_x_off = (3.30 + 2 * 0.5) / 2;
+real pad_y_off = (3.30 + 2 * 0.5) / 2;
 
 real package_width = 4;
 real package_height = 4;
 
 real num_pad = 7;      /* per side */
 
+/* our magic corner pads appear too narrow */
+override("pad trace");
+
 element_start("ufqfpn-28");
 
 real pad_off(int n) {
@@ -47,15 +62,17 @@ real corner(int dx, int dy) {
        line(x, y, x, y - dy * len);
 }
 
+/*
 corner(-1, -1);
 corner(1, -1);
 corner(-1, 1);
 corner(1, 1);
+*/
 
 real dot_off = .3;
 
-line(-package_width/2 + dot_off, -package_height/2 + dot_off,
-     -package_width/2 + dot_off, -package_height/2 + dot_off);
+line(-package_width/2 - dot_off, -package_height/2 - dot_off,
+     -package_width/2 - dot_off, -package_height/2 - dot_off);
 
 for (int pad = 0; pad < num_pad; pad++) {
        real pw = pad_width;
@@ -69,51 +86,60 @@ for (int pad = 0; pad < num_pad; pad++) {
                nstep = 4;
 
        for (int s = 0; s <= nstep; s++) {
-               if (nstep != 0) {
-                       real    step = (corner_pad_notch) / nstep;
 
-                       pw = corner_pad_width - (nstep - s) * step;
-                       ph = pad_height - s * step*2/3;
+               real    pad_x, pad_y, pad_w, pad_h;
 
-                       pwa = pad_width - pw;
-
-                       pha = pad_height - ph;
-                       if (pad != 0)
-                               pha = -pha;
+               if (nstep != 0) {
+                       real    ratio = s / nstep;
+
+                       pad_x = 0;
+                       if (pad == 0) {
+                               pad_y = -pad_height / 2 * (1-ratio) + ((-pad_height / 2) + corner_pad_notch) * ratio;
+                       } else {
+                               pad_y = -pad_height / 2;
+                       }
+                       pad_w = corner_pad_minimum_width * (1-ratio) + corner_pad_width * ratio;
+
+                       pad_h = pad_height * (1 - ratio) + corner_pad_minimum_height * ratio;
+               } else {
+                       pad_x = 0;
+                       pad_y = -pad_height / 2;
+                       pad_w = pad_width;
+                       pad_h = pad_height;
                }
 
                /* left (1-7) */
-               pad_mm(-pad_x_off - pw / 2 - pwa,
-                      pad_off(pad) + pha,
-                      pw,
-                      ph,
+               pad_mm(-pad_x_off + pad_x + pad_w / 2,
+                      pad_off(pad) + pad_y + pad_h / 2,
+                      pad_w,
+                      pad_h,
                       sprintf("%d", pad + 1),
                       sprintf("%d", pad + 1));
 
                /* bottom (8-14) */
 
-               pad_mm(pad_off(pad) + pha,
-                      pad_y_off + pw / 2 + pwa,
-                      ph,
-                      pw,
+               pad_mm(pad_off(pad) + pad_y + pad_h / 2,
+                      pad_y_off + pad_x - pad_w / 2,
+                      pad_h,
+                      pad_w,
                       sprintf("%d", pad + 8),
                       sprintf("%d", pad + 8));
 
                /* right side (15-21) */
 
-               pad_mm(pad_x_off + pw / 2 + pwa,
-                      -pad_off(pad) - pha,
-                      pw,
-                      ph,
+               pad_mm(pad_x_off - pad_x - pad_w / 2,
+                      -pad_off(pad) - pad_y - pad_h / 2,
+                      pad_w,
+                      pad_h,
                       sprintf("%d", pad + 15),
                       sprintf("%d", pad + 15));
 
                /* top (22-28) */
 
-               pad_mm(-pad_off(pad) - pha,
-                      -pad_y_off - pw / 2 - pwa,
-                      ph,
-                      pw,
+               pad_mm(-pad_off(pad) - pad_y - pad_h / 2,
+                      -pad_y_off - pad_x + pad_w / 2,
+                      pad_h,
+                      pad_w,
                       sprintf("%d", pad + 22),
                       sprintf("%d", pad + 22));
        }