keystone: Report matrix error. Deal with "primary" in xrandr output

Compute the error cause by the fixed point matrix representation and
display that.

Accept the 'primary' word found in xrandr output and ignore it.

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

1 files changed, 101 insertions, 15 deletions

diff --git a/keystone.5c b/keystone.5c
index a292931..f73aa8b 100644
--- a/keystone.5c
+++ b/keystone.5c
@@ -354,16 +354,17 @@ rescale (m_t m, real limit)
 string
 m_print (m_t m)
 {
-    /*
+
     return sprintf ("%.8f,%.8f,%.8f,%.8f,%.8f,%.8f,%.8f,%.8f,%.8f",
 		    m[0,0],m[0,1],m[0,2],
 		    m[1,0],m[1,1],m[1,2],
 		    m[2,0],m[2,1],m[2,2]);
-     */
+/*
     return sprintf ("%v,%v,%v,%v,%v,%v,%v,%v,%v",
 		    m[0,0],m[0,1],m[0,2],
 		    m[1,0],m[1,1],m[1,2],
 		    m[2,0],m[2,1],m[2,2]);
+*/
 }
 
 int
@@ -372,6 +373,33 @@ fixed (real x)
     return floor (x * 65536 + 0.5) & 0xffffffff;
 }
 
+m_t
+to_fixed(m_t m)
+{
+    m_t r;
+
+    for (int i = 0; i < 3; i++)
+        for (int j = 0; j < 3; j++)
+            r[i,j] = floor(m[i,j] * 65536 + 0.5) / 65536;
+    return r;
+}
+
+m_t
+error(m_t r, m_t f)
+{
+    m_t e;
+
+    for (int i = 0; i < 3; i++)
+        for (int j = 0; j < 3; j++) {
+            real diff = abs(r[i,j] - f[i,j]);
+            if (r[i,j] != 0)
+                e[i,j] = diff / abs(r[i,j]);
+            else
+                e[i,j] = 0;
+        }
+    return e;
+}
+
 void
 m_print_fix (m_t m)
 {
@@ -382,6 +410,55 @@ m_print_fix (m_t m)
     }
 }
 
+real[2]
+map(m_t m, real x, real y)
+{
+    real[3]     in = { x, y, 1 };
+    real[3]     out = { 0 ... };
+
+    for (int i = 0; i < 3; i++) {
+        for (int j = 0; j < 3; j++)
+            out[i] += m[i,j] * in[j];
+    }
+    return (real[2]) { out[0] / out[2], out[1]/ out[2] };
+}
+
+real
+position_error(m_t r, m_t f, real x, real y)
+{
+    real[2]     p_r = map(r, x, y);
+    real[2]     p_f = map(f, x, y);
+    real        error;
+
+    error = sqrt((p_r[0] - p_f[0]) ** 2 + (p_r[1] - p_f[1]) ** 2);
+    printf ("x: %g y: %g error %g\n", x, y, error);
+    printf ("\treal x: %g y: %g\n", p_r[0], p_r[1]);
+    printf ("\tfix  x: %g y: %g\n", p_f[0], p_f[1]);
+    return error;
+}
+
+real
+max_error(m_t r, m_t f) {
+    real        max = 0, max_x = 0, max_y = 0;
+
+    for (int x = 0; x <= 2560; x += 2560)
+        for (int y = 0; y <= 1600; y += 1600) {
+            real error = position_error(r, f, x, y);
+            if (error > max) {
+                max = error;
+                max_x = x;
+                max_y = y;
+            }
+        }
+    printf ("max error %g at %d, %d\n", max, max_x, max_y);
+    real[2] p_r = map(r, max_x ,max_y);
+    real[2] p_f = map(f, max_x, max_y);
+    printf ("\tdesired %7.2f, %7.2f actual %7.2f, %7.2f\n",
+            p_r[0], p_r[1],
+            p_f[0], p_f[1]);
+    return max;
+}
+
 string
 m_row (m_t m, int row)
 {
@@ -414,18 +491,22 @@ output_t[*] get_outputs () {
     {
 	while (!File::end (randr)) {
 	    string[*] words = String::wordsplit (File::fgets (randr), " ");
-	    if (dim (words) >= 3 && words[1] == "connected" &&
-		File::sscanf (words[2], "%dx%d+%d+%d", 
-			&(int width), &(int height), 
-			&(int x), &(int y)) == 4)
-	    {
-		outputs[dim(outputs)] = (output_t) {
-		    name = words[0],
-		    geometry = { 
-			x = x, y = y, width = width, height = height 
-		    }
-		};
-	    }
+	    if (dim (words) >= 3 && words[1] == "connected") {
+                int     geom = 2;
+                if (words[geom] == "primary")
+                    geom++;
+		if (File::sscanf (words[geom], "%dx%d+%d+%d", 
+                                  &(int width), &(int height), 
+                                  &(int x), &(int y)) == 4)
+                {
+                    outputs[dim(outputs)] = (output_t) {
+                        name = words[0],
+                        geometry = { 
+                            x = x, y = y, width = width, height = height 
+                        }
+                    };
+                }
+            }
 	}
     }
     return outputs;
@@ -433,7 +514,7 @@ output_t[*] get_outputs () {
 
 void main ()
 {
-    m_t	m = { { 1, 0, 0 }, { 0, 1, 0 }, { 0, 0, 1 } }, m_i, m_r;
+    m_t	m = { { 1, 0, 0 }, { 0, 1, 0 }, { 0, 0, 1 } }, m_i, m_r, m_f, m_e;
     bool m_available = true;
     output_t[*]	outputs = get_outputs ();
     output_t	target_output;
@@ -529,8 +610,13 @@ void main ()
 	    printf ("normal:  %s\n", m_print (m));
 	    printf ("inverse: %s\n", m_print (m_i));
 	    printf ("scaled:  %s\n", m_print (m_r));
+            m_f = to_fixed(m_r);
+            printf ("round:   %s\n", m_print(m_f));
 	    printf ("fixed:\n");
 	    m_print_fix (m_i);
+            m_e = error(m_r, m_f);
+            printf ("error:   %s\n", m_print (m_e));
+            max_error(m_r, m_f);
 	}
     }