Add support for device-to-screen mapping

xinput map-to-crtc "device name" "VGA0" will map to the CRTC "VGA0" by
manipulating the transformation matrix accordingly. And because the NVIDIA
binary driver still exists, Xinerama is supported to. Maybe in another 5
years, they'll catch up.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
Reviewed-by: Simon Thum <simon.thum@gmx.de>

4 files changed, 269 insertions, 1 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index c33fae3..985207b 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -27,7 +27,7 @@ xinput_LDADD = $(XINPUT_LIBS)
 
 
 if HAVE_XI2
-xinput2_files = hierarchy.c setcp.c test_xi2.c
+xinput2_files = hierarchy.c setcp.c test_xi2.c transform.c
 endif
 
 xinput_SOURCES = \
diff --git a/src/transform.c b/src/transform.c
new file mode 100644
index 0000000..c1a065f
--- /dev/null
+++ b/src/transform.c
@@ -0,0 +1,263 @@
+/*
+ * Copyright © 2011 Red Hat, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+
+#include "xinput.h"
+#include <string.h>
+#include <X11/extensions/Xrandr.h>
+#include <X11/extensions/Xinerama.h>
+
+
+typedef struct Matrix {
+    float m[9];
+} Matrix;
+
+static void matrix_set(Matrix *m, int row, int col, float val)
+{
+    m->m[row * 3 + col] = val;
+}
+
+static void matrix_set_unity(Matrix *m)
+{
+    memset(m, 0, sizeof(m->m));
+    matrix_set(m, 0, 0, 1);
+    matrix_set(m, 1, 1, 1);
+    matrix_set(m, 2, 2, 1);
+}
+
+#if DEBUG
+static void matrix_print(const Matrix *m)
+{
+    printf("[ %3.3f %3.3f %3.3f ]\n", m->m[0], m->m[1], m->m[2]);
+    printf("[ %3.3f %3.3f %3.3f ]\n", m->m[3], m->m[4], m->m[5]);
+    printf("[ %3.3f %3.3f %3.3f ]\n", m->m[6], m->m[7], m->m[8]);
+}
+#endif
+
+static int
+apply_matrix(Display *dpy, int deviceid, Matrix *m)
+{
+    Atom prop_float, prop_matrix;
+
+    union {
+        unsigned char *c;
+        float *f;
+    } data;
+    int format_return;
+    Atom type_return;
+    unsigned long nitems;
+    unsigned long bytes_after;
+
+    int rc;
+
+    prop_float = XInternAtom(dpy, "FLOAT", False);
+    prop_matrix = XInternAtom(dpy, "Coordinate Transformation Matrix", False);
+
+    if (!prop_float)
+    {
+        fprintf(stderr, "Float atom not found. This server is too old.\n");
+        return EXIT_FAILURE;
+    }
+    if (!prop_matrix)
+    {
+        fprintf(stderr, "Coordinate transformation matrix not found. This "
+                "server is too old\n");
+        return EXIT_FAILURE;
+    }
+
+    rc = XIGetProperty(dpy, deviceid, prop_matrix, 0, 9, False, prop_float,
+                       &type_return, &format_return, &nitems, &bytes_after,
+                       &data.c);
+    if (rc != Success || prop_float != type_return || format_return != 32 ||
+        nitems != 9 || bytes_after != 0)
+    {
+        fprintf(stderr, "Failed to retrieve current property values\n");
+        return EXIT_FAILURE;
+    }
+
+    memcpy(data.f, m->m, sizeof(m->m));
+
+    XIChangeProperty(dpy, deviceid, prop_matrix, prop_float,
+                     format_return, PropModeReplace, data.c, nitems);
+
+    XFree(data.c);
+
+    return EXIT_SUCCESS;
+}
+
+static void
+set_transformation_matrix(Display *dpy, Matrix *m, int offset_x, int offset_y,
+                                int screen_width, int screen_height)
+{
+    /* offset */
+    int width = DisplayWidth(dpy, DefaultScreen(dpy));
+    int height = DisplayHeight(dpy, DefaultScreen(dpy));
+
+    /* offset */
+    float x = 1.0 * offset_x/width;
+    float y = 1.0 * offset_y/height;
+
+    /* mapping */
+    float w = 1.0 * screen_width/width;
+    float h = 1.0 * screen_height/height;
+
+    matrix_set_unity(m);
+
+    matrix_set(m, 0, 2, x);
+    matrix_set(m, 1, 2, y);
+
+    matrix_set(m, 0, 0, w);
+    matrix_set(m, 1, 1, h);
+
+#if DEBUG
+    matrix_print(m);
+#endif
+}
+
+static int
+map_crtc_xrandr(Display *dpy, int deviceid, const char *output_name)
+{
+    int i, found = 0;
+    int rc = EXIT_FAILURE;
+    XRRScreenResources *res;
+    XRROutputInfo *output_info;
+    XRRCrtcInfo *crtc_info;
+
+    res = XRRGetScreenResources(dpy, DefaultRootWindow(dpy));
+
+    for (i = 0; i < res->noutput && !found; i++)
+    {
+        output_info = XRRGetOutputInfo(dpy, res, res->outputs[i]);
+        if (!output_info->crtc || output_info->connection != RR_Connected)
+            continue;
+
+        crtc_info = XRRGetCrtcInfo (dpy, res, output_info->crtc);
+        if (strcmp(output_info->name, output_name) == 0)
+        {
+            found = 1;
+            break;
+        }
+    }
+
+    /* crtc holds our screen info, need to compare to actual screen size */
+    if (found)
+    {
+        Matrix m;
+        matrix_set_unity(&m);
+        set_transformation_matrix(dpy, &m, crtc_info->x, crtc_info->y,
+                                  crtc_info->width, crtc_info->height);
+        rc = apply_matrix(dpy, deviceid, &m);
+    } else
+        printf("Unable to find output '%s'. "
+                "Output may not be connected.\n", output_name);
+
+    XRRFreeScreenResources(res);
+
+    return rc;
+}
+
+static int
+map_crtc_xinerama(Display *dpy, int deviceid, const char *output_name)
+{
+    const char *prefix = "HEAD-";
+    XineramaScreenInfo *screens = NULL;
+    int rc = EXIT_FAILURE;
+    int event, error;
+    int nscreens;
+    int head;
+    Matrix m;
+
+    if (!XineramaQueryExtension(dpy, &event, &error))
+    {
+        fprintf(stderr, "Unable to set screen mapping. Xinerama extension not found\n");
+        goto out;
+    }
+
+    if (strlen(output_name) < strlen(prefix) + 1 ||
+        strncmp(output_name, prefix, strlen(prefix)) != 0)
+    {
+        fprintf(stderr, "Please specify the output name as HEAD-X,"
+                "where X is the screen number\n");
+        goto out;
+    }
+
+    head = output_name[strlen(prefix)] - '0';
+
+    screens = XineramaQueryScreens(dpy, &nscreens);
+
+    if (nscreens == 0)
+    {
+        fprintf(stderr, "Xinerama failed to query screens.\n");
+        goto out;
+    } else if (nscreens <= head)
+    {
+        fprintf(stderr, "Found %d screens, but you requested %s.\n",
+                nscreens, output_name);
+        goto out;
+    }
+
+    matrix_set_unity(&m);
+    set_transformation_matrix(dpy, &m,
+                              screens[head].x_org, screens[head].y_org,
+                              screens[head].width, screens[head].height);
+    rc = apply_matrix(dpy, deviceid, &m);
+
+out:
+    XFree(screens);
+    return rc;
+}
+
+int
+map_to_crtc(Display *dpy, int argc, char *argv[], char *name, char *desc)
+{
+    int opcode, event, error;
+    int maj, min;
+    char *crtc_name;
+    XIDeviceInfo *info;
+
+    if (argc < 2)
+    {
+        fprintf(stderr, "Usage: xinput %s %s\n", name, desc);
+        return EXIT_FAILURE;
+    }
+
+    info = xi2_find_device_info(dpy, argv[0]);
+    if (!info)
+    {
+        fprintf(stderr, "unable to find device %s\n", argv[0]);
+        return EXIT_FAILURE;
+    }
+
+    crtc_name = argv[1];
+
+    /* Check for RandR 1.2. Server bug causes the NVIDIA driver to
+     * report with RandR 1.3 support but it doesn't expose RandR CRTCs.
+     * Force Xinerama if NV-CONTROL is present */
+    if (XQueryExtension(dpy, "NV-CONTROL", &opcode, &event, &error) ||
+        !XQueryExtension(dpy, "RANDR", &opcode, &event, &error) ||
+        !XRRQueryVersion(dpy, &maj, &min) || (maj * 1000 + min) < 1002)
+       return map_crtc_xinerama(dpy, info->deviceid, crtc_name);
+    else
+       return map_crtc_xrandr(dpy, info->deviceid, crtc_name);
+}
diff --git a/src/xinput.c b/src/xinput.c
index 64b4887..432cffc 100644
--- a/src/xinput.c
+++ b/src/xinput.c
@@ -104,6 +104,10 @@ static entry drivers[] =
       "<device>",
       test_xi2,
     },
+    { "map-to-crtc",
+      "<device> <crtc name>",
+      map_to_crtc,
+    },
 #endif
     { "list-props",
       "<device> [<device> ...]",
diff --git a/src/xinput.h b/src/xinput.h
index d44ce09..94b8f3c 100644
--- a/src/xinput.h
+++ b/src/xinput.h
@@ -77,5 +77,6 @@ int change_attachment( Display* display, int argc, char *argv[], char *prog_name
 int float_device( Display* display, int argc, char *argv[], char *prog_name, char *prog_desc);
 int set_clientpointer( Display* display, int argc, char *argv[], char *prog_name, char *prog_desc);
 int test_xi2( Display* display, int argc, char *argv[], char *prog_name, char *prog_desc);
+int map_to_crtc( Display* display, int argc, char *argv[], char *prog_name, char *prog_desc);
 
 /* end of xinput.h */