o Making dropping privileges the default.

o Make it possible to select scan mode programmatically.

examples-api-use/demo-main.cc

@@ -1030,10 +1030,7 @@ static int usage(const char *progname) {
           "\t-R <rotation>             : Sets the rotation of matrix. "
           "Allowed: 0, 90, 180, 270. Default: 0.\n");
 
-  RGBMatrix::Options m_options;
-  rgb_matrix::RuntimeOptions rt_options;
-  rt_options.drop_privileges = 1;
-  rgb_matrix::PrintMatrixFlags(stderr, m_options, rt_options);
+  rgb_matrix::PrintMatrixFlags(stderr);
 
   fprintf(stderr, "Demos, choosen with -D\n");
   fprintf(stderr, "\t0  - some rotating square\n"
@@ -1063,9 +1060,7 @@ int main(int argc, char *argv[]) {
 
   // First things first: create matrix and fish out the command line
   // options it responds to. After that, we parse the remaining options.
-  rgb_matrix::RuntimeOptions rt_options;
-  rt_options.drop_privileges = 1;
-  RGBMatrix *matrix = CreateMatrixFromFlags(&argc, &argv, NULL, &rt_options);
+  RGBMatrix *matrix = CreateMatrixFromFlags(&argc, &argv);
 
   int opt;
   while ((opt = getopt(argc, argv, "dD:t:r:P:c:p:b:m:LR:")) != -1) {

include/led-matrix.h

@@ -78,6 +78,9 @@ class RGBMatrix : public Canvas {
     // Default: 100
     int brightness;
 
+    // Scan mode: 0=progressive, 1=interlaced
+    int scan_mode;
+
     bool show_refresh_rate;
     bool swap_green_blue;
     bool inverse_colors;

lib/Makefile

@@ -9,8 +9,9 @@ TARGET=librgbmatrix
 
 ###
 # After you change any of the following DEFINES, make sure to 'make' again.
-# Note, all these options now can be set programmatically and via command line
-# options as well. So be prepared for these to be removed.
+#
+# Note, most of these options now can be set programmatically and via command
+# line options as well. So be prepared for these to be removed.
 ###
 
 # If you see that your display is inverse, you might have a matrix variant

lib/framebuffer-internal.h

@@ -28,6 +28,7 @@ namespace internal {
 class Framebuffer {
 public:
   Framebuffer(int rows, int columns, int parallel,
+              int scan_mode,
               bool swap_green_blue, bool inverse_color);
   ~Framebuffer();
 
@@ -70,6 +71,7 @@ class Framebuffer {
   const int height_;   // rows * parallel
   const int columns_;  // Number of columns. Number of chained boards * 32.
 
+  const int scan_mode_;
   const bool swap_green_blue_;
   const bool inverse_color_;
 

lib/framebuffer.cc

@@ -62,11 +62,13 @@ static PinPulser *sOutputEnablePulser = NULL;
 #endif
 
 Framebuffer::Framebuffer(int rows, int columns, int parallel,
+                         int scan_mode,
                          bool swap_green_blue, bool inverse_color)
   : rows_(rows),
     parallel_(parallel),
     height_(rows * parallel),
     columns_(columns),
+    scan_mode_(scan_mode),
     swap_green_blue_(swap_green_blue), inverse_color_(inverse_color),
     pwm_bits_(kBitPlanes), do_luminance_correct_(true), brightness_(100),
     double_rows_(rows / SUB_PANELS_), row_mask_(double_rows_ - 1) {
@@ -351,23 +353,28 @@ void Framebuffer::DumpToMatrix(GPIO *io) {
   clock.bits.clock = 1;
   strobe.bits.strobe = 1;
 
-#if RGB_SCAN_INTERLACED
+  // info needed for interlace mode.
   uint8_t rot_bits = 0;
   switch (double_rows_) {
   case  4: rot_bits = 1; break;
   case  8: rot_bits = 2; break;
   case 16: rot_bits = 3; break;
   case 32: rot_bits = 4; break;
   }
-#endif
 
   const int pwm_to_show = pwm_bits_;  // Local copy, might change in process.
   for (uint8_t row_loop = 0; row_loop < double_rows_; ++row_loop) {
-#if RGB_SCAN_INTERLACED
-    uint8_t d_row = ((row_loop << 1) | (row_loop >> rot_bits)) & row_mask_;
-#else
-    uint8_t d_row = row_loop;
-#endif
+    uint8_t d_row;
+    switch (scan_mode_) {
+    case 0:  // progressive
+    default:
+      d_row = row_loop;
+      break;
+
+    case 1:  // interlaced
+      d_row = ((row_loop << 1) | (row_loop >> rot_bits)) & row_mask_;
+    }
+
     row_address.bits.a = d_row;
     row_address.bits.b = d_row >> 1;
     row_address.bits.c = d_row >> 2;

lib/led-matrix.cc

@@ -122,6 +122,12 @@ RGBMatrix::Options::Options()
   : rows(32), chain_length(1), parallel(1), pwm_bits(11), brightness(100),
     // Historically, we provided these options only as #defines. Make sure that
     // things still behave as before if someone has set these.
+#ifdef RGB_SCAN_INTERLACED
+    scan_mode(1),
+#else
+    scan_mode(0),
+#endif
+
 #ifdef SHOW_REFRESH_RATE
     show_refresh_rate(true),
 #else
@@ -204,6 +210,7 @@ FrameCanvas *RGBMatrix::CreateFrameCanvas() {
     new FrameCanvas(new internal::Framebuffer(params_.rows,
                                               32 * params_.chain_length,
                                               params_.parallel,
+                                              params_.scan_mode,
                                               params_.swap_green_blue,
                                               params_.inverse_colors));
   if (created_frames_.empty()) {

lib/options-initialize.cc

@@ -32,7 +32,8 @@ RuntimeOptions::RuntimeOptions() :
 #else
   gpio_slowdown(1),
 #endif
-  daemon(0), drop_privileges(0)
+  daemon(0),            // Don't become a daemon by default.
+  drop_privileges(1)    // Encourage good practice: drop privileges by default.
 {
   // Nothing to see here.
 }
@@ -117,6 +118,8 @@ static bool FlagInit(int &argc, char **&argv,
         continue;
       if (ConsumeIntFlag("brightness", it, end, &mopts->brightness, &err))
         continue;
+      if (ConsumeIntFlag("scan-mode", it, end, &mopts->scan_mode, &err))
+        continue;
       if (ConsumeIntFlag("pwm-bits", it, end, &mopts->pwm_bits, &err))
         continue;
       if (ConsumeBoolFlag("show-refresh", it, &mopts->show_refresh_rate))
@@ -250,13 +253,15 @@ void PrintMatrixFlags(FILE *out, const RGBMatrix::Options &d,
           "chains. range=1..3 (Default: %d).\n"
           "\t--led-pwm-bits=<1..11>    : PWM bits (Default: %d).\n"
           "\t--led-brightness=<percent>: Brightness in percent (Default: %d).\n"
+          "\t--led-scan-mode=<0..1>    : 0 = progressive; 1 = interlaced "
+          "(Default: %d).\n"
           "\t--led-%sshow-refresh        : %show refresh rate.\n"
           "\t--led-%sinverse             "
           ": Switch if your matrix has inverse colors %s.\n "
           "\t--led-%sswap-green-blue     : Switch if your matrix has green/blue "
           "swapped %s.\n",
           d.rows, d.chain_length, d.parallel,
-          d.pwm_bits, d.brightness,
+          d.pwm_bits, d.brightness, d.scan_mode,
           d.show_refresh_rate ? "no-" : "", d.show_refresh_rate ? "Don't s" : "S",
           d.inverse_colors ? "no-" : "",    d.inverse_colors ? "off" : "on",
           d.swap_green_blue ? "no-" : "",    d.swap_green_blue ? "off" : "on"
@@ -274,7 +279,7 @@ void PrintMatrixFlags(FILE *out, const RGBMatrix::Options &d,
   if (r.drop_privileges >= 0) {
     const bool on = (r.drop_privileges > 0);
     fprintf(out,
-            "\t--led-%sdrop-privs          : %srop privileges from 'root' "
+            "\t--led-%sdrop-privs       : %srop privileges from 'root' "
             "after initializing the hardware.\n",
             on ? "no-" : "", on ? "Don't d" : "D");
   }
@@ -289,25 +294,29 @@ bool RGBMatrix::Options::Validate(std::string *err) {
   }
 
   if (chain_length < 1) {
-    err->append("Chain-length outside usable range\n");
+    err->append("Chain-length outside usable range.\n");
     success = false;
   }
 
   if (parallel < 1 || parallel > 3) {
-    err->append("Parallel outside usable range.\n");
+    err->append("Parallel outside usable range (1..3 allowed).\n");
     success = false;
   }
 
   if (brightness < 1 || brightness > 100) {
-    err->append("Brightness is outside usable range.\n");
+    err->append("Brightness outside usable range (Percent 1..100 allowed).\n");
     success = false;
   }
 
   if (pwm_bits <= 0 || pwm_bits > 11) {
-    err->append("Invalid range of pwm-bits\n");
+    err->append("Invalid range of pwm-bits (0..11 allowed).\n");
     success = false;
   }
 
+  if (scan_mode < 0 || scan_mode > 1) {
+    err->append("Invalid scan mode (0 or 1 allowed).\n");
+    success = false;
+  }
   return success;
 }