Add ability to control IR projector brightness - fixes #433

Signed-off-by: Benn Snyder <benn.snyder@gmail.com>

Author: piedar

examples/glview.c

@@ -237,6 +237,16 @@ void keyPressed(unsigned char key, int x, int y)
 		freenect_set_flag(f_dev, FREENECT_NEAR_MODE, near_mode);
 		near_mode = near_mode ? FREENECT_OFF : FREENECT_ON;
 	}
+
+	if (key == '+') {
+		uint16_t brightness = freenect_get_ir_brightness(f_dev) + 2;
+		freenect_set_ir_brightness(f_dev, brightness);
+	}
+	if (key == '-') {
+		uint16_t brightness = freenect_get_ir_brightness(f_dev) - 2;
+		freenect_set_ir_brightness(f_dev, brightness);
+	}
+
 	if (key == '1') {
 		freenect_set_led(f_dev,LED_GREEN);
 	}
@@ -259,6 +269,7 @@ void keyPressed(unsigned char key, int x, int y)
 	if (key == '0') {
 		freenect_set_led(f_dev,LED_OFF);
 	}
+
 	if (key == 'o') {
 	    if (camera_rotate) {
 	        camera_rotate = 0;
@@ -420,7 +431,7 @@ void *freenect_threadfunc(void *arg)
 	freenect_start_depth(f_dev);
 	freenect_start_video(f_dev);
 
-	printf("'w' - tilt up, 's' - level, 'x' - tilt down, '0'-'6' - select LED mode \n");
+	printf("'w' - tilt up, 's' - level, 'x' - tilt down, '0'-'6' - select LED mode, '+' & '-' - change IR intensity \n");
 	printf("'f' - change video format, 'm' - mirror video, 'o' - rotate video with accelerometer \n");
 	printf("'e' - auto exposure, 'b' - white balance, 'r' - raw color, 'n' - near mode (K4W only) \n");
 

include/libfreenect.h

@@ -670,6 +670,24 @@ FREENECTAPI int freenect_set_depth_mode(freenect_device* dev, const freenect_fra
  */
 FREENECTAPI int freenect_set_flag(freenect_device *dev, freenect_flag flag, freenect_flag_value value);
 
+/**
+ * Returns the brightness of the IR projector
+ *
+ * @param dev Device to get IR brightness
+ *
+ * @return IR brightness, UINT16_MAX if error
+ */
+FREENECTAPI uint16_t freenect_get_ir_brightness(freenect_device *dev);
+
+/**
+ * Sets the brightness of the IR projector
+ *
+ * @param dev Device to set IR brightness
+ * @param brighness Brightness value in range 1 - 50
+ *
+ * @return 0 on success, < 0 if error
+ */
+FREENECTAPI int freenect_set_ir_brightness(freenect_device *dev, uint16_t brightness);
 
 /**
  * Allows the user to specify a pointer to the audio firmware in memory for the Xbox 360 Kinect

src/flags.c

@@ -30,9 +30,6 @@
 #include "flags.h"
 
 
-// freenect_set_flag is the only function exposed in libfreenect.h
-// The rest are available internally via #include flags.h
-
 FN_INTERNAL int register_for_flag(int flag)
 {
     switch(flag)
@@ -96,6 +93,41 @@ int freenect_set_flag(freenect_device *dev, freenect_flag flag, freenect_flag_va
 	return write_cmos_register(dev, 0x0106, cmos_value);
 }
 
+uint16_t freenect_get_ir_brightness(freenect_device *dev)
+{
+	freenect_context *ctx = dev->parent;
+
+	const uint16_t brightness = read_register(dev, 0x15);
+	if (brightness == UINT16_MAX)
+	{
+		FN_WARNING("Failed to get IR brightness!");
+	}
+
+	return brightness;
+}
+
+int freenect_set_ir_brightness(freenect_device *dev, uint16_t brightness)
+{
+	freenect_context *ctx = dev->parent;
+
+	if (brightness < 1)
+	{
+		brightness = 1;
+	}
+	if (brightness > 50)
+	{
+		brightness = 50;
+	}
+
+	const int ret = write_register(dev, 0x15, brightness);
+	if (ret < 0)
+	{
+		FN_WARNING("Failed to set IR brightness");
+	}
+
+	return ret;
+}
+
 typedef struct {
 	uint8_t magic[2];
 	uint16_t len;