X-Git-Url: https://git.ao2.it/libam7xxx.git/blobdiff_plain/dbb6f1e7ec9a0fb7ca077062864767d3b60ef813..15c717cbc1a51c9a5551dc314f9697aa750d6ecb:/src/am7xxx.h diff --git a/src/am7xxx.h b/src/am7xxx.h index 4fe9b00..24636c3 100644 --- a/src/am7xxx.h +++ b/src/am7xxx.h @@ -37,7 +37,7 @@ extern "C" { struct _am7xxx_context; typedef struct _am7xxx_context am7xxx_context; -/** +/** * @typedef am7xxx_device * * An opaque data type representing an am7xxx device. @@ -88,7 +88,7 @@ typedef enum { * An am7xxx device can operate in several power modes. A certain power mode * may have effect on the display brightness or on the device power * consumption. - * + * * @note Most am7xxx devices come with a Y-shaped USB cable with a Master and * a Slave connector, higher power modes may require that both connectors are * plugged in to the host system for the device to work properly. @@ -99,12 +99,30 @@ typedef enum { typedef enum { AM7XXX_POWER_OFF = 0, /**< Display is powered off, no image shown. */ AM7XXX_POWER_LOW = 1, /**< Low power consumption but also low brightness. */ - AM7XXX_POWER_MIDDLE = 2, /**< Middle level of brightness. */ + AM7XXX_POWER_MIDDLE = 2, /**< Middle level of brightness. This and upper modes need both the Master and Slave USB connectors plugged. */ AM7XXX_POWER_HIGH = 3, /**< More brightness, but more power consumption. */ - AM7XXX_POWER_TURBO = 4, /**< Max brightness and power consumprion. This may need both the Master and Slave USB connectors plugged. */ + AM7XXX_POWER_TURBO = 4, /**< Max brightness and power consumption. */ } am7xxx_power_mode; /** + * The display zoom modes. + * + * An am7xxx device can display images using several zoom modes. + * + * @note Changing the zoom mode can change the aspect ratio of the displayed + * image. + * + * @note On the zoom test screen the version of the firmware running on the + * device is shown as well (e.g SPI_V21.0.0_2011.03.18). + */ +typedef enum { + AM7XXX_ZOOM_ORIGINAL = 0, /**< Original Size, as retrieved via #am7xxx_device_info. */ + AM7XXX_ZOOM_H = 1, /**< Zoom 1: H Scale (changes aspect ratio). */ + AM7XXX_ZOOM_H_V = 2, /**< Zoom 2: H/V Scale (changes aspect ratio). */ + AM7XXX_ZOOM_TEST = 3, /**< Zoom test screen, the firmware version is shown as well. */ +} am7xxx_zoom_mode; + +/** * Initialize the library context and data structures, and scan for devices. * * @param[out] ctx A pointer to the context the library will be used in. @@ -179,6 +197,28 @@ int am7xxx_get_device_info(am7xxx_device *dev, am7xxx_device_info *device_info); /** + * Calculate the dimensions of an image to be shown on an am7xxx device. + * + * Before sending images bigger than the device native dimensions the user + * needs to rescale them, this utility function does the calculation in a way + * that the original image aspect ratio is preserved. + * + * @param[in] dev A pointer to the structure representing the device to get info of + * @param[in] upscale Whether to calculate scaled dimensions for images smaller than the native dimensions + * @param[in] original_width The width of the original image + * @param[in] original_height The height of the original image + * @param[out] scaled_width The width the rescaled image should have + * @param[out] scaled_height The height the rescaled image should have + * + * @return 0 on success, a negative value on error + */ +int am7xxx_calc_scaled_image_dimensions(am7xxx_device *dev, + unsigned int upscale, + unsigned int original_width, + unsigned int original_height, + unsigned int *scaled_width, + unsigned int *scaled_height); +/** * Send an image for display on a am7xxx device. * * This is the function that actually makes the device display something. @@ -187,9 +227,9 @@ int am7xxx_get_device_info(am7xxx_device *dev, * * @param[in] dev A pointer to the structure representing the device to get info of * @param[in] format The format the image is in (see @link am7xxx_image_format @endlink enum) - * @param[in] width The width of the image + * @param[in] width The width of the image * @param[in] height The height of the image - * @param[in] image A buffer holding data in the format specified by the format parameter + * @param[in] image A buffer holding data in the format specified by the format parameter * @param[in] image_size The size in bytes of the image buffer * * @return 0 on success, a negative value on error @@ -204,17 +244,38 @@ int am7xxx_send_image(am7xxx_device *dev, /** * Set the power mode of an am7xxx device. * - * \note If we set the mode to AM7XXX_POWER_OFF we can't turn the - * display on again by using only am7xxx_set_power_mode(). This needs to be - * investigated, maybe some other command can reset the device. + * @note When setting the mode to AM7XXX_POWER_OFF the display can't be turned + * on again by using only am7xxx_set_power_mode(), am7xxx_set_zoom_mode() has + * to be called first, the current guess is that the latter performs some + * other resets beside setting the zoom mode. * - * @param[in] dev A pointer to the structure representing the device to get info of - * @param[in] mode The power mode to put the device in (see @link am7xxx_power_mode @endlink enum) + * @param[in] dev A pointer to the structure representing the device to set power mode to + * @param[in] power The power mode to put the device in (see #am7xxx_power_mode enum) + * + * @return 0 on success, a negative value on error + * + */ +int am7xxx_set_power_mode(am7xxx_device *dev, am7xxx_power_mode power); + +/** + * Set the zoom mode of an am7xxx device. + * + * @note When setting the mode to AM7XXX_ZOOM_TEST, the calling program might + * want to skip displaying actual images. + * + * @note It looks like that power mode and zoom mode are related somehow wrt. + * resetting the operational mode after AM7XXX_POWER_OFF, applications can + * restore the display properly using this combination: + * - Off: power mode 0, zoom mode 3 + * - On: power mode != 0, zoom mode != 3 + * + * @param[in] dev A pointer to the structure representing the device to set zoom mode to + * @param[in] zoom The zoom mode to put the device in (see #am7xxx_zoom_mode enum) * * @return 0 on success, a negative value on error * */ -int am7xxx_set_power_mode(am7xxx_device *dev, am7xxx_power_mode mode); +int am7xxx_set_zoom_mode(am7xxx_device *dev, am7xxx_zoom_mode zoom); #ifdef __cplusplus }