X-Git-Url: https://git.ao2.it/libam7xxx.git/blobdiff_plain/81ac15ca7bd31d54a72aea8c93c87bdb49dd272b..a90e2ac0541712553638996d2247046fe5b35001:/src/am7xxx.c

diff --git a/src/am7xxx.c b/src/am7xxx.c
index 30e689f..8087f89 100644
--- a/src/am7xxx.c
+++ b/src/am7xxx.c
@@ -22,6 +22,7 @@
 #include <stdarg.h>
 #include <errno.h>
 #include <libusb.h>
+#include <math.h>
 
 #include "am7xxx.h"
 #include "serialize.h"
@@ -35,6 +36,20 @@
 #  define  __attribute__(x)  /*NOTHING*/
 #endif
 
+/* Control shared library symbols visibility */
+#if defined _WIN32 || defined __CYGWIN__
+	#define AM7XXX_PUBLIC __declspec(dllexport)
+	#define AM7XXX_LOCAL
+#else
+	#if __GNUC__ >= 4
+		#define AM7XXX_PUBLIC __attribute__ ((visibility ("default")))
+		#define AM7XXX_LOCAL  __attribute__ ((visibility ("hidden")))
+	#else
+		#define AM7XXX_PUBLIC
+		#define AM7XXX_LOCAL
+	#endif
+#endif
+
 static void log_message(am7xxx_context *ctx,
 			int level,
 			const char *function,
@@ -69,7 +84,7 @@ static struct am7xxx_usb_device_descriptor supported_devices[] = {
 };
 
 /* The header size on the wire is known to be always 24 bytes, regardless of
- * the memory configuration enforced by different architechtures or compilers
+ * the memory configuration enforced by different architectures or compilers
  * for struct am7xxx_header
  */
 #define AM7XXX_HEADER_WIRE_SIZE 24
@@ -550,7 +565,9 @@ out:
 	return ret;
 }
 
-int am7xxx_init(am7xxx_context **ctx)
+/* Public API */
+
+AM7XXX_PUBLIC int am7xxx_init(am7xxx_context **ctx)
 {
 	int ret = 0;
 
@@ -589,7 +606,7 @@ out:
 	return ret;
 }
 
-void am7xxx_shutdown(am7xxx_context *ctx)
+AM7XXX_PUBLIC void am7xxx_shutdown(am7xxx_context *ctx)
 {
 	am7xxx_device *current;
 
@@ -611,12 +628,12 @@ void am7xxx_shutdown(am7xxx_context *ctx)
 	ctx = NULL;
 }
 
-void am7xxx_set_log_level(am7xxx_context *ctx, am7xxx_log_level log_level)
+AM7XXX_PUBLIC void am7xxx_set_log_level(am7xxx_context *ctx, am7xxx_log_level log_level)
 {
 	ctx->log_level = log_level;
 }
 
-int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
+AM7XXX_PUBLIC int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
 		       unsigned int device_index)
 {
 	int ret;
@@ -638,7 +655,7 @@ int am7xxx_open_device(am7xxx_context *ctx, am7xxx_device **dev,
 	return ret;
 }
 
-int am7xxx_close_device(am7xxx_device *dev)
+AM7XXX_PUBLIC int am7xxx_close_device(am7xxx_device *dev)
 {
 	if (dev == NULL) {
 		fatal("dev must not be NULL!\n");
@@ -652,7 +669,7 @@ int am7xxx_close_device(am7xxx_device *dev)
 	return 0;
 }
 
-int am7xxx_get_device_info(am7xxx_device *dev,
+AM7XXX_PUBLIC int am7xxx_get_device_info(am7xxx_device *dev,
 			   am7xxx_device_info *device_info)
 {
 	int ret;
@@ -691,7 +708,69 @@ int am7xxx_get_device_info(am7xxx_device *dev,
 	return 0;
 }
 
-int am7xxx_send_image(am7xxx_device *dev,
+AM7XXX_PUBLIC 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)
+{
+
+	am7xxx_device_info device_info;
+	float width_ratio;
+	float height_ratio;
+	int ret;
+
+	ret = am7xxx_get_device_info(dev, &device_info);
+	if (ret < 0) {
+		error(dev->ctx, "cannot get device info\n");
+		return ret;
+	}
+
+	/*
+	 * Check if we need to rescale; if the input image fits the native
+	 * dimensions there is no need to, unless we want to upscale.
+	 */
+	if (!upscale &&
+	    original_width <= device_info.native_width &&
+	    original_height <= device_info.native_height ) {
+		debug(dev->ctx, "CASE 0, no rescaling, the original image fits already\n");
+		*scaled_width = original_width;
+		*scaled_height = original_height;
+		return 0;
+	}
+
+	/* Input dimensions relative to the device native dimensions */
+	width_ratio =  (float)original_width / device_info.native_width;
+	height_ratio = (float)original_height / device_info.native_height;
+
+	if (width_ratio > height_ratio) {
+		/*
+		 * The input is proportionally "wider" than the device viewport
+		 * so its height needs to be adjusted
+		 */
+		debug(dev->ctx, "CASE 1, original image wider, adjust the scaled height\n");
+		*scaled_width = device_info.native_width;
+		*scaled_height = (unsigned int)lroundf(original_height / width_ratio);
+	} else if (width_ratio < height_ratio) {
+		/*
+		 * The input is proportionally "taller" than the device viewport
+		 * so its width needs to be adjusted
+		 */
+		debug(dev->ctx, "CASE 2 original image taller, adjust the scaled width\n");
+		*scaled_width = (unsigned int)lroundf(original_width / height_ratio);
+		*scaled_height = device_info.native_height;
+	} else {
+		debug(dev->ctx, "CASE 3, just rescale, same aspect ratio already\n");
+		*scaled_width = device_info.native_width;
+		*scaled_height = device_info.native_height;
+	}
+	debug(dev->ctx, "scaled dimensions: %dx%d\n", *scaled_width, *scaled_height);
+
+	return 0;
+}
+
+AM7XXX_PUBLIC int am7xxx_send_image(am7xxx_device *dev,
 		      am7xxx_image_format format,
 		      unsigned int width,
 		      unsigned int height,
@@ -727,7 +806,7 @@ int am7xxx_send_image(am7xxx_device *dev,
 	return send_data(dev, image, image_size);
 }
 
-int am7xxx_set_power_mode(am7xxx_device *dev, am7xxx_power_mode mode)
+AM7XXX_PUBLIC int am7xxx_set_power_mode(am7xxx_device *dev, am7xxx_power_mode mode)
 {
 	int ret;
 	struct am7xxx_header h = {