picoproj: add a note about image dimensions and native resolution

[libam7xxx.git] / src / am7xxx.c

diff --git a/src/am7xxx.c b/src/am7xxx.c
index a8bcc49..8087f89 100644 (file)
--- 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
@@ -244,6 +259,7 @@ static void debug_dump_header(am7xxx_context *ctx, struct am7xxx_header *h)
        (void)ctx;
        (void)h;
 }
+
 static void trace_dump_buffer(am7xxx_context *ctx, const char *message,
                              uint8_t *buffer, unsigned int len)
 {
@@ -549,7 +565,9 @@ out:
        return ret;
 }
 
-int am7xxx_init(am7xxx_context **ctx)
+/* Public API */
+
+AM7XXX_PUBLIC int am7xxx_init(am7xxx_context **ctx)
 {
        int ret = 0;
 
@@ -588,7 +606,7 @@ out:
        return ret;
 }
 
-void am7xxx_shutdown(am7xxx_context *ctx)
+AM7XXX_PUBLIC void am7xxx_shutdown(am7xxx_context *ctx)
 {
        am7xxx_device *current;
 
@@ -610,12 +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;
@@ -637,7 +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");
@@ -651,7 +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;
@@ -690,7 +708,7 @@ int am7xxx_get_device_info(am7xxx_device *dev,
        return 0;
 }
 
-int am7xxx_calc_scaled_image_dimensions(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,
@@ -733,14 +751,14 @@ int am7xxx_calc_scaled_image_dimensions(am7xxx_device *dev,
                 */
                debug(dev->ctx, "CASE 1, original image wider, adjust the scaled height\n");
                *scaled_width = device_info.native_width;
-               *scaled_height = (unsigned int)(original_height / width_ratio);
+               *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)(original_width / height_ratio);
+               *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");
@@ -752,7 +770,7 @@ int am7xxx_calc_scaled_image_dimensions(am7xxx_device *dev,
        return 0;
 }
 
-int am7xxx_send_image(am7xxx_device *dev,
+AM7XXX_PUBLIC int am7xxx_send_image(am7xxx_device *dev,
                      am7xxx_image_format format,
                      unsigned int width,
                      unsigned int height,
@@ -788,7 +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 = {