###############################################################################
#
# Copyright (c) 2020, NVIDIA CORPORATION. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
#  * Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#  * Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
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#    contributors may be used to endorse or promote products derived
#    from this software without specific prior written permission.
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# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
# EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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# PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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###############################################################################

# Clear the flags from env
CPPFLAGS :=
LDFLAGS :=

# Verbose flag
ifeq ($(VERBOSE), 1)
AT =
else
AT = @
endif

# ARM ABI of the target platform
ifeq ($(TEGRA_ARMABI),)
TEGRA_ARMABI ?= aarch64-linux-gnu
endif

# Location of the target rootfs
ifeq ($(shell uname -m), aarch64)
TARGET_ROOTFS :=
else
ifeq ($(TARGET_ROOTFS),)
$(error Please specify the target rootfs path if you are cross-compiling)
endif
endif

# Use absolute path for better access from everywhere
TOP_DIR := $(shell pwd | awk '{split($$0, f, "/opencv\-sample\-apps"); print f[1]}')

ifeq ($(shell uname -m), aarch64)
CROSS_COMPILE :=
else
CROSS_COMPILE ?= aarch64-unknown-linux-gnu-
endif
AS             = $(AT) $(CROSS_COMPILE)as
LD             = $(AT) $(CROSS_COMPILE)ld
CC             = $(AT) $(CROSS_COMPILE)gcc
CPP            = $(AT) $(CROSS_COMPILE)g++
AR             = $(AT) $(CROSS_COMPILE)ar
NM             = $(AT) $(CROSS_COMPILE)nm
STRIP          = $(AT) $(CROSS_COMPILE)strip
OBJCOPY        = $(AT) $(CROSS_COMPILE)objcopy
OBJDUMP        = $(AT) $(CROSS_COMPILE)objdump

# Specify the logical root directory for headers and libraries.
ifneq ($(TARGET_ROOTFS),)
CPPFLAGS += --sysroot=$(TARGET_ROOTFS)
LDFLAGS += \
	-Wl,-rpath-link=$(TARGET_ROOTFS)/usr/lib \
	-Wl,-rpath-link=$(TARGET_ROOTFS)/lib/$(TEGRA_ARMABI) \
	-Wl,-rpath-link=$(TARGET_ROOTFS)/usr/lib/$(TEGRA_ARMABI)/gstreamer-1.0
endif

# All common header files
CPPFLAGS += -std=c++11 \
	-I"$(TARGET_ROOTFS)/usr/include/$(TEGRA_ARMABI)" \
	-I"$(TARGET_ROOTFS)/usr/include/opencv4"

# All common dependent libraries
LDFLAGS += \
	-lpthread -lopencv_core -lopencv_highgui -lopencv_videoio -lopencv_imgproc \
	-L"$(TARGET_ROOTFS)/usr/lib" \
	-L"$(TARGET_ROOTFS)/usr/lib/$(TEGRA_ARMABI)" \
	-L"$(TARGET_ROOTFS)/usr/lib/$(TEGRA_ARMABI)/gstreamer-1.0"