* builds/freetype.mk: Add rule 'refdoc-venv'.

Add new rule `refdoc-venv' for building documentation in python
virtualenv. This is an ongoing discussion at:

  http://lists.nongnu.org/archive/html/freetype-devel/2018-07/msg00209.html

* builds/freetype.mk: Add rule `refdoc-venv'
* builds/{os}/*-def.mk: Add variable `BIN' for virtualenv.

builds/ansi/ansi-def.mk

@@ -16,6 +16,7 @@
 DELETE    := rm -f
 CAT       := cat
 SEP       := /
+BIN       := bin
 BUILD_DIR := $(TOP_DIR)/builds/ansi
 PLATFORM  := ansi
 

builds/beos/beos-def.mk

@@ -18,6 +18,7 @@
 DELETE    := rm -f
 CAT       := cat
 SEP       := /
+BIN       := bin
 BUILD_DIR := $(TOP_DIR)/builds/beos
 PLATFORM  := beos
 

builds/dos/dos-def.mk

@@ -16,6 +16,7 @@
 DELETE    := del
 CAT       := type
 SEP       := $(strip \ )
+BIN       := Scripts
 BUILD_DIR := $(TOP_DIR)/builds/dos
 PLATFORM  := dos
 

builds/freetype.mk

@@ -75,7 +75,7 @@
 # The targets `objects' and `library' are defined at the end of this
 # Makefile after all other rules have been included.
 #
-.PHONY: single multi objects library refdoc
+.PHONY: single multi objects library refdoc refdoc-venv
 
 # default target -- build single objects and library
 #
@@ -308,6 +308,28 @@ refdoc:
 	cd $(DOC_DIR) && mkdocs build
 	@echo Done.
 
+VENV_NAME     := env
+VENV_ACTIVATE := $(VENV_NAME)$(SEP)$(BIN)$(SEP)activate
+PYTHON        := $(VENV_NAME)$(SEP)$(BIN)$(SEP)python
+PIP           := $(VENV_NAME)$(SEP)$(BIN)$(SEP)pip
+
+refdoc-venv:
+	@echo Setting up virtualenv for Python...
+	virtualenv $(VENV_NAME)
+	@echo Installing requirements...
+	$(PIP) install -r $(SRC_DIR)/tools/docwriter/requirements.txt
+	@echo "Running docwriter..."
+	python -B $(SRC_DIR)/tools/docwriter/docwriter.py \
+                  --prefix=ft2                          \
+                  --title=FreeType-$(version)           \
+                  --output=$(DOC_DIR)                   \
+                  $(PUBLIC_DIR)/*.h                     \
+                  $(PUBLIC_DIR)/config/*.h              \
+                  $(PUBLIC_DIR)/cache/*.h
+	@echo Building static site...
+	cd $(DOC_DIR) && mkdocs build
+	@echo Done.
+
 .PHONY: clean_project_std distclean_project_std
 
 # Standard cleaning and distclean rules.  These are not accepted

builds/os2/os2-def.mk

@@ -16,6 +16,7 @@
 DELETE    := del
 CAT       := type
 SEP       := $(strip \ )
+BIN       := Scripts
 BUILD_DIR := $(TOP_DIR)/builds/os2
 PLATFORM  := os2
 

builds/unix/unix-def.in

@@ -20,6 +20,7 @@ DELETE := rm -f
 DELDIR := rm -rf
 CAT    := cat
 SEP    := /
+BIN    := bin
 
 # this is used for `make distclean' and `make install'
 OBJ_BUILD ?= $(BUILD_DIR)

builds/unix/unixddef.mk

@@ -22,6 +22,7 @@ PLATFORM := unix
 DELETE := rm -f
 CAT    := cat
 SEP    := /
+BIN    := bin
 
 # we use a special devel ftoption.h
 DEVEL_DIR := $(TOP_DIR)/devel

builds/windows/win32-def.mk

@@ -16,6 +16,7 @@
 DELETE    := del
 CAT       := type
 SEP       := $(strip \ )
+BIN       := Scripts
 BUILD_DIR := $(TOP_DIR)/builds/windows
 PLATFORM  := windows