#! /bin/bash
#
#  This example displays each font in the /usr/share directory by
#  rendering it as an extruded font.  Iterate through the list with
#  '[' and ']' keys.
#
setglobal text = $1;
set -eu

source "$(BASH_SOURCE%/*)/../CmdlineGL.lib" || die "Can't find CmdlineGL.lib ($(BASH_SOURCE%/*)/../CmdlineGL.lib)";
CmdlineGL_LoadLib RenderLoop ModelViewer

setglobal fonts = ''( `find /usr/share -name '*.ttf' | grep -i mono` )
setglobal font_n = $(#fonts[@])
setglobal font_i = ''

proc swap_font {
	if [[ -n "$font_i" ]] { ftglDestroyFont font1; } else { setglobal font_i = '0'; true; }
	echo "$font_i/$font_n  $(fonts[font_i])"
	# Load font file and configure font rendering parameters
	ftglCreateExtrudeFont font1 $(fonts[font_i])
	ftglSetFontFaceSize   font1 72 72
	ftglSetFontDepth      font1 20
}

proc next_font {
	if sh-expr ' font_i + 1 < font_n ' {
		let ++font_i
		swap_font
	}
}
proc prev_font {
	if sh-expr ' font_i > 0 ' {
		let font_i--
		swap_font
	}
}

proc Init {
	# Initialize CmdlineGL for rendering only (no input or feedback)
	glEnable GL_NORMALIZE GL_DEPTH_TEST GL_CULL_FACE
	glShadeModel GL_SMOOTH

	# set up lighting (otherwise no change as it rotates)
	glEnable GL_LIGHTING GL_LIGHT0
	glLight GL_LIGHT0 GL_AMBIENT .8 .8 .8 0
	glLight GL_LIGHT0 GL_DIFFUSE 1 .8 .8 0
	glLight GL_LIGHT0 GL_SPECULAR .8 .8 .8 0
	glLight GL_LIGHT0 GL_POSITION 10 10 10 1
	swap_font
}

proc RenderLoop_Render {
	ModelViewer_Update
	
	glLoadIdentity
	ModelViewer_ApplyMatrix
	
	glTranslate -40 0 0
	glScale 1/40
	glColor 0.5 0.5 0.5 1
	ftglRenderFont font1 $(fonts[font_i]) FTGL_RENDER_ALL
	
	glFlush
	cglSwapBuffers
	glClear GL_COLOR_BUFFER_BIT GL_DEPTH_BUFFER_BIT
}

proc RenderLoop_DispatchEvent {
	if ! ModelViewer_DispatchEvent @Argv {
		if [[ "$1" == "K" && "$2" == "+" && "$3" == q ]] {
			setglobal RenderLoop_Done = '1'
		} elif [[ "$1" == "K" && "$2" == "+" && "$3" == ']' ]] {
			next_font
		} elif [[ "$1" == "K" && "$2" == "+" && "$3" == '[' ]] {
			prev_font
		} else {
			true
		}
	}
}

CmdlineGL_Start rw || die "Can't init CmdlineGL"
Init
RenderLoop_Run
cglQuit