/** 
 * @file llhudrender.cpp
 * @brief LLHUDRender class implementation
 *
 * $LicenseInfo:firstyear=2002&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 * 
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#include "llviewerprecompiledheaders.h"

#include "llhudrender.h"

#include "llrender.h"
#include "llgl.h"
#include "llviewercamera.h"
#include "v3math.h"
#include "llquaternion.h"
#include "llfontgl.h"
#include "llglheaders.h"
#include "llviewerwindow.h"
#include "llui.h"
#include "alglmath.h"

void hud_render_utf8text(const std::string &str, const LLVector3 &pos_agent,
					 const LLFontGL &font,
					 const U8 style,
					 const LLFontGL::ShadowType shadow,
					 const F32 x_offset, const F32 y_offset,
					 const LLColor4& color,
					 const BOOL orthographic)
{
	LLWString wstr(utf8str_to_wstring(str));
	hud_render_text(wstr, pos_agent, font, style, shadow, x_offset, y_offset, color, orthographic);
}

void hud_render_text(const LLWString &wstr, const LLVector3 &pos_agent,
					const LLFontGL &font,
					const U8 style,
					const LLFontGL::ShadowType shadow,
					const F32 x_offset, const F32 y_offset,
					const LLColor4& color,
					const BOOL orthographic)
{
	LLViewerCamera* camera = LLViewerCamera::getInstance();
	// Do cheap plane culling
	LLVector3 dir_vec = pos_agent - camera->getOrigin();
	dir_vec /= dir_vec.magVec();

	if (wstr.empty() || (!orthographic && dir_vec * camera->getAtAxis() <= 0.f))
	{
		return;
	}

	LLVector3 right_axis;
	LLVector3 up_axis;
	if (orthographic)
	{
		right_axis.setVec(0.f, -1.f / gViewerWindow->getWorldViewHeightScaled(), 0.f);
		up_axis.setVec(0.f, 0.f, 1.f / gViewerWindow->getWorldViewHeightScaled());
	}
	else
	{
		camera->getPixelVectors(pos_agent, up_axis, right_axis);
	}
	LLCoordFrame render_frame = *camera;
	LLQuaternion rot;
	if (!orthographic)
	{
		rot = render_frame.getQuaternion();
		rot = rot * LLQuaternion(-F_PI_BY_TWO, camera->getYAxis());
		rot = rot * LLQuaternion(F_PI_BY_TWO, camera->getXAxis());
	}
	else
	{
		rot = LLQuaternion(-F_PI_BY_TWO, LLVector3(0.f, 0.f, 1.f));
		rot = rot * LLQuaternion(-F_PI_BY_TWO, LLVector3(0.f, 1.f, 0.f));
	}
	F32 angle;
	LLVector3 axis;
	rot.getAngleAxis(&angle, axis);

	LLVector3 render_pos = pos_agent + (floorf(x_offset) * right_axis) + (floorf(y_offset) * up_axis);

	//get the render_pos in screen space
	LLMatrix4a modelview, projection;
	modelview.loadu(gGLModelView);
	projection.loadu(gGLProjection);

	LLVector3 window_coordinates;
	F32& winX = window_coordinates.mV[VX];
	F32& winY = window_coordinates.mV[VY];
	F32& winZ = window_coordinates.mV[VZ];

	const LLRect& world_view_rect = gViewerWindow->getWorldViewRectRaw();

	ALGLMath::projectf(render_pos, modelview, projection, world_view_rect, window_coordinates);
		
	//fonts all render orthographically, set up projection``
	gGL.matrixMode(LLRender::MM_PROJECTION);
	gGL.pushMatrix();
	gGL.matrixMode(LLRender::MM_MODELVIEW);
	gGL.pushMatrix();
	LLUI::pushMatrix();
		
	gl_state_for_2d(world_view_rect.getWidth(), world_view_rect.getHeight());
	gViewerWindow->setup3DViewport();
	
	winX -= world_view_rect.mLeft;
	winY -= world_view_rect.mBottom;
	LLUI::loadIdentity();
	gGL.loadIdentity();
	LLUI::translate((F32) winX*1.0f/LLFontGL::sScaleX, (F32) winY*1.0f/(LLFontGL::sScaleY), -(((F32) winZ*2.f)-1.f));
	F32 right_x;
	
	font.render(wstr, 0, 0, 1, color, LLFontGL::LEFT, LLFontGL::BASELINE, style, shadow, wstr.length(), 1000, &right_x);

	LLUI::popMatrix();
	gGL.popMatrix();

	gGL.matrixMode(LLRender::MM_PROJECTION);
	gGL.popMatrix();
	gGL.matrixMode(LLRender::MM_MODELVIEW);
}
