#include "precompiled.h"

#include "Matrix3D.h"
#include "Renderer.h"
#include "Terrain.h"
#include "LightEnv.h"
#include "TextureManager.h"
#include "ObjectManager.h"
#include "Prometheus.h"

#include "sdl.h"
#include "res/tex.h"
#include "detect.h"

void InitScene ();
void InitResources ();
void RenderScene ();

extern bool keys[512];	// SDL also defines non-ascii keys; 512 should be enough
extern bool mouseButtons[5];

CMatrix3D			g_WorldMat;
CTerrain			g_Terrain;
CCamera				g_Camera;
CLightEnv			g_LightEnv;

int					SelPX, SelPY, SelTX, SelTY;
int					g_BaseTexCounter = 0;
int					g_SecTexCounter = 1;
int					g_TransTexCounter = 0;

int					g_TickCounter = 0;
double				g_LastTime;

float g_CameraZoom = 10;

const int NUM_ALPHA_MAPS = 13;
const float ViewScrollSpeed = 60;
const float ViewRotateSensitivity = 0.002f;
const float ViewDragSensitivity = 0.5f;
const float ViewZoomSensitivityWheel = 16.0f;
const float ViewZoomSensitivityKey = 256.0f;
const float ViewZoomSmoothness = 0.02f; // 0.0 = instantaneous zooming, 1.0 = so slow it never moves
float ViewFOV;

int mouse_x=50, mouse_y=50;

extern int g_xres, g_yres;

void terr_init()
{
	SViewPort vp;
	vp.m_X=0;
	vp.m_Y=0;
	vp.m_Width=g_xres;
	vp.m_Height=g_yres;
	g_Camera.SetViewPort(&vp);

	InitResources ();
	InitScene ();
}

void terr_update(const float DeltaTime)
{

#define CAMERASTYLE 2 // 0 = old style, 1 = relatively new style, 2 = newer style

#if CAMERASTYLE == 2


	// Calculate mouse movement
	static int mouse_last_x = 0;
	static int mouse_last_y = 0;
	int mouse_dx = mouse_x - mouse_last_x;
	int mouse_dy = mouse_y - mouse_last_y;
	mouse_last_x = mouse_x;
	mouse_last_y = mouse_y;

	// Miscellaneous vectors
	CVector3D forwards = g_Camera.m_Orientation.GetIn();
	CVector3D upwards (0.0f, 1.0f, 0.0f);
	CVector3D rightwards = upwards.Cross(forwards);
	rightwards.Normalize();
	
	CVector3D forwards_horizontal = forwards;
	forwards_horizontal.Y = 0.0f;
	forwards_horizontal.Normalize();

	if (mouseButtons[SDL_BUTTON_MIDDLE])
	{
		if (keys[SDLK_LCTRL] || keys[SDLK_RCTRL])
		{
			// Ctrl + middle-drag to rotate view

			// Untranslate the camera, so it rotates around the correct point
			CVector3D position = g_Camera.m_Orientation.GetTranslation();
			g_Camera.m_Orientation.Translate(position*-1);

			// Sideways rotation
			g_Camera.m_Orientation.RotateY(ViewRotateSensitivity * (float)(mouse_dx));

			// Up/down rotation
			CQuaternion temp;
			temp.FromAxisAngle(rightwards, ViewRotateSensitivity * (float)(mouse_dy));
			g_Camera.m_Orientation.Rotate(temp);

			// Retranslate back to the right position
			g_Camera.m_Orientation.Translate(position);

		}
		else
		{
			// Middle-drag to pan

			g_Camera.m_Orientation.Translate(rightwards * (ViewDragSensitivity * mouse_dx));
			g_Camera.m_Orientation.Translate(forwards_horizontal * (-ViewDragSensitivity * mouse_dy));
		}
	}

	// Mouse movement

	if (mouse_x >= g_xres-2)
		g_Camera.m_Orientation.Translate(rightwards * (ViewScrollSpeed * DeltaTime));
	else if (mouse_x <= 3)
		g_Camera.m_Orientation.Translate(-rightwards * (ViewScrollSpeed * DeltaTime));

	if (mouse_y >= g_yres-2)
		g_Camera.m_Orientation.Translate(-forwards_horizontal * (ViewScrollSpeed * DeltaTime));
	else if (mouse_y <= 3)
		g_Camera.m_Orientation.Translate(forwards_horizontal * (ViewScrollSpeed * DeltaTime));


	// Keyboard movement (added to mouse movement, so you can go faster if you want)

	if (keys[SDLK_RIGHT])
		g_Camera.m_Orientation.Translate(rightwards * (ViewScrollSpeed * DeltaTime));
	if (keys[SDLK_LEFT])
		g_Camera.m_Orientation.Translate(-rightwards * (ViewScrollSpeed * DeltaTime));

	if (keys[SDLK_DOWN])
		g_Camera.m_Orientation.Translate(-forwards_horizontal * (ViewScrollSpeed * DeltaTime));
	if (keys[SDLK_UP])
		g_Camera.m_Orientation.Translate(forwards_horizontal * (ViewScrollSpeed * DeltaTime));


	// Smoothed zooming (move a certain percentage towards the desired zoom distance every frame)

	static float zoom_delta = 0.0f;

	if (mouseButtons[SDL_BUTTON_WHEELUP])
		zoom_delta -= ViewZoomSensitivityWheel;
	else if (mouseButtons[SDL_BUTTON_WHEELDOWN])
		zoom_delta += ViewZoomSensitivityWheel;

	if (keys[SDLK_MINUS])
		zoom_delta -= ViewZoomSensitivityKey*DeltaTime;
	else if (keys[SDLK_EQUALS])
		zoom_delta += ViewZoomSensitivityKey*DeltaTime;

	if (zoom_delta)
	{
		float zoom_proportion = powf(ViewZoomSmoothness, DeltaTime);
		g_Camera.m_Orientation.Translate(forwards * (zoom_delta * (1.0f-zoom_proportion)));
		zoom_delta *= zoom_proportion;
	}


#elif CAMERASTYLE == 1

	// Remember previous mouse position, to calculate changes
	static mouse_last_x = 0;
	static mouse_last_y = 0;

	// Miscellaneous vectors
	CVector3D forwards = g_Camera.m_Orientation.GetIn();
	CVector3D upwards (0.0f, 1.0f, 0.0f);
	CVector3D rightwards = upwards.Cross(forwards);

	// Click and drag to look around
	if (mouseButtons[0])
	{
		// Untranslate the camera, so it rotates around the correct point
		CVector3D position = g_Camera.m_Orientation.GetTranslation();
		g_Camera.m_Orientation.Translate(position*-1);

		// Sideways rotation
		g_Camera.m_Orientation.RotateY(ViewRotateSpeed*(float)(mouse_x-mouse_last_x));

		// Up/down rotation
		CQuaternion temp;
		temp.FromAxisAngle(rightwards, ViewRotateSpeed*(float)(mouse_y-mouse_last_y));
		g_Camera.m_Orientation.Rotate(temp);

		// Retranslate back to the right position
		g_Camera.m_Orientation.Translate(position);
	}
	mouse_last_x = mouse_x;
	mouse_last_y = mouse_y;

	// Calculate the necessary vectors for movement

	rightwards.Normalize();
	CVector3D forwards_horizontal = upwards.Cross(rightwards);
	forwards_horizontal.Normalize();

	// Move when desirable

	if (mouse_x >= g_xres-2)
		g_Camera.m_Orientation.Translate(rightwards);
	else if (mouse_x <= 3)
		g_Camera.m_Orientation.Translate(-rightwards);

	if (mouse_y >= g_yres-2)
		g_Camera.m_Orientation.Translate(forwards_horizontal);
	else if (mouse_y <= 3)
		g_Camera.m_Orientation.Translate(-forwards_horizontal);

	// Smoothed height-changing (move a certain percentage towards the desired height every frame)

	static float height_delta = 0.0f;

	if (mouseButtons[SDL_BUTTON_WHEELUP])
		height_delta -= 4.0f;
	else if (mouseButtons[SDL_BUTTON_WHEELDOWN])
		height_delta += 4.0f;

	const float height_speed = 0.2f;
	g_Camera.m_Orientation.Translate(0.0f, height_delta*height_speed, 0.0f);
	height_delta *= (1.0f - height_speed);

#else // CAMERASTYLE == 0

	const float dx = ViewScrollSpeed * DeltaTime;
	const CVector3D Right(dx,0, dx);
	const CVector3D Up   (dx,0,-dx);

	if (mouse_x >= g_xres-2)
		g_Camera.m_Orientation.Translate(Right);
	if (mouse_x <= 3)
		g_Camera.m_Orientation.Translate(Right*-1);

	if (mouse_y >= g_yres-2)
		g_Camera.m_Orientation.Translate(Up);
	if (mouse_y <= 3)
		g_Camera.m_Orientation.Translate(Up*-1);

	/*
	janwas: grr, plotted the zoom vector on paper twice, but it appears
	to be completely wrong. sticking with the FOV hack for now.
	if anyone sees what's wrong, or knows how to correctly implement zoom,
	please put this code out of its misery :)
	*/
	// RC - added ScEd style zoom in and out (actually moving camera, rather than fudging fov)	

	float dir=0;
	if (mouseButtons[SDL_BUTTON_WHEELUP]) dir=-1;
	else if (mouseButtons[SDL_BUTTON_WHEELDOWN]) dir=1;	

	float factor=dir*dir;
	if (factor) {
		if (dir<0) factor=-factor;
		CVector3D forward=g_Camera.m_Orientation.GetIn();

		// check we're not going to zoom into the terrain, or too far out into space
		float h=g_Camera.m_Orientation.GetTranslation().Y+forward.Y*factor*g_CameraZoom;
		float minh=65536*HEIGHT_SCALE*1.05f;
		
		if (h<minh || h>1500) {
			// yup, we will; don't move anywhere (do clamped move instead, at some point)
		} else {
			// do a full move
			g_CameraZoom-=(factor)*0.1f;
			if (g_CameraZoom<0.01f) g_CameraZoom=0.01f;
			g_Camera.m_Orientation.Translate(forward*(factor*g_CameraZoom));
		}
	}
#endif // CAMERASTYLE

	g_Camera.UpdateFrustum ();
}






bool terr_handler(const SDL_Event& ev)
{
	switch(ev.type)
	{
	case SDL_MOUSEMOTION:
		mouse_x = ev.motion.x;
		mouse_y = ev.motion.y;
		break;
	

	case SDL_KEYDOWN:
		switch(ev.key.keysym.sym)
		{
		case 'W':
			if (g_Renderer.GetTerrainRenderMode()==WIREFRAME) {
				g_Renderer.SetTerrainRenderMode(SOLID);
			} else {
				g_Renderer.SetTerrainRenderMode(WIREFRAME);
			}
			break;

		case 'H':
			// quick hack to return camera home, for screenshots (after alt+tabbing)
			g_Camera.SetProjection (1, 5000, DEGTORAD(20));
			g_Camera.m_Orientation.SetXRotation(DEGTORAD(30));
			g_Camera.m_Orientation.RotateY(DEGTORAD(-45));
			g_Camera.m_Orientation.Translate (100, 150, -100);
			break;

		}
	}

	return false;
}




void InitScene ()
{
	// setup default lighting environment
	g_LightEnv.m_SunColor=RGBColor(1,1,1);
	g_LightEnv.m_Rotation=DEGTORAD(270);
	g_LightEnv.m_Elevation=DEGTORAD(45);
	g_LightEnv.m_TerrainAmbientColor=RGBColor(0,0,0);
	g_LightEnv.m_UnitsAmbientColor=RGBColor(0.4f,0.4f,0.4f);
	g_Renderer.SetLightEnv(&g_LightEnv);

	// load terrain
	Handle ht = tex_load("terrain.raw");
	if(ht > 0)
	{
		const u8* p;
		int w;
		int h;

		tex_info(ht, &w, &h, NULL, NULL, (void **)&p);

		printf("terrain.raw: %dx%d\n", w, h);

		u16 *p16=new u16[w*h];
		u16 *p16p=p16;
		while (p16p < p16+(w*h))
			*p16p++ = (*p++) << 8;

		g_Terrain.Resize(w/PATCH_SIZE);
		g_Terrain.SetHeightMap(p16);

		delete[] p16;
		
		tex_free(ht);
	}

	// get default texture to apply to terrain
	CTextureEntry* texture=0;
	for (uint ii=0;ii<g_TexMan.m_TerrainTextures.size();ii++) {  
		if (g_TexMan.m_TerrainTextures[ii].m_Textures.size()) {
			texture=g_TexMan.m_TerrainTextures[ii].m_Textures[0];
			break;
		}
	}


	// cover entire terrain with default texture
	u32 patchesPerSide=g_Terrain.GetPatchesPerSide();
	for (uint pj=0; pj<patchesPerSide; pj++) {
		for (uint pi=0; pi<patchesPerSide; pi++) {
			
			CPatch* patch=g_Terrain.GetPatch(pi,pj);
			
			for (int j=0;j<PATCH_SIZE;j++) {
				for (int i=0;i<PATCH_SIZE;i++) {
					patch->m_MiniPatches[j][i].Tex1=texture ? texture->GetHandle() :0;
				}
			}
		}
	}

	g_Camera.SetProjection (1, 5000, DEGTORAD(20));
	g_Camera.m_Orientation.SetXRotation(DEGTORAD(30));
	g_Camera.m_Orientation.RotateY(DEGTORAD(-45));

	g_Camera.m_Orientation.Translate (100, 150, -100);

}

void InitResources()
{
	g_TexMan.LoadTerrainTextures();
	g_ObjMan.LoadObjects();

	const char* fns[CRenderer::NumAlphaMaps] = {
		"art/textures/terrain/alphamaps/special/blendcircle.png",
		"art/textures/terrain/alphamaps/special/blendlshape.png",
		"art/textures/terrain/alphamaps/special/blendedge.png",
		"art/textures/terrain/alphamaps/special/blendedgecorner.png",
		"art/textures/terrain/alphamaps/special/blendedgetwocorners.png",
		"art/textures/terrain/alphamaps/special/blendfourcorners.png",
		"art/textures/terrain/alphamaps/special/blendtwooppositecorners.png",
		"art/textures/terrain/alphamaps/special/blendlshapecorner.png",
		"art/textures/terrain/alphamaps/special/blendtwocorners.png",
		"art/textures/terrain/alphamaps/special/blendcorner.png",
		"art/textures/terrain/alphamaps/special/blendtwoedges.png",
		"art/textures/terrain/alphamaps/special/blendthreecorners.png",
		"art/textures/terrain/alphamaps/special/blendushape.png",
		"art/textures/terrain/alphamaps/special/blendbad.png"
	};

	g_Renderer.LoadAlphaMaps(fns);
}