/*
** Haaf's Game Engine 1.6
** Copyright (C) 2003-2007, Relish Games
** hge.relishgames.com
**
** hge_tut02 - Using input, sound and rendering
*/

#include "hge.h"

HGE *hge=0;

// Quad is the basic primitive in HGE
// used for rendering graphics.
// Quad contains 4 vertices, numbered
// 0 to 3 clockwise.
hgeQuad quad;

// Handle for a sound effect
HEFFECT snd;

// Some "gameplay" variables and constants
float x=100.0f, y=100.0f;
float dx=0.0f, dy=0.0f;

const float speed=90;
const float friction=0.98f;

// This function plays collision sound with
// parameters based on sprite position and speed
void boom() {
	int pan=int((x-400)/4);
	float pitch=(dx*dx+dy*dy)*0.0005f+0.2f;
	hge->Effect_PlayEx(snd,100,pan,pitch);
}

bool FrameFunc()
{
	// Get the time elapsed since last call of FrameFunc().
	// This will help us to synchronize on different
	// machines and video modes.
	float dt=hge->Timer_GetDelta();

	// Process keys
	if (hge->Input_GetKeyState(HGEK_ESCAPE)) return true;
	if (hge->Input_GetKeyState(HGEK_LEFT)) dx-=speed*dt;
	if (hge->Input_GetKeyState(HGEK_RIGHT)) dx+=speed*dt;
	if (hge->Input_GetKeyState(HGEK_UP)) dy-=speed*dt;
	if (hge->Input_GetKeyState(HGEK_DOWN)) dy+=speed*dt;

	// Do some movement calculations and collision detection	
	dx*=friction; dy*=friction; x+=dx; y+=dy;
	if(x>784) {x=784-(x-784);dx=-dx;boom();}
	if(x<16) {x=16+16-x;dx=-dx;boom();}
	if(y>584) {y=584-(y-584);dy=-dy;boom();}
	if(y<16) {y=16+16-y;dy=-dy;boom();}

	// Set up quad's screen coordinates
	quad.v[0].x=x-16; quad.v[0].y=y-16;
	quad.v[1].x=x+16; quad.v[1].y=y-16;
	quad.v[2].x=x+16; quad.v[2].y=y+16;
	quad.v[3].x=x-16; quad.v[3].y=y+16;

	// Continue execution
	return false;
}

// This function will be called by HGE when
// the application window should be redrawn.
// Put your rendering code here.
bool RenderFunc()
{
	// Begin rendering quads.
	// This function must be called
	// before any actual rendering.
	hge->Gfx_BeginScene();

	// Clear screen with black color
	hge->Gfx_Clear(0);

	// Render quads here. This time just
	// one of them will serve our needs.
	hge->Gfx_RenderQuad(&quad);

	// End rendering and update the screen
	hge->Gfx_EndScene();

	// RenderFunc should always return false
	return false;
}


int WINAPI WinMain(HINSTANCE, HINSTANCE, LPSTR, int)
{
	// Get HGE interface
	hge = hgeCreate(HGE_VERSION);

	// Set up log file, frame function, render function and window title
	hge->System_SetState(HGE_LOGFILE, "hge_tut02.log");
	hge->System_SetState(HGE_FRAMEFUNC, FrameFunc);
	hge->System_SetState(HGE_RENDERFUNC, RenderFunc);
	hge->System_SetState(HGE_TITLE, "HGE Tutorial 02 - Using input, sound and rendering");

	// Set up video mode
	hge->System_SetState(HGE_WINDOWED, true);
	hge->System_SetState(HGE_SCREENWIDTH, 800);
	hge->System_SetState(HGE_SCREENHEIGHT, 600);
	hge->System_SetState(HGE_SCREENBPP, 32);

	if(hge->System_Initiate())
	{
		// Load sound and texture
		snd=hge->Effect_Load("menu.wav");
		quad.tex=hge->Texture_Load("particles.png");
		if(!snd || !quad.tex)
		{
			// If one of the data files is not found, display
			// an error message and shutdown.
			MessageBox(NULL, "Can't load MENU.WAV or PARTICLES.PNG", "Error", MB_OK | MB_ICONERROR | MB_APPLMODAL);
			hge->System_Shutdown();
			hge->Release();
			return 0;
		}

		// Set up quad which we will use for rendering sprite
		quad.blend=BLEND_ALPHAADD | BLEND_COLORMUL | BLEND_ZWRITE;

		for(int i=0;i<4;i++)
		{
			// Set up z-coordinate of vertices
			quad.v[i].z=0.5f;
			// Set up color. The format of DWORD col is 0xAARRGGBB
			quad.v[i].col=0xFFFFA0FF;
		}

		// Set up quad's texture coordinates.
		// 0,0 means top left corner and 1,1 -
		// bottom right corner of the texture.
		quad.v[0].tx=96.0/128.0; quad.v[0].ty=64.0/128.0; 
		quad.v[1].tx=128.0/128.0; quad.v[1].ty=64.0/128.0; 
		quad.v[2].tx=128.0/128.0; quad.v[2].ty=96.0/128.0; 
		quad.v[3].tx=96.0/128.0; quad.v[3].ty=96.0/128.0; 

		// Let's rock now!
		hge->System_Start();

		// Free loaded texture and sound
		hge->Texture_Free(quad.tex);
		hge->Effect_Free(snd);
	}
	else MessageBox(NULL, hge->System_GetErrorMessage(), "Error", MB_OK | MB_ICONERROR | MB_SYSTEMMODAL);

	// Clean up and shutdown
	hge->System_Shutdown();
	hge->Release();
	return 0;
}
