/*---------------------------------------------------------------------------------

	nehe lesson 1 port to GX by WinterMute

---------------------------------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <malloc.h>
#include <math.h>
#include <gccore.h>
#include <wiiuse/wpad.h>

#define DEFAULT_FIFO_SIZE	(256*1024)

static void *frameBuffer[2] = { NULL, NULL};
GXRModeObj *rmode;

//---------------------------------------------------------------------------------
int main( int argc, char **argv ){
//---------------------------------------------------------------------------------
	f32 yscale;

	u32 xfbHeight;

	Mtx	view;
	Mtx44 perspective;

	u32	fb = 0; 	// initial framebuffer index
	GXColor background = {0, 0, 0, 0xff};


	// init the vi.
	VIDEO_Init();
	WPAD_Init();

	rmode = VIDEO_GetPreferredMode(NULL);

	// allocate 2 framebuffers for double buffering
	frameBuffer[0] = MEM_K0_TO_K1(SYS_AllocateFramebuffer(rmode));
	frameBuffer[1] = MEM_K0_TO_K1(SYS_AllocateFramebuffer(rmode));

	VIDEO_Configure(rmode);
	VIDEO_SetNextFramebuffer(frameBuffer[fb]);
	VIDEO_SetBlack(FALSE);
	VIDEO_Flush();
	VIDEO_WaitVSync();
	if(rmode->viTVMode&VI_NON_INTERLACE) VIDEO_WaitVSync();

	// setup the fifo and then init the flipper
	void *gp_fifo = NULL;
	gp_fifo = memalign(32,DEFAULT_FIFO_SIZE);
	memset(gp_fifo,0,DEFAULT_FIFO_SIZE);

	GX_Init(gp_fifo,DEFAULT_FIFO_SIZE);

	// clears the bg to color and clears the z buffer
	GX_SetCopyClear(background, 0x00ffffff);

	// other gx setup
	GX_SetViewport(0,0,rmode->fbWidth,rmode->efbHeight,0,1);
	yscale = GX_GetYScaleFactor(rmode->efbHeight,rmode->xfbHeight);
	xfbHeight = GX_SetDispCopyYScale(yscale);
	GX_SetScissor(0,0,rmode->fbWidth,rmode->efbHeight);
	GX_SetDispCopySrc(0,0,rmode->fbWidth,rmode->efbHeight);
	GX_SetDispCopyDst(rmode->fbWidth,xfbHeight);
	GX_SetCopyFilter(rmode->aa,rmode->sample_pattern,GX_TRUE,rmode->vfilter);
	GX_SetFieldMode(rmode->field_rendering,((rmode->viHeight==2*rmode->xfbHeight)?GX_ENABLE:GX_DISABLE));

	GX_SetCullMode(GX_CULL_NONE);
	GX_CopyDisp(frameBuffer[fb],GX_TRUE);
	GX_SetDispCopyGamma(GX_GM_1_0);

	// setup our camera at the origin
	// looking down the -z axis with y up
	guVector cam = {0.0F, 0.0F, 0.0F},
			up = {0.0F, 1.0F, 0.0F},
		  look = {0.0F, 0.0F, -1.0F};
	guLookAt(view, &cam, &up, &look);


	// setup our projection matrix
	// this creates a perspective matrix with a view angle of 90,
	// and aspect ratio based on the display resolution
	f32 w = rmode->viWidth;
	f32 h = rmode->viHeight;
	guPerspective(perspective, 45, (f32)w/h, 0.1F, 300.0F);
	GX_LoadProjectionMtx(perspective, GX_PERSPECTIVE);

	while(1) {

		WPAD_ScanPads();

		if (WPAD_ButtonsDown(0) & WPAD_BUTTON_HOME) exit(0);

		// do this before drawing
		GX_SetViewport(0,0,rmode->fbWidth,rmode->efbHeight,0,1);


		// do this stuff after drawing
		GX_DrawDone();

		fb ^= 1;		// flip framebuffer
		GX_SetZMode(GX_TRUE, GX_LEQUAL, GX_TRUE);
		GX_SetColorUpdate(GX_TRUE);
		GX_CopyDisp(frameBuffer[fb],GX_TRUE);

		VIDEO_SetNextFramebuffer(frameBuffer[fb]);

		VIDEO_Flush();

		VIDEO_WaitVSync();


	}
	return 0;
}

