/*
 * Copyright 2011-2016 Branimir Karadzic. All rights reserved.
 * License: https://github.com/bkaradzic/bgfx#license-bsd-2-clause
 */

#include "common.h"
#include "bgfx_utils.h"

class ExampleMesh : public entry::AppI
{
	void init(int _argc, char** _argv) BX_OVERRIDE
	{
		Args args(_argc, _argv);

		m_width  = 1280;
		m_height = 720;
		m_debug  = BGFX_DEBUG_TEXT;
		m_reset  = BGFX_RESET_VSYNC;

		bgfx::init(args.m_type, args.m_pciId);
		bgfx::reset(m_width, m_height, m_reset);

		// Enable debug text.
		bgfx::setDebug(m_debug);

		// Set view 0 clear state.
		bgfx::setViewClear(0
				, BGFX_CLEAR_COLOR|BGFX_CLEAR_DEPTH
				, 0x303030ff
				, 1.0f
				, 0
				);

		u_time = bgfx::createUniform("u_time", bgfx::UniformType::Vec4);

		// Create program from shaders.
		m_program = loadProgram("vs_mesh", "fs_mesh");

		m_mesh = meshLoad("meshes/bunny.bin");

		m_timeOffset = bx::getHPCounter();
	}

	int shutdown() BX_OVERRIDE
	{
		meshUnload(m_mesh);

		// Cleanup.
		bgfx::destroyProgram(m_program);

		bgfx::destroyUniform(u_time);

		// Shutdown bgfx.
		bgfx::shutdown();

		return 0;
	}

	bool update() BX_OVERRIDE
	{
		if (!entry::processEvents(m_width, m_height, m_debug, m_reset) )
		{
			// Set view 0 default viewport.
			bgfx::setViewRect(0, 0, 0, uint16_t(m_width), uint16_t(m_height) );

			// This dummy draw call is here to make sure that view 0 is cleared
			// if no other draw calls are submitted to view 0.
			bgfx::touch(0);

			int64_t now = bx::getHPCounter();
			static int64_t last = now;
			const int64_t frameTime = now - last;
			last = now;
			const double freq = double(bx::getHPFrequency() );
			const double toMs = 1000.0/freq;
			float time = (float)( (bx::getHPCounter()-m_timeOffset)/double(bx::getHPFrequency() ) );
			bgfx::setUniform(u_time, &time);

			// Use debug font to print information about this example.
			bgfx::dbgTextClear();
			bgfx::dbgTextPrintf(0, 1, 0x4f, "bgfx/examples/04-mesh");
			bgfx::dbgTextPrintf(0, 2, 0x6f, "Description: Loading meshes.");
			bgfx::dbgTextPrintf(0, 3, 0x0f, "Frame: % 7.3f[ms]", double(frameTime)*toMs);

			float at[3]  = { 0.0f, 1.0f,  0.0f };
			float eye[3] = { 0.0f, 1.0f, -2.5f };

			// Set view and projection matrix for view 0.
			const bgfx::HMD* hmd = bgfx::getHMD();
			if (NULL != hmd && 0 != (hmd->flags & BGFX_HMD_RENDERING) )
			{
				float view[16];
				bx::mtxQuatTranslationHMD(view, hmd->eye[0].rotation, eye);
				bgfx::setViewTransform(0, view, hmd->eye[0].projection, BGFX_VIEW_STEREO, hmd->eye[1].projection);

				// Set view 0 default viewport.
				//
				// Use HMD's width/height since HMD's internal frame buffer size
				// might be much larger than window size.
				bgfx::setViewRect(0, 0, 0, hmd->width, hmd->height);
			}
			else
			{
				float view[16];
				bx::mtxLookAt(view, eye, at);

				float proj[16];
				bx::mtxProj(proj, 60.0f, float(m_width)/float(m_height), 0.1f, 100.0f);
				bgfx::setViewTransform(0, view, proj);

				// Set view 0 default viewport.
				bgfx::setViewRect(0, 0, 0, uint16_t(m_width), uint16_t(m_height) );
			}

			float mtx[16];
			bx::mtxRotateXY(mtx
				, 0.0f
				, time*0.37f
				);

			meshSubmit(m_mesh, 0, m_program, mtx);

			// Advance to next frame. Rendering thread will be kicked to
			// process submitted rendering primitives.
			bgfx::frame();

			return true;
		}

		return false;
	}

	uint32_t m_width;
	uint32_t m_height;
	uint32_t m_debug;
	uint32_t m_reset;

	int64_t m_timeOffset;
	Mesh* m_mesh;
	bgfx::ProgramHandle m_program;
	bgfx::UniformHandle u_time;
};

ENTRY_IMPLEMENT_MAIN(ExampleMesh);