bgfx/examples/35-dynamic/dynamic.cpp

/*
 * Copyright 2011-2022 Branimir Karadzic. All rights reserved.
 * License: https://github.com/bkaradzic/bgfx/blob/master/LICENSE
 */

#include "common.h"
#include "bgfx_utils.h"
#include "imgui/imgui.h"

#include <bx/rng.h>

namespace
{

const uint32_t kDimWidth  = 11;
const uint32_t kDimHeight = 11;

struct PosColorVertex
{
	float m_x;
	float m_y;
	float m_z;
	uint32_t m_abgr;

	static void init()
	{
		ms_layout
			.begin()
			.add(bgfx::Attrib::Position, 3, bgfx::AttribType::Float)
			.add(bgfx::Attrib::Color0,   4, bgfx::AttribType::Uint8, true)
			.end();
	};

	static bgfx::VertexLayout ms_layout;
};

bgfx::VertexLayout PosColorVertex::ms_layout;

static PosColorVertex s_cubeVertices[] =
{
	{-1.0f,  1.0f,  1.0f, 0xff000000 },
	{ 1.0f,  1.0f,  1.0f, 0xff0000ff },
	{-1.0f, -1.0f,  1.0f, 0xff00ff00 },
	{ 1.0f, -1.0f,  1.0f, 0xff00ffff },
	{-1.0f,  1.0f, -1.0f, 0xffff0000 },
	{ 1.0f,  1.0f, -1.0f, 0xffff00ff },
	{-1.0f, -1.0f, -1.0f, 0xffffff00 },
	{ 1.0f, -1.0f, -1.0f, 0xffffffff },
};

static const uint16_t s_cubeTriList[] =
{
	0, 1, 2, // 0
	1, 3, 2,
	4, 6, 5, // 2
	5, 6, 7,
	0, 2, 4, // 4
	4, 2, 6,
	1, 5, 3, // 6
	5, 7, 3,
	0, 4, 1, // 8
	4, 5, 1,
	2, 3, 6, // 10
	6, 3, 7,
};

static const uint16_t s_cubeTriStrip[] =
{
	0, 1, 2,
	3,
	7,
	1,
	5,
	0,
	4,
	2,
	6,
	7,
	4,
	5,
};

class ExampleDynamic : public entry::AppI
{
public:
	ExampleDynamic(const char* _name, const char* _description, const char* _url)
		: entry::AppI(_name, _description, _url)
	{
	}

	void init(int32_t _argc, const char* const* _argv, uint32_t _width, uint32_t _height) override
	{
		BX_UNUSED(s_cubeTriList, s_cubeTriStrip);

		Args args(_argc, _argv);

		m_width  = _width;
		m_height = _height;
		m_debug  = BGFX_DEBUG_NONE;
		m_reset  = BGFX_RESET_VSYNC;

		bgfx::Init init;
		init.type     = args.m_type;
		init.vendorId = args.m_pciId;
		init.platformData.nwh  = entry::getNativeWindowHandle(entry::kDefaultWindowHandle);
		init.platformData.ndt  = entry::getNativeDisplayHandle();
		init.resolution.width  = m_width;
		init.resolution.height = m_height;
		init.resolution.reset  = m_reset;
		bgfx::init(init);

		// 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
				);

		// Create vertex stream declaration.
		PosColorVertex::init();

		// Create static vertex buffer.
		for (uint32_t yy = 0; yy < kDimHeight; ++yy)
		{
			for (uint32_t xx = 0; xx < kDimWidth; ++xx)
			{
				m_vbh[yy*kDimWidth+xx] = bgfx::createDynamicVertexBuffer(
					// Static data can be passed with bgfx::makeRef
					  bgfx::makeRef(s_cubeVertices, sizeof(s_cubeVertices) )
					, PosColorVertex::ms_layout
					);
			}
		}

		// Create static index buffer.
		m_ibh = bgfx::createDynamicIndexBuffer(
				// Static data can be passed with bgfx::makeRef
				bgfx::makeRef(s_cubeTriStrip, sizeof(s_cubeTriStrip) )
				);

		// Create program from shaders.
		m_program = loadProgram("vs_cubes", "fs_cubes");

		m_timeOffset = bx::getHPCounter();

		imguiCreate();
	}

	virtual int shutdown() override
	{
		imguiDestroy();

		// Cleanup.
		bgfx::destroy(m_ibh);
		for (uint32_t yy = 0; yy < kDimHeight; ++yy)
		{
			for (uint32_t xx = 0; xx < kDimWidth; ++xx)
			{
				bgfx::destroy(m_vbh[yy*kDimWidth+xx]);
			}
		}

		bgfx::destroy(m_program);

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

		return 0;
	}

	bool update() override
	{
		if (!entry::processEvents(m_width, m_height, m_debug, m_reset, &m_mouseState) )
		{
			imguiBeginFrame(m_mouseState.m_mx
				,  m_mouseState.m_my
				, (m_mouseState.m_buttons[entry::MouseButton::Left  ] ? IMGUI_MBUT_LEFT   : 0)
				| (m_mouseState.m_buttons[entry::MouseButton::Right ] ? IMGUI_MBUT_RIGHT  : 0)
				| (m_mouseState.m_buttons[entry::MouseButton::Middle] ? IMGUI_MBUT_MIDDLE : 0)
				,  m_mouseState.m_mz
				, uint16_t(m_width)
				, uint16_t(m_height)
				);

			showExampleDialog(this);

			imguiEndFrame();

			float time = (float)( (bx::getHPCounter()-m_timeOffset)/double(bx::getHPFrequency() ) );

			const bx::Vec3 at  = { 0.0f, 0.0f,   0.0f };
			const bx::Vec3 eye = { 0.0f, 0.0f, -35.0f };

			// Set view and projection matrix for view 0.
			{
				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::getCaps()->homogeneousDepth);
				bgfx::setViewTransform(0, view, proj);

				// 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);

			{
				float angle = bx::frnd(&m_mwc);
				float mtx[16];
				bx::mtxRotateZ(mtx, angle);

				const bgfx::Memory* mem = bgfx::copy(s_cubeVertices, sizeof(s_cubeVertices) );
				PosColorVertex* vertex = (PosColorVertex*)mem->data;
				const uint32_t abgr = m_mwc.gen();
				for (uint32_t ii = 0; ii < BX_COUNTOF(s_cubeVertices); ++ii)
				{
					bx::store(&vertex[ii].m_x, bx::mul(bx::load<bx::Vec3>(&s_cubeVertices[ii].m_x), mtx) );
					vertex[ii].m_abgr = abgr;
				}

				uint32_t idx = m_mwc.gen() % (kDimWidth*kDimHeight);
				bgfx::update(m_vbh[idx], 0, mem);
			}

			// Submit 11x11 cubes.
			for (uint32_t yy = 0; yy < kDimHeight; ++yy)
			{
				for (uint32_t xx = 0; xx < kDimWidth; ++xx)
				{
					float mtx[16];
					bx::mtxRotateXY(mtx, time + xx*0.21f, time + yy*0.37f);
					mtx[12] = -15.0f + float(xx)*3.0f;
					mtx[13] = -15.0f + float(yy)*3.0f;
					mtx[14] = 0.0f;

					// Set model matrix for rendering.
					bgfx::setTransform(mtx);

					// Set vertex and index buffer.
					bgfx::setVertexBuffer(0, m_vbh[yy*kDimWidth+xx]);
					bgfx::setIndexBuffer(m_ibh);

					// Set render states.
					bgfx::setState(0
						| BGFX_STATE_DEFAULT
						| BGFX_STATE_PT_TRISTRIP
						);

					// Submit primitive for rendering to view 0.
					bgfx::submit(0, m_program);
				}
			}

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

			return true;
		}

		return false;
	}

	entry::MouseState m_mouseState;

	bx::RngMwc m_mwc;
	uint32_t m_width;
	uint32_t m_height;
	uint32_t m_debug;
	uint32_t m_reset;
	bgfx::DynamicVertexBufferHandle m_vbh[kDimWidth*kDimHeight];
	bgfx::DynamicIndexBufferHandle m_ibh;
	bgfx::ProgramHandle m_program;
	int64_t m_timeOffset;
};

} // namespace

ENTRY_IMPLEMENT_MAIN(
	  ExampleDynamic
	, "35-dynamic"
	, "Dynamic buffers update."
	, "https://bkaradzic.github.io/bgfx/examples.html#dynamic"
	);