Cleanup.

examples/27-terrain/fs_terrain.sc

@@ -9,5 +9,5 @@ $input v_position, v_texcoord0
 
 void main()
 {
-    gl_FragColor = vec4(v_texcoord0.x, v_texcoord0.y, v_position.y / 50.0, 1.0); 
+	gl_FragColor = vec4(v_texcoord0.x, v_texcoord0.y, v_position.y / 50.0, 1.0);
 }

examples/27-terrain/terrain.cpp

@@ -17,470 +17,506 @@ static uint32_t s_terrainSize = 256;
 
 struct PosTexCoord0Vertex
 {
-   float m_x;
-   float m_y;
-   float m_z;
-   float m_u;
-   float m_v;
-
-   static void init()
-   {
-      ms_decl
-         .begin()
-         .add(bgfx::Attrib::Position, 3, bgfx::AttribType::Float)
-         .add(bgfx::Attrib::TexCoord0, 2, bgfx::AttribType::Float)
-         .end();
-   }
-
-   static bgfx::VertexDecl ms_decl;
+	float m_x;
+	float m_y;
+	float m_z;
+	float m_u;
+	float m_v;
+
+	static void init()
+	{
+		ms_decl
+			.begin()
+			.add(bgfx::Attrib::Position, 3, bgfx::AttribType::Float)
+			.add(bgfx::Attrib::TexCoord0, 2, bgfx::AttribType::Float)
+			.end();
+	}
+
+	static bgfx::VertexDecl ms_decl;
 };
 
 bgfx::VertexDecl PosTexCoord0Vertex::ms_decl;
 
 struct TerrainData
 {
-   uint32_t             m_mode;
-   bool                 m_dirty;
-   float                m_transform[16];
-   uint8_t*             m_heightMap;
-
-   PosTexCoord0Vertex*  m_vertices;
-   uint32_t             m_vertexCount;
-   uint16_t*            m_indices;
-   uint32_t             m_indexCount;
+	uint32_t             m_mode;
+	bool                 m_dirty;
+	float                m_transform[16];
+	uint8_t*             m_heightMap;
+
+	PosTexCoord0Vertex*  m_vertices;
+	uint32_t             m_vertexCount;
+	uint16_t*            m_indices;
+	uint32_t             m_indexCount;
 };
 
 struct BrushData
 {
-   bool    m_raise;
-   int32_t m_size;
-   float   m_power;
+	bool    m_raise;
+	int32_t m_size;
+	float   m_power;
 };
 
 class Terrain : 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(bgfx::RendererType::Direct3D11, args.m_pciId);
-      bgfx::reset(m_width, m_height, m_reset);
-
-      // Enable m_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.
-      PosTexCoord0Vertex::init();
-
-      // Create program from shaders.
-      m_terrainProgram              = loadProgram("vs_terrain",                "fs_terrain");
-      m_terrainHeightTextureProgram = loadProgram("vs_terrain_height_texture", "fs_terrain");
-
-      // Imgui.
-      imguiCreate();
-
-      m_timeOffset = bx::getHPCounter();
-      const bgfx::RendererType::Enum renderer = bgfx::getRendererType();
-      s_texelHalf = bgfx::RendererType::Direct3D9 == renderer ? 0.5f : 0.0f;
-      s_originBottomLeft = bgfx::RendererType::OpenGL == renderer || bgfx::RendererType::OpenGLES == renderer;
-
-      m_vbh.idx = bgfx::invalidHandle;
-      m_ibh.idx = bgfx::invalidHandle;
-      m_dvbh.idx = bgfx::invalidHandle;
-      m_dibh.idx = bgfx::invalidHandle;
-      m_heightTexture.idx = bgfx::invalidHandle;
-      s_heightTexture = bgfx::createUniform("s_heightTexture", bgfx::UniformType::Int1);
-
-      m_oldWidth  = 0;
-      m_oldHeight = 0;
-      m_oldReset  = m_reset;
-
-      m_scrollArea   = 0;
-
-      m_brush.m_power = 0.5f;
-      m_brush.m_size  = 10;
-      m_brush.m_raise = true;
+	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(bgfx::RendererType::Direct3D11, args.m_pciId);
+		bgfx::reset(m_width, m_height, m_reset);
+
+		// Enable m_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.
+		PosTexCoord0Vertex::init();
+
+		// Create program from shaders.
+		m_terrainProgram              = loadProgram("vs_terrain",                "fs_terrain");
+		m_terrainHeightTextureProgram = loadProgram("vs_terrain_height_texture", "fs_terrain");
+
+		// Imgui.
+		imguiCreate();
+
+		m_timeOffset = bx::getHPCounter();
+		const bgfx::RendererType::Enum renderer = bgfx::getRendererType();
+		s_texelHalf = bgfx::RendererType::Direct3D9 == renderer ? 0.5f : 0.0f;
+		s_originBottomLeft = bgfx::RendererType::OpenGL == renderer || bgfx::RendererType::OpenGLES == renderer;
+
+		m_vbh.idx = bgfx::invalidHandle;
+		m_ibh.idx = bgfx::invalidHandle;
+		m_dvbh.idx = bgfx::invalidHandle;
+		m_dibh.idx = bgfx::invalidHandle;
+		m_heightTexture.idx = bgfx::invalidHandle;
+		s_heightTexture = bgfx::createUniform("s_heightTexture", bgfx::UniformType::Int1);
+
+		m_oldWidth  = 0;
+		m_oldHeight = 0;
+		m_oldReset  = m_reset;
+
+		m_scrollArea   = 0;
+
+		m_brush.m_power = 0.5f;
+		m_brush.m_size  = 10;
+		m_brush.m_raise = true;
 
 		m_terrain.m_mode     = 0;
-      m_terrain.m_dirty     = true;
-      m_terrain.m_vertices  = new PosTexCoord0Vertex[s_terrainSize * s_terrainSize];
-      m_terrain.m_indices   = new uint16_t[s_terrainSize * s_terrainSize * 6];
-      m_terrain.m_heightMap = new uint8_t[s_terrainSize * s_terrainSize];
-
-      bx::mtxSRT(m_terrain.m_transform, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f);
-      memset(m_terrain.m_heightMap, 0, sizeof(uint8_t) * s_terrainSize * s_terrainSize);
-
-      cameraCreate();
-
-      const float initialPos[3] = { 0.0f, 15.0f, 0.0f };
-      cameraSetPosition(initialPos);
-      cameraSetVerticalAngle(0.0f);
-   }
-
-   virtual int shutdown() BX_OVERRIDE
-   {
-      // Cleanup.
-      cameraDestroy();
-      imguiDestroy();
-
-      if (bgfx::isValid(m_ibh))
-		   bgfx::destroyIndexBuffer(m_ibh);
-      if (bgfx::isValid(m_vbh))
-		   bgfx::destroyVertexBuffer(m_vbh);
-
-      if (bgfx::isValid(m_dibh))
-         bgfx::destroyDynamicIndexBuffer(m_dibh);
-      if (bgfx::isValid(m_dvbh))
-         bgfx::destroyDynamicVertexBuffer(m_dvbh);
-
-      bgfx::destroyUniform(s_heightTexture);
-      if (bgfx::isValid(m_heightTexture))
-         bgfx::destroyTexture(m_heightTexture);
-
-      bgfx::destroyProgram(m_terrainProgram);
-      bgfx::destroyProgram(m_terrainHeightTextureProgram);
-
-      delete[] m_terrain.m_vertices;
-      delete[] m_terrain.m_indices;
-      delete[] m_terrain.m_heightMap;
-
-      // Shutdown bgfx.
-      bgfx::shutdown();
-
-      return 0;
-   }
-
-   void updateTerrainMesh()
-   {
-      m_terrain.m_vertexCount = 0;
-      for (uint32_t y = 0; y < s_terrainSize; y++)
-      {
-         for (uint32_t x = 0; x < s_terrainSize; x++)
-         {
-            PosTexCoord0Vertex* vert = &m_terrain.m_vertices[m_terrain.m_vertexCount];
-            vert->m_x = (float)x;
-            vert->m_y = m_terrain.m_heightMap[(y * s_terrainSize) + x];
-            vert->m_z = (float)y;
-            vert->m_u = (float)x / (float)s_terrainSize;
-            vert->m_v = (float)y / (float)s_terrainSize;
-
-            m_terrain.m_vertexCount++;
-         }
-      }
-
-      m_terrain.m_indexCount = 0;
-      for (uint32_t y = 0; y < (s_terrainSize - 1); y++)
-      {
-         uint32_t y_offset = (y * s_terrainSize);
-         for (uint32_t x = 0; x < (s_terrainSize - 1); x++)
-         {
-            m_terrain.m_indices[m_terrain.m_indexCount] = y_offset + x + 1;
-            m_terrain.m_indices[m_terrain.m_indexCount + 1] = y_offset + x + s_terrainSize;
-            m_terrain.m_indices[m_terrain.m_indexCount + 2] = y_offset + x;
-            m_terrain.m_indices[m_terrain.m_indexCount + 3] = y_offset + x + s_terrainSize + 1;
-            m_terrain.m_indices[m_terrain.m_indexCount + 4] = y_offset + x + s_terrainSize;
-            m_terrain.m_indices[m_terrain.m_indexCount + 5] = y_offset + x + 1;
-
-            m_terrain.m_indexCount += 6;
-         }
-      }
-   }
-
-   void updateTerrain()
-   {
-      const bgfx::Memory* mem;
-
-      // Vertex Buffer : Destroy and recreate a regular vertex buffer to update terrain.
-      if (m_terrain.m_mode == 0)
-      {
-         updateTerrainMesh();
-
-         if (bgfx::isValid(m_vbh))
-            bgfx::destroyVertexBuffer(m_vbh);
-
-         mem = bgfx::makeRef(&m_terrain.m_vertices[0], sizeof(PosTexCoord0Vertex) * m_terrain.m_vertexCount);
-         m_vbh = bgfx::createVertexBuffer(mem, PosTexCoord0Vertex::ms_decl);
-
-         if (bgfx::isValid(m_ibh))
-            bgfx::destroyIndexBuffer(m_ibh);
-
-         mem = bgfx::makeRef(&m_terrain.m_indices[0], sizeof(uint16_t) * m_terrain.m_indexCount);
-         m_ibh = bgfx::createIndexBuffer(mem);
-      }
-
-      // Dynamic Vertex Buffer : Utilize dynamic vertex buffer to update terrain.
-      if (m_terrain.m_mode == 1)
-      {
-         updateTerrainMesh();
-
-         if (!bgfx::isValid(m_dvbh))
-            m_dvbh = bgfx::createDynamicVertexBuffer(m_terrain.m_vertexCount, PosTexCoord0Vertex::ms_decl);
-
-         mem = bgfx::makeRef(&m_terrain.m_vertices[0], sizeof(PosTexCoord0Vertex) * m_terrain.m_vertexCount);
-         bgfx::updateDynamicVertexBuffer(m_dvbh, 0, mem);
-
-         if (!bgfx::isValid(m_dibh))
-            m_dibh = bgfx::createDynamicIndexBuffer(m_terrain.m_indexCount);
-
-         mem = bgfx::makeRef(&m_terrain.m_indices[0], sizeof(uint16_t) * m_terrain.m_indexCount);
-         bgfx::updateDynamicIndexBuffer(m_dibh, 0, mem);
-      }
-
-      // Height Texture: Update a height texture that is sampled in the terrain vertex shader.
-      if (m_terrain.m_mode == 2)
-      {
-         if (!bgfx::isValid(m_vbh) || !bgfx::isValid(m_ibh))
-         {
-            updateTerrainMesh();
-
-            mem = bgfx::makeRef(&m_terrain.m_vertices[0], sizeof(PosTexCoord0Vertex) * m_terrain.m_vertexCount);
-            m_vbh = bgfx::createVertexBuffer(mem, PosTexCoord0Vertex::ms_decl);
-
-            mem = bgfx::makeRef(&m_terrain.m_indices[0], sizeof(uint16_t) * m_terrain.m_indexCount);
-            m_ibh = bgfx::createIndexBuffer(mem);
-         }
-
-         if (!bgfx::isValid(m_heightTexture))
-            m_heightTexture = bgfx::createTexture2D(s_terrainSize, s_terrainSize, 1, bgfx::TextureFormat::R8);
-
-         mem = bgfx::makeRef(&m_terrain.m_heightMap[0], sizeof(uint8_t) * s_terrainSize * s_terrainSize);
-         bgfx::updateTexture2D(m_heightTexture, 0, 0, 0, s_terrainSize, s_terrainSize, mem);
-      }
-   }
-
-   void paintTerrainHeight(uint32_t _x, uint32_t _y)
-   {
-      for (int32_t area_y = -m_brush.m_size; area_y < m_brush.m_size; ++area_y)
-      {
-         for (int32_t area_x = -m_brush.m_size; area_x < m_brush.m_size; ++area_x)
-         {
-            int32_t brush_x = _x + area_x;
-            if (brush_x < 0 || brush_x > (int32_t)s_terrainSize) continue;
-            int32_t brush_y = _y + area_y;
-            if (brush_y < 0 || brush_y > (int32_t)s_terrainSize) continue;
-
-            uint32_t heightMapPos = (brush_y * s_terrainSize) + brush_x;
-            float height = (float)m_terrain.m_heightMap[heightMapPos];
-
-            // Brush attenuation
-            float a2 = (float)(area_x * area_x);
-            float b2 = (float)(area_y * area_y);
-            float brushAttn = m_brush.m_size - sqrtf(a2 + b2);
-            
-            // Raise/Lower and scale by brush power.
-            height += bx::fclamp(brushAttn * m_brush.m_power, 0.0, m_brush.m_power) * m_brush.m_raise ? 1.0 : -1.0;
-
-            m_terrain.m_heightMap[heightMapPos] = (uint8_t)bx::fclamp(height, 0.0, 255.0);
-            m_terrain.m_dirty = true;
-         }
-      }
-   }
-
-   void mousePickTerrain()
-   {
-      float ray_clip[4];
-      ray_clip[0] = ((2.0f * m_mouseState.m_mx) / m_width - 1.0f) * -1.0f;
-      ray_clip[1] = ((1.0f - (2.0f * m_mouseState.m_my) / m_height)) * -1.0f;
-      ray_clip[2] = -1.0;
-      ray_clip[3] = 1.0;
-
-      float invProjMtx[16];
-      bx::mtxInverse(invProjMtx, m_projMtx);
-
-      float ray_eye[4];
-      bx::vec4MulMtx(ray_eye, ray_clip, invProjMtx);
-      ray_eye[2] = -1.0f;
-      ray_eye[3] = 0.0f;
-
-      float invViewMtx[16];
-      bx::mtxInverse(invViewMtx, m_viewMtx);
-
-      float ray_world[4];
-      bx::vec4MulMtx(ray_world, ray_eye, invViewMtx);
-
-      float ray_dir[3];
-      bx::vec3Norm(ray_dir, ray_world);
-      ray_dir[0] *= -1.0;
-      ray_dir[1] *= -1.0;
-      ray_dir[2] *= -1.0;
-
-      float pos[3];
-      cameraGetPosition(pos);
-      for (int i = 0; i < 1000; ++i)
-      {
-         bx::vec3Add(pos, pos, ray_dir);
-
-         if (pos[0] < 0 || pos[0] > s_terrainSize || pos[2] < 0 || pos[2] > s_terrainSize)
-            continue;
-
-         uint32_t heightMapPos = ((uint32_t)pos[2] * s_terrainSize) + (uint32_t)pos[0];
-         if ( pos[1] < m_terrain.m_heightMap[heightMapPos] )
-         {
-            paintTerrainHeight((uint32_t)pos[0], (uint32_t)pos[2]);
-            return;
-         }
-      }
-   }
-
-   bool update() BX_OVERRIDE
-   {
-      if (!entry::processEvents(m_width, m_height, m_debug, m_reset, &m_mouseState) )
-      {      
-         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;
-         const float deltaTime = float(frameTime/freq);
-
-         // Use m_debug font to print information about this example.
-         bgfx::dbgTextClear();
-         bgfx::dbgTextPrintf(0, 1, 0x4f, "bgfx/examples/27-terrain");
-         bgfx::dbgTextPrintf(0, 2, 0x6f, "Description: Terrain painting example.");
-         bgfx::dbgTextPrintf(0, 3, 0x0f, "Frame: % 7.3f[ms]", double(frameTime)*toMs);
-
-         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
-               , m_width
-               , m_height
-               );
-
-         imguiBeginScrollArea("Settings", m_width - m_width / 5 - 10, 10, m_width / 5, m_height / 3, &m_scrollArea);
-         imguiSeparatorLine();
-
-         if (imguiCheck("Vertex Buffer", (m_terrain.m_mode == 0)) )
-         {
-            m_terrain.m_mode = 0;
-            m_terrain.m_dirty = true;
-         }
-
-         if (imguiCheck("Dynamic Vertex Buffer", (m_terrain.m_mode == 1)) )
-         {
-            m_terrain.m_mode = 1;
-            m_terrain.m_dirty = true;
-         }
-
-         if (imguiCheck("Height Texture", (m_terrain.m_mode == 2)) )
-         {
-            m_terrain.m_mode = 2;
-            m_terrain.m_dirty = true;
-         }
-
-         imguiSeparatorLine();
-
-         if (imguiCheck("Raise Terrain", m_brush.m_raise))
-         {
-            m_brush.m_raise = !m_brush.m_raise;
-         }
-
-         imguiSlider("Brush Size", m_brush.m_size, 1, 50);
-         imguiSlider("Brush Power", m_brush.m_power, 0.0f, 1.0f, 0.01f);
-
-         imguiEndScrollArea();
-         imguiEndFrame();
-
-         // Update camera.
-         cameraUpdate(deltaTime, m_mouseState);
-
-         bool leftMouseButtonDown = !!m_mouseState.m_buttons[entry::MouseButton::Left];
-         if (leftMouseButtonDown)
-         {
-            mousePickTerrain();
-         }
-
-         // Update terrain.
-         if (m_terrain.m_dirty)
-         {
-            updateTerrain();
-            m_terrain.m_dirty = false;
-         }
-
-         // Set view 0 default viewport.
-         bgfx::setViewRect(0, 0, 0, m_width, m_height);
-
-         cameraGetViewMtx(m_viewMtx);
-         bx::mtxProj(m_projMtx, 60.0f, float(m_width) / float(m_height), 0.1f, 2000.0f, s_originBottomLeft);
-
-         bgfx::setViewTransform(0, m_viewMtx, m_projMtx);
-         bgfx::setTransform(m_terrain.m_transform);
-
-         if (m_terrain.m_mode == 0)
-         {
-            bgfx::setVertexBuffer(m_vbh);
-            bgfx::setIndexBuffer(m_ibh);
-            bgfx::submit(0, m_terrainProgram);
-         }
-         else if (m_terrain.m_mode == 1)
-         {
-            bgfx::setVertexBuffer(m_dvbh);
-            bgfx::setIndexBuffer(m_dibh);
-            bgfx::submit(0, m_terrainProgram);
-         }
-         else if (m_terrain.m_mode == 2)
-         {
-            bgfx::setVertexBuffer(m_vbh);
-            bgfx::setIndexBuffer(m_ibh);
-            bgfx::setTexture(0, s_heightTexture, m_heightTexture);
-            bgfx::submit(0, m_terrainHeightTextureProgram);
-         }
-
-         // Advance to next frame. Rendering thread will be kicked to
-         // process submitted rendering primitives.
-         bgfx::frame();
-
-         return true;
-      }
-
-      return false;
-   }
-
-   bgfx::VertexBufferHandle m_vbh;
-   bgfx::IndexBufferHandle m_ibh;
-   bgfx::DynamicVertexBufferHandle m_dvbh;
-   bgfx::DynamicIndexBufferHandle m_dibh;
-   bgfx::ProgramHandle m_terrainProgram;
-   bgfx::ProgramHandle m_terrainHeightTextureProgram;
-   bgfx::UniformHandle s_heightTexture;
-   bgfx::TextureHandle m_heightTexture;
-
-   float m_viewMtx[16];
-   float m_projMtx[16];
-
-   uint32_t m_width;
-   uint32_t m_height;
-   uint32_t m_debug;
-   uint32_t m_reset;
-
-   uint32_t m_oldWidth;
-   uint32_t m_oldHeight;
-   uint32_t m_oldReset;
-
-   int32_t m_scrollArea;
-
-   TerrainData m_terrain;
-   BrushData m_brush;
-
-   entry::MouseState m_mouseState;
-
-   int64_t m_timeOffset;
+		m_terrain.m_dirty     = true;
+		m_terrain.m_vertices  = new PosTexCoord0Vertex[s_terrainSize * s_terrainSize];
+		m_terrain.m_indices   = new uint16_t[s_terrainSize * s_terrainSize * 6];
+		m_terrain.m_heightMap = new uint8_t[s_terrainSize * s_terrainSize];
+
+		bx::mtxSRT(m_terrain.m_transform, 1.0f, 1.0f, 1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f);
+		memset(m_terrain.m_heightMap, 0, sizeof(uint8_t) * s_terrainSize * s_terrainSize);
+
+		cameraCreate();
+
+		const float initialPos[3] = { 0.0f, 15.0f, 0.0f };
+		cameraSetPosition(initialPos);
+		cameraSetVerticalAngle(0.0f);
+	}
+
+	virtual int shutdown() BX_OVERRIDE
+	{
+		// Cleanup.
+		cameraDestroy();
+		imguiDestroy();
+
+		if (bgfx::isValid(m_ibh) )
+		{
+			bgfx::destroyIndexBuffer(m_ibh);
+		}
+
+		if (bgfx::isValid(m_vbh) )
+		{
+			bgfx::destroyVertexBuffer(m_vbh);
+		}
+
+		if (bgfx::isValid(m_dibh) )
+		{
+			bgfx::destroyDynamicIndexBuffer(m_dibh);
+		}
+
+		if (bgfx::isValid(m_dvbh) )
+		{
+			bgfx::destroyDynamicVertexBuffer(m_dvbh);
+		}
+
+		bgfx::destroyUniform(s_heightTexture);
+		if (bgfx::isValid(m_heightTexture) )
+		{
+			bgfx::destroyTexture(m_heightTexture);
+		}
+
+		bgfx::destroyProgram(m_terrainProgram);
+		bgfx::destroyProgram(m_terrainHeightTextureProgram);
+
+		delete[] m_terrain.m_vertices;
+		delete[] m_terrain.m_indices;
+		delete[] m_terrain.m_heightMap;
+
+		// Shutdown bgfx.
+		bgfx::shutdown();
+
+		return 0;
+	}
+
+	void updateTerrainMesh()
+	{
+		m_terrain.m_vertexCount = 0;
+		for (uint32_t y = 0; y < s_terrainSize; y++)
+		{
+			for (uint32_t x = 0; x < s_terrainSize; x++)
+			{
+				PosTexCoord0Vertex* vert = &m_terrain.m_vertices[m_terrain.m_vertexCount];
+				vert->m_x = (float)x;
+				vert->m_y = m_terrain.m_heightMap[(y * s_terrainSize) + x];
+				vert->m_z = (float)y;
+				vert->m_u = (float)x / (float)s_terrainSize;
+				vert->m_v = (float)y / (float)s_terrainSize;
+
+				m_terrain.m_vertexCount++;
+			}
+		}
+
+		m_terrain.m_indexCount = 0;
+		for (uint32_t y = 0; y < (s_terrainSize - 1); y++)
+		{
+			uint32_t y_offset = (y * s_terrainSize);
+			for (uint32_t x = 0; x < (s_terrainSize - 1); x++)
+			{
+				m_terrain.m_indices[m_terrain.m_indexCount + 0] = y_offset + x + 1;
+				m_terrain.m_indices[m_terrain.m_indexCount + 1] = y_offset + x + s_terrainSize;
+				m_terrain.m_indices[m_terrain.m_indexCount + 2] = y_offset + x;
+				m_terrain.m_indices[m_terrain.m_indexCount + 3] = y_offset + x + s_terrainSize + 1;
+				m_terrain.m_indices[m_terrain.m_indexCount + 4] = y_offset + x + s_terrainSize;
+				m_terrain.m_indices[m_terrain.m_indexCount + 5] = y_offset + x + 1;
+
+				m_terrain.m_indexCount += 6;
+			}
+		}
+	}
+
+	void updateTerrain()
+	{
+		const bgfx::Memory* mem;
+
+		// Vertex Buffer : Destroy and recreate a regular vertex buffer to update terrain.
+		if (m_terrain.m_mode == 0)
+		{
+			updateTerrainMesh();
+
+			if (bgfx::isValid(m_vbh) )
+			{
+				bgfx::destroyVertexBuffer(m_vbh);
+			}
+
+			mem = bgfx::makeRef(&m_terrain.m_vertices[0], sizeof(PosTexCoord0Vertex) * m_terrain.m_vertexCount);
+			m_vbh = bgfx::createVertexBuffer(mem, PosTexCoord0Vertex::ms_decl);
+
+			if (bgfx::isValid(m_ibh) )
+			{
+				bgfx::destroyIndexBuffer(m_ibh);
+			}
+
+			mem = bgfx::makeRef(&m_terrain.m_indices[0], sizeof(uint16_t) * m_terrain.m_indexCount);
+			m_ibh = bgfx::createIndexBuffer(mem);
+		}
+
+		// Dynamic Vertex Buffer : Utilize dynamic vertex buffer to update terrain.
+		if (m_terrain.m_mode == 1)
+		{
+			updateTerrainMesh();
+
+			if (!bgfx::isValid(m_dvbh) )
+			{
+				m_dvbh = bgfx::createDynamicVertexBuffer(m_terrain.m_vertexCount, PosTexCoord0Vertex::ms_decl);
+			}
+
+			mem = bgfx::makeRef(&m_terrain.m_vertices[0], sizeof(PosTexCoord0Vertex) * m_terrain.m_vertexCount);
+			bgfx::updateDynamicVertexBuffer(m_dvbh, 0, mem);
+
+			if (!bgfx::isValid(m_dibh) )
+			{
+				m_dibh = bgfx::createDynamicIndexBuffer(m_terrain.m_indexCount);
+			}
+
+			mem = bgfx::makeRef(&m_terrain.m_indices[0], sizeof(uint16_t) * m_terrain.m_indexCount);
+			bgfx::updateDynamicIndexBuffer(m_dibh, 0, mem);
+		}
+
+		// Height Texture: Update a height texture that is sampled in the terrain vertex shader.
+		if (m_terrain.m_mode == 2)
+		{
+			if (!bgfx::isValid(m_vbh) || !bgfx::isValid(m_ibh) )
+			{
+				updateTerrainMesh();
+
+				mem = bgfx::makeRef(&m_terrain.m_vertices[0], sizeof(PosTexCoord0Vertex) * m_terrain.m_vertexCount);
+				m_vbh = bgfx::createVertexBuffer(mem, PosTexCoord0Vertex::ms_decl);
+
+				mem = bgfx::makeRef(&m_terrain.m_indices[0], sizeof(uint16_t) * m_terrain.m_indexCount);
+				m_ibh = bgfx::createIndexBuffer(mem);
+			}
+
+			if (!bgfx::isValid(m_heightTexture) )
+			{
+				m_heightTexture = bgfx::createTexture2D(s_terrainSize, s_terrainSize, 1, bgfx::TextureFormat::R8);
+			}
+
+			mem = bgfx::makeRef(&m_terrain.m_heightMap[0], sizeof(uint8_t) * s_terrainSize * s_terrainSize);
+			bgfx::updateTexture2D(m_heightTexture, 0, 0, 0, s_terrainSize, s_terrainSize, mem);
+		}
+	}
+
+	void paintTerrainHeight(uint32_t _x, uint32_t _y)
+	{
+		for (int32_t area_y = -m_brush.m_size; area_y < m_brush.m_size; ++area_y)
+		{
+			for (int32_t area_x = -m_brush.m_size; area_x < m_brush.m_size; ++area_x)
+			{
+				int32_t brush_x = _x + area_x;
+				if (brush_x < 0
+				||  brush_x > (int32_t)s_terrainSize)
+				{
+					continue;
+				}
+
+				int32_t brush_y = _y + area_y;
+				if (brush_y < 0
+				||  brush_y > (int32_t)s_terrainSize)
+				{
+					continue;
+				}
+
+				uint32_t heightMapPos = (brush_y * s_terrainSize) + brush_x;
+				float height = (float)m_terrain.m_heightMap[heightMapPos];
+
+				// Brush attenuation
+				float a2 = (float)(area_x * area_x);
+				float b2 = (float)(area_y * area_y);
+				float brushAttn = m_brush.m_size - sqrtf(a2 + b2);
+
+				// Raise/Lower and scale by brush power.
+				height += bx::fclamp(brushAttn * m_brush.m_power, 0.0, m_brush.m_power) * m_brush.m_raise ? 1.0 : -1.0;
+
+				m_terrain.m_heightMap[heightMapPos] = (uint8_t)bx::fclamp(height, 0.0, 255.0);
+				m_terrain.m_dirty = true;
+			}
+		}
+	}
+
+	void mousePickTerrain()
+	{
+		float ray_clip[4];
+		ray_clip[0] = ( (2.0f * m_mouseState.m_mx) / m_width - 1.0f) * -1.0f;
+		ray_clip[1] = ( (1.0f - (2.0f * m_mouseState.m_my) / m_height) ) * -1.0f;
+		ray_clip[2] = -1.0;
+		ray_clip[3] = 1.0;
+
+		float invProjMtx[16];
+		bx::mtxInverse(invProjMtx, m_projMtx);
+
+		float ray_eye[4];
+		bx::vec4MulMtx(ray_eye, ray_clip, invProjMtx);
+		ray_eye[2] = -1.0f;
+		ray_eye[3] = 0.0f;
+
+		float invViewMtx[16];
+		bx::mtxInverse(invViewMtx, m_viewMtx);
+
+		float ray_world[4];
+		bx::vec4MulMtx(ray_world, ray_eye, invViewMtx);
+
+		float ray_dir[3];
+		bx::vec3Norm(ray_dir, ray_world);
+		ray_dir[0] *= -1.0;
+		ray_dir[1] *= -1.0;
+		ray_dir[2] *= -1.0;
+
+		float pos[3];
+		cameraGetPosition(pos);
+		for (int i = 0; i < 1000; ++i)
+		{
+			bx::vec3Add(pos, pos, ray_dir);
+
+			if (pos[0] < 0
+			||  pos[0] > s_terrainSize
+			||  pos[2] < 0
+			||  pos[2] > s_terrainSize)
+			{
+				continue;
+			}
+
+			uint32_t heightMapPos = ( (uint32_t)pos[2] * s_terrainSize) + (uint32_t)pos[0];
+			if ( pos[1] < m_terrain.m_heightMap[heightMapPos] )
+			{
+				paintTerrainHeight( (uint32_t)pos[0], (uint32_t)pos[2]);
+				return;
+			}
+		}
+	}
+
+	bool update() BX_OVERRIDE
+	{
+		if (!entry::processEvents(m_width, m_height, m_debug, m_reset, &m_mouseState) )
+		{
+			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;
+			const float deltaTime = float(frameTime/freq);
+
+			// Use m_debug font to print information about this example.
+			bgfx::dbgTextClear();
+			bgfx::dbgTextPrintf(0, 1, 0x4f, "bgfx/examples/27-terrain");
+			bgfx::dbgTextPrintf(0, 2, 0x6f, "Description: Terrain painting example.");
+			bgfx::dbgTextPrintf(0, 3, 0x0f, "Frame: % 7.3f[ms]", double(frameTime)*toMs);
+
+			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
+					, m_width
+					, m_height
+					);
+
+			imguiBeginScrollArea("Settings", m_width - m_width / 5 - 10, 10, m_width / 5, m_height / 3, &m_scrollArea);
+			imguiSeparatorLine();
+
+			if (imguiCheck("Vertex Buffer", (m_terrain.m_mode == 0) ) )
+			{
+				m_terrain.m_mode = 0;
+				m_terrain.m_dirty = true;
+			}
+
+			if (imguiCheck("Dynamic Vertex Buffer", (m_terrain.m_mode == 1) ) )
+			{
+				m_terrain.m_mode = 1;
+				m_terrain.m_dirty = true;
+			}
+
+			if (imguiCheck("Height Texture", (m_terrain.m_mode == 2) ) )
+			{
+				m_terrain.m_mode = 2;
+				m_terrain.m_dirty = true;
+			}
+
+			imguiSeparatorLine();
+
+			if (imguiCheck("Raise Terrain", m_brush.m_raise) )
+			{
+				m_brush.m_raise = !m_brush.m_raise;
+			}
+
+			imguiSlider("Brush Size", m_brush.m_size, 1, 50);
+			imguiSlider("Brush Power", m_brush.m_power, 0.0f, 1.0f, 0.01f);
+
+			imguiEndScrollArea();
+			imguiEndFrame();
+
+			// Update camera.
+			cameraUpdate(deltaTime, m_mouseState);
+
+			bool leftMouseButtonDown = !!m_mouseState.m_buttons[entry::MouseButton::Left];
+			if (leftMouseButtonDown)
+			{
+				mousePickTerrain();
+			}
+
+			// Update terrain.
+			if (m_terrain.m_dirty)
+			{
+				updateTerrain();
+				m_terrain.m_dirty = false;
+			}
+
+			// Set view 0 default viewport.
+			bgfx::setViewRect(0, 0, 0, m_width, m_height);
+
+			cameraGetViewMtx(m_viewMtx);
+			bx::mtxProj(m_projMtx, 60.0f, float(m_width) / float(m_height), 0.1f, 2000.0f, s_originBottomLeft);
+
+			bgfx::setViewTransform(0, m_viewMtx, m_projMtx);
+			bgfx::setTransform(m_terrain.m_transform);
+
+			if (m_terrain.m_mode == 0)
+			{
+				bgfx::setVertexBuffer(m_vbh);
+				bgfx::setIndexBuffer(m_ibh);
+				bgfx::submit(0, m_terrainProgram);
+			}
+			else if (m_terrain.m_mode == 1)
+			{
+				bgfx::setVertexBuffer(m_dvbh);
+				bgfx::setIndexBuffer(m_dibh);
+				bgfx::submit(0, m_terrainProgram);
+			}
+			else if (m_terrain.m_mode == 2)
+			{
+				bgfx::setVertexBuffer(m_vbh);
+				bgfx::setIndexBuffer(m_ibh);
+				bgfx::setTexture(0, s_heightTexture, m_heightTexture);
+				bgfx::submit(0, m_terrainHeightTextureProgram);
+			}
+
+			// Advance to next frame. Rendering thread will be kicked to
+			// process submitted rendering primitives.
+			bgfx::frame();
+
+			return true;
+		}
+
+		return false;
+	}
+
+	bgfx::VertexBufferHandle m_vbh;
+	bgfx::IndexBufferHandle m_ibh;
+	bgfx::DynamicVertexBufferHandle m_dvbh;
+	bgfx::DynamicIndexBufferHandle m_dibh;
+	bgfx::ProgramHandle m_terrainProgram;
+	bgfx::ProgramHandle m_terrainHeightTextureProgram;
+	bgfx::UniformHandle s_heightTexture;
+	bgfx::TextureHandle m_heightTexture;
+
+	float m_viewMtx[16];
+	float m_projMtx[16];
+
+	uint32_t m_width;
+	uint32_t m_height;
+	uint32_t m_debug;
+	uint32_t m_reset;
+
+	uint32_t m_oldWidth;
+	uint32_t m_oldHeight;
+	uint32_t m_oldReset;
+
+	int32_t m_scrollArea;
+
+	TerrainData m_terrain;
+	BrushData m_brush;
+
+	entry::MouseState m_mouseState;
+
+	int64_t m_timeOffset;
 };
 
 ENTRY_IMPLEMENT_MAIN(Terrain);

examples/27-terrain/vs_terrain.sc

@@ -10,8 +10,8 @@ $output v_position, v_texcoord0
 
 void main()
 {
-    v_position = a_position.xyz;
-    v_texcoord0 = a_texcoord0;
- 
-    gl_Position = mul(u_modelViewProj, vec4(v_position.xyz, 1.0));
+	v_position = a_position.xyz;
+	v_texcoord0 = a_texcoord0;
+
+	gl_Position = mul(u_modelViewProj, vec4(v_position.xyz, 1.0));
 }

examples/27-terrain/vs_terrain_height_texture.sc

@@ -12,9 +12,9 @@ SAMPLER2D(s_heightTexture, 0);
 
 void main()
 {
-    v_texcoord0 = a_texcoord0;
-    v_position = a_position.xyz;
-    v_position.y = texture2DLod(s_heightTexture, a_texcoord0, 0).x * 255.0;
+	v_texcoord0 = a_texcoord0;
+	v_position = a_position.xyz;
+	v_position.y = texture2DLod(s_heightTexture, a_texcoord0, 0).x * 255.0;
 
-    gl_Position = mul(u_modelViewProj, vec4(v_position.xyz, 1.0));
+	gl_Position = mul(u_modelViewProj, vec4(v_position.xyz, 1.0));
 }