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• ### Similar Content

• By elect
Hi,
ok, so, we are having problems with our current mirror reflection implementation.
At the moment we are doing it very simple, so for the i-th frame, we calculate the reflection vectors given the viewPoint and some predefined points on the mirror surface (position and normal).
Then, using the least squared algorithm, we find the point that has the minimum distance from all these reflections vectors. This is going to be our virtual viewPoint (with the right orientation).
After that, we render offscreen to a texture by setting the OpenGL camera on the virtual viewPoint.
And finally we use the rendered texture on the mirror surface.
So far this has always been fine, but now we are having some more strong constraints on accuracy.
What are our best options given that:
- we have a dynamic scene, the mirror and parts of the scene can change continuously from frame to frame
- we have about 3k points (with normals) per mirror, calculated offline using some cad program (such as Catia)
- all the mirror are always perfectly spherical (with different radius vertically and horizontally) and they are always convex
- a scene can have up to 10 mirror
- it should be fast enough also for vr (Htc Vive) on fastest gpus (only desktops)

Looking around, some papers talk about calculating some caustic surface derivation offline, but I don't know if this suits my case
Also, another paper, used some acceleration structures to detect the intersection between the reflection vectors and the scene, and then adjust the corresponding texture coordinate. This looks the most accurate but also very heavy from a computational point of view.

Other than that, I couldn't find anything updated/exhaustive around, can you help me?

• Hello all,
I am currently working on a game engine for use with my game development that I would like to be as flexible as possible.  As such the exact requirements for how things should work can't be nailed down to a specific implementation and I am looking for, at least now, a default good average case scenario design.
Here is what I have implemented:
Deferred rendering using OpenGL Arbitrary number of lights and shadow mapping Each rendered object, as defined by a set of geometry, textures, animation data, and a model matrix is rendered with its own draw call Skeletal animations implemented on the GPU.   Model matrix transformation implemented on the GPU Frustum and octree culling for optimization Here are my questions and concerns:
Doing the skeletal animation on the GPU, currently, requires doing the skinning for each object multiple times per frame: once for the initial geometry rendering and once for the shadow map rendering for each light for which it is not culled.  This seems very inefficient.  Is there a way to do skeletal animation on the GPU only once across these render calls? Without doing the model matrix transformation on the CPU, I fail to see how I can easily batch objects with the same textures and shaders in a single draw call without passing a ton of matrix data to the GPU (an array of model matrices then an index for each vertex into that array for transformation purposes?) If I do the matrix transformations on the CPU, It seems I can't really do the skinning on the GPU as the pre-transformed vertexes will wreck havoc with the calculations, so this seems not viable unless I am missing something Overall it seems like simplest solution is to just do all of the vertex manipulation on the CPU and pass the pre-transformed data to the GPU, using vertex shaders that do basically nothing.  This doesn't seem the most efficient use of the graphics hardware, but could potentially reduce the number of draw calls needed.

Really, I am looking for some advice on how to proceed with this, how something like this is typically handled.  Are the multiple draw calls and skinning calculations not a huge deal?  I would LIKE to save as much of the CPU's time per frame so it can be tasked with other things, as to keep CPU resources open to the implementation of the engine.  However, that becomes a moot point if the GPU becomes a bottleneck.

• Hello!
I would like to introduce Diligent Engine, a project that I've been recently working on. Diligent Engine is a light-weight cross-platform abstraction layer between the application and the platform-specific graphics API. Its main goal is to take advantages of the next-generation APIs such as Direct3D12 and Vulkan, but at the same time provide support for older platforms via Direct3D11, OpenGL and OpenGLES. Diligent Engine exposes common front-end for all supported platforms and provides interoperability with underlying native API. Shader source code converter allows shaders authored in HLSL to be translated to GLSL and used on all platforms. Diligent Engine supports integration with Unity and is designed to be used as a graphics subsystem in a standalone game engine, Unity native plugin or any other 3D application. It is distributed under Apache 2.0 license and is free to use. Full source code is available for download on GitHub.
Features:
True cross-platform Exact same client code for all supported platforms and rendering backends No #if defined(_WIN32) ... #elif defined(LINUX) ... #elif defined(ANDROID) ... No #if defined(D3D11) ... #elif defined(D3D12) ... #elif defined(OPENGL) ... Exact same HLSL shaders run on all platforms and all backends Modular design Components are clearly separated logically and physically and can be used as needed Only take what you need for your project (do not want to keep samples and tutorials in your codebase? Simply remove Samples submodule. Only need core functionality? Use only Core submodule) No 15000 lines-of-code files Clear object-based interface No global states Key graphics features: Automatic shader resource binding designed to leverage the next-generation rendering APIs Multithreaded command buffer generation 50,000 draw calls at 300 fps with D3D12 backend Descriptor, memory and resource state management Modern c++ features to make code fast and reliable The following platforms and low-level APIs are currently supported:
Windows Desktop: Direct3D11, Direct3D12, OpenGL Universal Windows: Direct3D11, Direct3D12 Linux: OpenGL Android: OpenGLES MacOS: OpenGL iOS: OpenGLES API Basics
Initialization
The engine can perform initialization of the API or attach to already existing D3D11/D3D12 device or OpenGL/GLES context. For instance, the following code shows how the engine can be initialized in D3D12 mode:
#include "RenderDeviceFactoryD3D12.h" using namespace Diligent; // ...  GetEngineFactoryD3D12Type GetEngineFactoryD3D12 = nullptr; // Load the dll and import GetEngineFactoryD3D12() function LoadGraphicsEngineD3D12(GetEngineFactoryD3D12); auto *pFactoryD3D11 = GetEngineFactoryD3D12(); EngineD3D12Attribs EngD3D12Attribs; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[0] = 1024; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[1] = 32; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[2] = 16; EngD3D12Attribs.CPUDescriptorHeapAllocationSize[3] = 16; EngD3D12Attribs.NumCommandsToFlushCmdList = 64; RefCntAutoPtr<IRenderDevice> pRenderDevice; RefCntAutoPtr<IDeviceContext> pImmediateContext; SwapChainDesc SwapChainDesc; RefCntAutoPtr<ISwapChain> pSwapChain; pFactoryD3D11->CreateDeviceAndContextsD3D12( EngD3D12Attribs, &pRenderDevice, &pImmediateContext, 0 ); pFactoryD3D11->CreateSwapChainD3D12( pRenderDevice, pImmediateContext, SwapChainDesc, hWnd, &pSwapChain ); Creating Resources
Device resources are created by the render device. The two main resource types are buffers, which represent linear memory, and textures, which use memory layouts optimized for fast filtering. To create a buffer, you need to populate BufferDesc structure and call IRenderDevice::CreateBuffer(). The following code creates a uniform (constant) buffer:
BufferDesc BuffDesc; BufferDesc.Name = "Uniform buffer"; BuffDesc.BindFlags = BIND_UNIFORM_BUFFER; BuffDesc.Usage = USAGE_DYNAMIC; BuffDesc.uiSizeInBytes = sizeof(ShaderConstants); BuffDesc.CPUAccessFlags = CPU_ACCESS_WRITE; m_pDevice->CreateBuffer( BuffDesc, BufferData(), &m_pConstantBuffer ); Similar, to create a texture, populate TextureDesc structure and call IRenderDevice::CreateTexture() as in the following example:
TextureDesc TexDesc; TexDesc.Name = "My texture 2D"; TexDesc.Type = TEXTURE_TYPE_2D; TexDesc.Width = 1024; TexDesc.Height = 1024; TexDesc.Format = TEX_FORMAT_RGBA8_UNORM; TexDesc.Usage = USAGE_DEFAULT; TexDesc.BindFlags = BIND_SHADER_RESOURCE | BIND_RENDER_TARGET | BIND_UNORDERED_ACCESS; TexDesc.Name = "Sample 2D Texture"; m_pRenderDevice->CreateTexture( TexDesc, TextureData(), &m_pTestTex ); Initializing Pipeline State
Diligent Engine follows Direct3D12 style to configure the graphics/compute pipeline. One big Pipelines State Object (PSO) encompasses all required states (all shader stages, input layout description, depth stencil, rasterizer and blend state descriptions etc.)
To create a shader, populate ShaderCreationAttribs structure. An important member is ShaderCreationAttribs::SourceLanguage. The following are valid values for this member:
SHADER_SOURCE_LANGUAGE_DEFAULT  - The shader source format matches the underlying graphics API: HLSL for D3D11 or D3D12 mode, and GLSL for OpenGL and OpenGLES modes. SHADER_SOURCE_LANGUAGE_HLSL  - The shader source is in HLSL. For OpenGL and OpenGLES modes, the source code will be converted to GLSL. See shader converter for details. SHADER_SOURCE_LANGUAGE_GLSL  - The shader source is in GLSL. There is currently no GLSL to HLSL converter. To allow grouping of resources based on the frequency of expected change, Diligent Engine introduces classification of shader variables:
Static variables (SHADER_VARIABLE_TYPE_STATIC) are variables that are expected to be set only once. They may not be changed once a resource is bound to the variable. Such variables are intended to hold global constants such as camera attributes or global light attributes constant buffers. Mutable variables (SHADER_VARIABLE_TYPE_MUTABLE) define resources that are expected to change on a per-material frequency. Examples may include diffuse textures, normal maps etc. Dynamic variables (SHADER_VARIABLE_TYPE_DYNAMIC) are expected to change frequently and randomly. This post describes the resource binding model in Diligent Engine.
The following is an example of shader initialization:
To create a pipeline state object, define instance of PipelineStateDesc structure. The structure defines the pipeline specifics such as if the pipeline is a compute pipeline, number and format of render targets as well as depth-stencil format:
// This is a graphics pipeline PSODesc.IsComputePipeline = false; PSODesc.GraphicsPipeline.NumRenderTargets = 1; PSODesc.GraphicsPipeline.RTVFormats[0] = TEX_FORMAT_RGBA8_UNORM_SRGB; PSODesc.GraphicsPipeline.DSVFormat = TEX_FORMAT_D32_FLOAT; The structure also defines depth-stencil, rasterizer, blend state, input layout and other parameters. For instance, rasterizer state can be defined as in the code snippet below:
// Init rasterizer state RasterizerStateDesc &RasterizerDesc = PSODesc.GraphicsPipeline.RasterizerDesc; RasterizerDesc.FillMode = FILL_MODE_SOLID; RasterizerDesc.CullMode = CULL_MODE_NONE; RasterizerDesc.FrontCounterClockwise = True; RasterizerDesc.ScissorEnable = True; //RSDesc.MultisampleEnable = false; // do not allow msaa (fonts would be degraded) RasterizerDesc.AntialiasedLineEnable = False; When all fields are populated, call IRenderDevice::CreatePipelineState() to create the PSO:
Shader resource binding in Diligent Engine is based on grouping variables in 3 different groups (static, mutable and dynamic). Static variables are variables that are expected to be set only once. They may not be changed once a resource is bound to the variable. Such variables are intended to hold global constants such as camera attributes or global light attributes constant buffers. They are bound directly to the shader object:

m_pPSO->CreateShaderResourceBinding(&m_pSRB); Dynamic and mutable resources are then bound through SRB object:
m_pSRB->GetVariable(SHADER_TYPE_VERTEX, "tex2DDiffuse")->Set(pDiffuseTexSRV); m_pSRB->GetVariable(SHADER_TYPE_VERTEX, "cbRandomAttribs")->Set(pRandomAttrsCB); The difference between mutable and dynamic resources is that mutable ones can only be set once for every instance of a shader resource binding. Dynamic resources can be set multiple times. It is important to properly set the variable type as this may affect performance. Static variables are generally most efficient, followed by mutable. Dynamic variables are most expensive from performance point of view. This post explains shader resource binding in more details.
Setting the Pipeline State and Invoking Draw Command
Before any draw command can be invoked, all required vertex and index buffers as well as the pipeline state should be bound to the device context:
// Clear render target const float zero[4] = {0, 0, 0, 0}; m_pContext->ClearRenderTarget(nullptr, zero); // Set vertex and index buffers IBuffer *buffer[] = {m_pVertexBuffer}; Uint32 offsets[] = {0}; Uint32 strides[] = {sizeof(MyVertex)}; m_pContext->SetVertexBuffers(0, 1, buffer, strides, offsets, SET_VERTEX_BUFFERS_FLAG_RESET); m_pContext->SetIndexBuffer(m_pIndexBuffer, 0); m_pContext->SetPipelineState(m_pPSO); Also, all shader resources must be committed to the device context:
m_pContext->CommitShaderResources(m_pSRB, COMMIT_SHADER_RESOURCES_FLAG_TRANSITION_RESOURCES); When all required states and resources are bound, IDeviceContext::Draw() can be used to execute draw command or IDeviceContext::DispatchCompute() can be used to execute compute command. Note that for a draw command, graphics pipeline must be bound, and for dispatch command, compute pipeline must be bound. Draw() takes DrawAttribs structure as an argument. The structure members define all attributes required to perform the command (primitive topology, number of vertices or indices, if draw call is indexed or not, if draw call is instanced or not, if draw call is indirect or not, etc.). For example:
DrawAttribs attrs; attrs.IsIndexed = true; attrs.IndexType = VT_UINT16; attrs.NumIndices = 36; attrs.Topology = PRIMITIVE_TOPOLOGY_TRIANGLE_LIST; pContext->Draw(attrs); Tutorials and Samples
The GitHub repository contains a number of tutorials and sample applications that demonstrate the API usage.

AntTweakBar sample demonstrates how to use AntTweakBar library to create simple user interface.

Atmospheric scattering sample is a more advanced example. It demonstrates how Diligent Engine can be used to implement various rendering tasks: loading textures from files, using complex shaders, rendering to textures, using compute shaders and unordered access views, etc.

The repository includes Asteroids performance benchmark based on this demo developed by Intel. It renders 50,000 unique textured asteroids and lets compare performance of D3D11 and D3D12 implementations. Every asteroid is a combination of one of 1000 unique meshes and one of 10 unique textures.

Integration with Unity
Diligent Engine supports integration with Unity through Unity low-level native plugin interface. The engine relies on Native API Interoperability to attach to the graphics API initialized by Unity. After Diligent Engine device and context are created, they can be used us usual to create resources and issue rendering commands. GhostCubePlugin shows an example how Diligent Engine can be used to render a ghost cube only visible as a reflection in a mirror.

• By Yxjmir
I'm trying to load data from a .gltf file into a struct to use to load a .bin file. I don't think there is a problem with how the vertex positions are loaded, but with the indices. This is what I get when drawing with glDrawArrays(GL_LINES, ...):

Also, using glDrawElements gives a similar result. Since it looks like its drawing triangles using the wrong vertices for each face, I'm assuming it needs an index buffer/element buffer. (I'm not sure why there is a line going through part of it, it doesn't look like it belongs to a side, re-exported it without texture coordinates checked, and its not there)
I'm using jsoncpp to load the GLTF file, its format is based on JSON. Here is the gltf struct I'm using, and how I parse the file:
glBindVertexArray(g_pGame->m_VAO);
glDrawElements(GL_LINES, g_pGame->m_indices.size(), GL_UNSIGNED_BYTE, (void*)0); // Only shows with GL_UNSIGNED_BYTE
glDrawArrays(GL_LINES, 0, g_pGame->m_vertexCount);
So, I'm asking what type should I use for the indices? it doesn't seem to be unsigned short, which is what I selected with the Khronos Group Exporter for blender. Also, am I reading part or all of the .bin file wrong?
Test.gltf
Test.bin

• That means how do I use base DirectX or OpenGL api's to make a physics based destruction simulation?
Will it be just smart rendering or something else is required?

# OpenGL Texture Binding with Material Class

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## Recommended Posts

Im having a problem binding textures that I am loading from an .obj Material library. My texture loading code works if I load each texture individually, then all textures work great. But if a load the textures while parsing the Material Library file only the last texture loaded can be rendered. I have written a smaller program to try to get to the root of the problem. Basically, an instance of my Material class will load a texture and store the texture ID so that it can be bound when rendering. Any suggestions? Can anyone tell what I am doing wrong? Thanks for any help. Main.cpp:
#include <windows.h>		// Header File For Windows
#include <stdio.h>			// Header File For Standard Input/Output
#include <gl\gl.h>			// Header File For The OpenGL32 Library
#include <gl\glu.h>			// Header File For The GLu32 Library
#include <gl\glaux.h>		// Header File For The Glaux Library

#include <ios>
#include <iostream>
#include <string>
#include <tchar.h>
#include <windowsx.h>
#include <fstream>

#include <vector>

#include "Material.h"

using namespace std;

HDC			hDC=NULL;		// Private GDI Device Context
HGLRC		hRC=NULL;		// Permanent Rendering Context
HWND		hWnd=NULL;		// Holds Our Window Handle
HINSTANCE	hInstance;		// Holds The Instance Of The Application

bool	active=TRUE;		// Window Active Flag Set To TRUE By Default

// Log file
ofstream logFile("C:\\Documents and Settings\\Dave\\My Documents\\Visual Studio Projects\\TextureManager\\Debug\\log.txt", ios::out);

// Materials Container
std::vector<Material> materials;

LRESULT	CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);	// Declaration For WndProc

int numTexture = 0;

void checkGlErrors() {
int glError = 1;
while (glError != 0) {
glError = glGetError();
if (glError != 0) {
logFile << "[ERROR] glGetError = " << glError << endl;
}
}
}

// Call to load a Bitmap
{
logFile << "	loadBitmap called: file name = " << filename << endl;
FILE *file;				// File pointer
unsigned char *texture; // The pointer to the memory in which we will load the texture

// windows.h gives us these types to work with the Bitmap files
RGBTRIPLE rgb;

// Increment the texture count
numTexture++;
logFile << "		numTexture = " << numTexture << endl;

// Open the file for reading
if ( (file = fopen(filename, "rb")) == NULL) {
logFile << "		COULDN'T OPEN FILE" << endl;
return (-1);
} else {
logFile << "		The file has been opened for reading." << endl;
}

// Allocate the memory for our image (width * height * color deep)
// And fill it with zeros

int j = 0;
// We load an RGB value from the file

// And store it
texture[j+0] = rgb.rgbtRed;		// Red component
texture[j+1] = rgb.rgbtGreen;	// Green component
texture[j+2] = rgb.rgbtBlue;	// Blue component
texture[j+3] = 255;				// Alpha value
j += 4;							// Go to the next position
}

// Close the file stream
fclose(file);

// Bind the ID texture
glBindTexture(GL_TEXTURE_2D, numTexture);

// Define the 2d texture

// Sets the texture parameters
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);

// Use only the texture map
glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

// And create 2d mipmaps for the minifying function

// Free the memory used to load the texture
free(texture);

checkGlErrors();

// Returns texture ID for the new texture
int isTexture = glIsTexture(numTexture);
logFile << "		is a texture ? = " << isTexture << endl;
return (numTexture);
}

// Load an Alias Wavefront .obj Material Library

std::ifstream ifs(filename);

if (ifs) {
Material *pmat = 0;

while (!ifs.eof()) {

std::string s;
ifs >> s;

if (s == "newmtl") {
Material mat;
ifs >> mat.name;
materials.push_back(mat);
pmat = &(materials[materials.size()-1]);

} else if (s == "map_Kd") {

char buffer[512];
char* ptr = buffer;
ifs.getline(buffer,512);
while (*ptr == ' ' || *ptr == '\t') {
++ptr;
}

pmat->diffuseTextureName = ptr;
}
}
ifs.close();
return true;
}

return false;
}

// Resize the GL Scene
GLvoid ReSizeGLScene(GLsizei width, GLsizei height)
{
// Prevent A Divide By Zero By
if (height==0)
{
height=1;
}

// Reset The Current Viewport
glViewport(0,0,width,height);

// Select and Reset The Projection Matrix
glMatrixMode(GL_PROJECTION);

// Calculate The Aspect Ratio Of The Window
gluPerspective(75.0f,(GLfloat)width/(GLfloat)height,0.1f,100.0f);

// Select and Reset The Modelview Matrix
glMatrixMode(GL_MODELVIEW);
}

// All Setup For OpenGL Goes Here
int InitGL(GLvoid)
{
glEnable(GL_TEXTURE_2D);							// Enable Texture Mapping ( NEW )
glClearColor(0.0f, 0.0f, 0.0f, 0.5f);				// Black Background
glClearDepth(1.0f);									// Depth Buffer Setup
glEnable(GL_DEPTH_TEST);							// Enables Depth Testing
glDepthFunc(GL_LEQUAL);								// The Type Of Depth Testing To Do
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);	// Really Nice Perspective Calculations

logFile << "Materials NOT loaded." << endl;
} else {
logFile << "Materials loaded - materials.size() = " << materials.size() << endl;
}

// Print out the loaded materials props of interest
for (int i = 0; i < materials.size(); ++i) {
logFile << "Material " << i << ":" << endl;
logFile << "    name = " << materials.name << endl;
logFile << "    diffuseTextureName = " << materials.diffuseTextureName << endl;
logFile << "    diffuseTextureId = " << materials.diffuseTextureId << endl;
int isTexture = glIsTexture(materials.diffuseTextureId);
logFile << "    isTexture? = " << isTexture << endl;
}

// Check for errors
checkGlErrors();

// Initialization completed OK
return TRUE;
}

// Draw the scene
// Render 4 quads - each with a different Material
int DrawGLScene(GLvoid)
{
checkGlErrors();

// Clear The Screen And The Depth Buffer and Reset The View
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

// move the camera a little
glTranslatef(0.0f,0.0f,-5.0f);

int isTexture = glIsTexture(materials[0].diffuseTextureId);
logFile << "  glIsTexture? materials[0] = " << isTexture << endl;
materials[0].apply();
glTexCoord2f(0.0f, 0.0f); glVertex3f(-1.0f, -1.0f,  0.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f( 0.0f, -1.0f,  0.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f( 0.0f,  0.0f,  0.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(-1.0f,  0.0f,  0.0f);
glEnd();

isTexture = glIsTexture(materials[1].diffuseTextureId);
logFile << "  glIsTexture? materials[1] = " << isTexture << endl;
materials[1].apply();
glTexCoord2f(0.0f, 0.0f); glVertex3f(0.0f, 0.0f,  1.0f);
glTexCoord2f(1.0f, 0.0f); glVertex3f( 1.0f, 0.0f,  1.0f);
glTexCoord2f(1.0f, 1.0f); glVertex3f( 1.0f,  1.0f,  1.0f);
glTexCoord2f(0.0f, 1.0f); glVertex3f(0.0f,  1.0f,  1.0f);
glEnd();

return TRUE;
}

// Properly Kill The Window
GLvoid KillGLWindow(GLvoid)
{
// Do We Have A Rendering Context?
if (hRC)
{
// Are We Able To Release The DC And RC Contexts?
if (!wglMakeCurrent(NULL,NULL))
{
MessageBox(NULL,"Release Of DC And RC Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
}

// Are We Able To Delete The RC?
if (!wglDeleteContext(hRC))
{
MessageBox(NULL,"Release Rendering Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
}
hRC = NULL;
}
// Are We Able To Release The DC
if (hDC && !ReleaseDC(hWnd,hDC))
{
MessageBox(NULL,"Release Device Context Failed.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
hDC = NULL;
}
// Are We Able To Destroy The Window?
if (hWnd && !DestroyWindow(hWnd))
{
MessageBox(NULL,"Could Not Release hWnd.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
hWnd = NULL;
}
// Are We Able To Unregister Class
if (!UnregisterClass("OpenGL",hInstance))
{
MessageBox(NULL,"Could Not Unregister Class.","SHUTDOWN ERROR",MB_OK | MB_ICONINFORMATION);
hInstance = NULL;
}
}

// Create an OpenGL Window
BOOL CreateGLWindow(char* title, int width, int height, int bits, bool fullscreenflag)
{

logFile << "CreateGLWindow called." << endl;

GLuint		PixelFormat;			// Holds The Results After Searching For A Match
WNDCLASS	wc;						// Windows Class Structure
DWORD		dwExstyle;				// Window Extended style
DWORD		dwstyle;				// Window style
RECT		WindowRect;				// Grabs Rectangle Upper Left / Lower Right Values
WindowRect.left=(long)0;			// Set Left Value To 0
WindowRect.right=(long)width;		// Set Right Value To Requested Width
WindowRect.top=(long)0;				// Set Top Value To 0
WindowRect.bottom=(long)height;		// Set Bottom Value To Requested Height

hInstance			= GetModuleHandle(NULL);				// Grab An Instance For Our Window
wc.style			= CS_HREDRAW | CS_VREDRAW | CS_OWNDC;	// Redraw On Size, And Own DC For Window.
wc.lpfnWndProc		= (WNDPROC) WndProc;					// WndProc Handles Messages
wc.cbClsExtra		= 0;									// No Extra Window Data
wc.cbWndExtra		= 0;									// No Extra Window Data
wc.hInstance		= hInstance;							// Set The Instance
wc.hbrBackground	= NULL;									// No Background Required For GL
wc.lpszClassName	= "OpenGL";								// Set The Class Name

if (!RegisterClass(&wc))									// Attempt To Register The Window Class
{
MessageBox(NULL,"Failed To Register The Window Class.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE;											// Return FALSE
}

dwExstyle=WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;			// Window Extended style
dwstyle=WS_OVERLAPPEDWINDOW;							// Windows style

// Create The Window
if (!(hWnd=CreateWindowEx(	dwExstyle,							// Extended style For The Window
"OpenGL",							// Class Name
title,								// Window Title
dwstyle |							// Defined Window style
WS_CLIPSIBLINGS |					// Required Window style
WS_CLIPCHILDREN,					// Required Window style
0, 0,								// Window Position
WindowRect.right-WindowRect.left,	// Calculate Window Width
WindowRect.bottom-WindowRect.top,	// Calculate Window Height
NULL,								// No Parent Window
hInstance,							// Instance
NULL)))								// Dont Pass Anything To WM_CREATE
{
KillGLWindow();								// Reset The Display
MessageBox(NULL,"Window Creation Error.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE;								// Return FALSE
}

static	PIXELFORMATDESCRIPTOR pfd=				// pfd Tells Windows How We Want Things To Be
{
sizeof(PIXELFORMATDESCRIPTOR),				// Size Of This Pixel Format Descriptor
1,											// Version Number
PFD_DRAW_TO_WINDOW |						// Format Must Support Window
PFD_SUPPORT_OPENGL |						// Format Must Support OpenGL
PFD_DOUBLEBUFFER,							// Must Support Double Buffering
PFD_TYPE_RGBA,								// Request An RGBA Format
bits,										// Select Our Color Depth
0, 0, 0, 0, 0, 0,							// Color Bits Ignored
0,											// No Alpha Buffer
0,											// Shift Bit Ignored
0,											// No Accumulation Buffer
0, 0, 0, 0,									// Accumulation Bits Ignored
16,											// 16Bit Z-Buffer (Depth Buffer)
0,											// No Stencil Buffer
0,											// No Auxiliary Buffer
PFD_MAIN_PLANE,								// Main Drawing Layer
0,											// Reserved
0, 0, 0										// Layer Masks Ignored
};

if (!(hDC=GetDC(hWnd)))							// Did We Get A Device Context?
{
KillGLWindow();								// Reset The Display
MessageBox(NULL,"Can't Create A GL Device Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE;								// Return FALSE
}

if (!(PixelFormat=ChoosePixelFormat(hDC,&pfd)))	// Did Windows Find A Matching Pixel Format?
{
KillGLWindow();								// Reset The Display
MessageBox(NULL,"Can't Find A Suitable PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE;								// Return FALSE
}

if(!SetPixelFormat(hDC,PixelFormat,&pfd))		// Are We Able To Set The Pixel Format?
{
KillGLWindow();								// Reset The Display
MessageBox(NULL,"Can't Set The PixelFormat.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE;								// Return FALSE
}

if (!(hRC=wglCreateContext(hDC)))				// Are We Able To Get A Rendering Context?
{
KillGLWindow();								// Reset The Display
MessageBox(NULL,"Can't Create A GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE;								// Return FALSE
}

if(!wglMakeCurrent(hDC,hRC))					// Try To Activate The Rendering Context
{
KillGLWindow();								// Reset The Display
MessageBox(NULL,"Can't Activate The GL Rendering Context.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE;								// Return FALSE
}

ShowWindow(hWnd,SW_SHOW);						// Show The Window
SetForegroundWindow(hWnd);						// Slightly Higher Priority
SetFocus(hWnd);									// Sets Keyboard Focus To The Window
ReSizeGLScene(width, height);					// Set Up Our Perspective GL Screen

if (!InitGL())									// Initialize Our Newly Created GL Window
{
KillGLWindow();								// Reset The Display
MessageBox(NULL,"Initialization Failed.","ERROR",MB_OK|MB_ICONEXCLAMATION);
return FALSE;								// Return FALSE
}

return TRUE;									// Success
}

LRESULT CALLBACK WndProc(	HWND	hWnd,			// Handle For This Window
UINT	uMsg,			// Message For This Window
WPARAM	wParam,			// Additional Message Information
LPARAM	lParam)			// Additional Message Information
{
switch (uMsg)									// Check For Windows Messages
{
case WM_ACTIVATE:							// Watch For Window Activate Message
{
if (!HIWORD(wParam))					// Check Minimization State
{
active=TRUE;						// Program Is Active
}
else
{
active=FALSE;						// Program Is No Longer Active
}

}

case WM_SYSCOMMAND:							// Intercept System Commands
{
switch (wParam)							// Check System Calls
{
case SC_SCREENSAVE:					// Screensaver Trying To Start?
case SC_MONITORPOWER:				// Monitor Trying To Enter Powersave?
return 0;							// Prevent From Happening
}
break;									// Exit
}

case WM_CLOSE:								// Did We Receive A Close Message?
{
PostQuitMessage(0);						// Send A Quit Message
return 0;								// Jump Back
}

case WM_SIZE:								// Resize The OpenGL Window
{
ReSizeGLScene(LOWORD(lParam),HIWORD(lParam));  // LoWord=Width, HiWord=Height
return 0;								// Jump Back
}
}

// Pass All Unhandled Messages To DefWindowProc
return DefWindowProc(hWnd,uMsg,wParam,lParam);
}

int WINAPI WinMain(	HINSTANCE	hInstance,			// Instance
HINSTANCE	hPrevInstance,		// Previous Instance
LPSTR		lpCmdLine,			// Command Line Parameters
int			nCmdShow)			// Window Show State
{
MSG		msg;									// Windows Message Structure
BOOL	done=FALSE;								// Bool Variable To Exit Loop

// Create Our OpenGL Window
if (!CreateGLWindow("Materials", 640, 480, 16, false))
{
// Quit If Window Was Not Created
return 0;
}

// main loop
while (!done)
{
// Is There A Message Waiting?
if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE))
{
// Have We Received A Quit Message?
if (msg.message==WM_QUIT)
{
// If So done=TRUE
done=TRUE;
}
else
{
// Translate and Dispatch the message
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
else
{
// Draw The Scene.
if ((active && !DrawGLScene()))
{
// Quit signaled
done = TRUE;
}
else
{
// Swap Buffers (Double Buffering)
SwapBuffers(hDC);
}
}
}

// Shutdown
KillGLWindow();									// Kill The Window
return (msg.wParam);							// Exit The Program
}


End Main.cpp Material.h:
#ifndef MATERIAL_H
#define MATERIAL_H

#include <stdio.h>
#include <fstream>
#include <ios>
#include <iostream>
#include <string>

//#include "Engine.h"
#include <windows.h>		// Header File For Windows
#include <stdio.h>			// Header File For Standard Input/Output
#include <gl\gl.h>			// Header File For The OpenGL32 Library
#include <gl\glu.h>			// Header File For The GLu32 Library
#include <gl\glaux.h>		// Header File For The Glaux Library

using namespace std;

class Material
{
public:
Material();
Material(const char *name);
Material(const Material &mat);

virtual ~Material();

/** apply the material */
void apply() const;

std::string name;		//< material name

int illum;				//< don't know :| Seems to always be 4
float transparency[3];	//< transparency
float intensity;		//< intensity
float specularPower;	//< specular power
float bumpDepth;		//< bump map depth. Only used if bump is relevent.

mutable float ambientColor[4];	//< ambient
mutable float diffuseColor[4];	//< diffuse
mutable float specularColor[4];	//< specular

std::string ambientTextureName;		//< ambient texture map name
std::string diffuseTextureName;		//< diffuse texture map name
std::string specularTextureName;	//< specular texture map name
std::string bumpTextureName;		//< bump texture map name

// OpenGL texture IDs
unsigned int ambientTextureId;		//< ambient texture object ID
unsigned int diffuseTextureId;		//< diffuse texture object ID
unsigned int specularTextureId;		//< specular texture object ID
unsigned int bumpTextureId;			//< bump map texture object ID

private:
};

#endif


End Material.h Material.cpp:
#include "Material.h"

#include "TextureManager.h"
#include "Globals.h"

//#include "lesson6.h"

/**
* Material constructor
*/
Material::Material() : name(), illum(4), intensity(1), specularPower(10), bumpDepth(1),
ambientTextureName(), diffuseTextureName(), specularTextureName(), bumpTextureName() {

ambientColor[0] = ambientColor[1] = ambientColor[2] =
diffuseColor[0] = diffuseColor[1] = diffuseColor[2] =
specularColor[0] = specularColor[1] = specularColor[2] = 0;
ambientColor[3] = diffuseColor[3] = specularColor[3] = 1;
transparency[0] = transparency[1] = transparency[2] = 1;
ambientTextureId = diffuseTextureId = specularTextureId = bumpTextureId = 0;
}

/**
* Material Copy Constructor
*/
Material::Material(const Material& mat) {
ambientColor[0] = mat.ambientColor[0];
ambientColor[1] = mat.ambientColor[1];
ambientColor[2] = mat.ambientColor[2];
ambientColor[3] = mat.ambientColor[3];

diffuseColor[0] = mat.diffuseColor[0];
diffuseColor[1] = mat.diffuseColor[1];
diffuseColor[2] = mat.diffuseColor[2];
diffuseColor[3] = mat.diffuseColor[3];

specularColor[0] = mat.specularColor[0];
specularColor[1] = mat.specularColor[1];
specularColor[2] = mat.specularColor[2];
specularColor[3] = mat.specularColor[3];

transparency[0] = mat.transparency[0];
transparency[1] = mat.transparency[1];
transparency[2] = mat.transparency[2];

intensity = mat.intensity;
specularPower = mat.specularPower;
name = mat.name;
ambientTextureName = mat.ambientTextureName;
diffuseTextureName = mat.diffuseTextureName;
specularTextureName = mat.specularTextureName;
bumpTextureName = mat.bumpTextureName;
illum = mat.illum;
bumpDepth = mat.bumpDepth;

ambientTextureId = mat.ambientTextureId;
diffuseTextureId = mat.diffuseTextureId;
specularTextureId = mat.specularTextureId;
bumpTextureId = mat.bumpTextureId;
}

/**
* The material class destructor.
*/
Material::~Material() {
if (ambientTextureId) glDeleteTextures(1, &ambientTextureId);
if (diffuseTextureId) glDeleteTextures(1, &diffuseTextureId);
if (specularTextureId) glDeleteTextures(1, &specularTextureId);
if (bumpTextureId) glDeleteTextures(1, &bumpTextureId);
}

/**
*
*/
void Material::apply() const {

// HACK !?!??
glColor3f(1.0f, 1.0f, 1.0f);

float average_transp = (transparency[0]+transparency[1]+transparency[2])/3.0f;
ambientColor[3] = diffuseColor[3] = specularColor[3] = average_transp;
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, ambientColor);
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, diffuseColor);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specularColor);
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, specularPower);

if (diffuseTextureId) {
// maya always sets the diffuse color to black when a texture is applied.
float color[4] = {0.8f, 0.8f, 0.8f, average_transp};
glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, color);

// apply texture
glBindTexture(GL_TEXTURE_2D, diffuseTextureId);

// Enable texturing
glEnable(GL_TEXTURE_2D);
} else {
glDisable(GL_TEXTURE_2D);
}
}

/**
* Loads a bitmap and converts it to a texture.
* @return The new texture's ID.
*/
}


End Material.cpp Material Library file: newmtl grass illum 4 Kd 0.00 0.00 0.00 Ka 0.00 0.00 0.00 Tf 1.00 1.00 1.00 map_Kd grass.bmp Ni 1.00 Ks 0.33 0.33 0.33 Ns 0.06 newmtl Brick_dark_grout illum 4 Kd 0.00 0.00 0.00 Ka 0.00 0.00 0.00 Tf 1.00 1.00 1.00 map_Kd Brick_dark_grout.bmp Ni 1.00 Ks 0.33 0.33 0.33 Ns 0.06 end Material Library file [edit: added source tags -SiCrane]

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Could you post the contents of your logfile?

Enigma

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You need to call glGenTextures. You can't just assume gl will allow you to use sequential texture IDs. If you replace your numTexture stuff with glGenTextures it should work OK, I think.

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Here is the log file:

CreateGLWindow called.
loadBitmap called: file name = grass.bmp
numTexture = 1
The file has been opened for reading.
is a texture ? = 1
loadBitmap called: file name = Brick_dark_grout.bmp
numTexture = 2
The file has been opened for reading.
is a texture ? = 1
Materials loaded - materials.size() = 2
Material 0:
name = grass
diffuseTextureName = grass.bmp
diffuseTextureId = 1
isTexture? = 0
Material 1:
name = Brick_dark_grout
diffuseTextureName = Brick_dark_grout.bmp
diffuseTextureId = 2
isTexture? = 1
glIsTexture? materials[0] = 0
glIsTexture? materials[1] = 1
glIsTexture? materials[0] = 0
glIsTexture? materials[1] = 1
. . .

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mrb.

I don't think that that is the problem. If I change the code that loads the textures (init) to the following, all the textures work:
int InitGL(GLvoid)
{
glEnable(GL_TEXTURE_2D); // Enable Texture Mapping ( NEW )
glClearColor(0.0f, 0.0f, 0.0f, 0.5f); // Black Background
glClearDepth(1.0f); // Depth Buffer Setup
glEnable(GL_DEPTH_TEST); // Enables Depth Testing
glDepthFunc(GL_LEQUAL); // The Type Of Depth Testing To Do
glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); // Really Nice Perspective Calculations

// logFile << "Materials NOT loaded." << endl;
//} else {
// logFile << "Materials loaded - materials.size() = " << materials.size() << endl;
//}

Material mat1;
Material mat2;
materials.push_back(mat1);
materials.push_back(mat2);

// Print out the loaded materials props of interest
for (int i = 0; i < materials.size(); ++i) {
logFile << "Material " << i << ":" << endl;
logFile << " name = " << materials.name << endl;
logFile << " diffuseTextureName = " << materials.diffuseTextureName << endl;
logFile << " diffuseTextureId = " << materials.diffuseTextureId << endl;
int isTexture = glIsTexture(materials.diffuseTextureId);
logFile << " isTexture? = " << isTexture << endl;
}

// Check for errors
checkGlErrors();

// Initialization completed OK
return TRUE;
}

The difference is that I am explicitly calling the loadBitmap method for each texture instead of loading the Material library. I don't know why the texture IDs would be valid when I call loadBitmap() directly and not when I call it from loadMaterialFile() ???

I tried to use glGenTextures() to give me valid texture IDs like so:

GLunit name[1];
glGenTexture(1, name);

But, with this, each call to loadBitmap() returns the same ID! The Texture doesn't really get bound to it for some reason.

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Well, I can't see exactly why it's happening, unless the vector is resizing itself after a single push_back, but I'm almost certain your problem is the destructor for Material. When you push_back an element into a vector the vector stores a copy, which means the following sequence of operations occurs:
Material::Material(); // your default constructed material object
Material::Material(Material const &); // the vector copy constructs your object into storage
Material::~Material(); // your material object leaves scope and is destructed

The last of those calls will result in you calling glDeleteTextures for any set textures ids. None of your texture ids should be set in your object, but if the vector has to further copy them then glDeleteTextures will be called and your texture object will be deleted. To solve this you'll probably need to store a reference count in your Material object or work with (smart) pointers to Materials or any other equivalent technique.

By the way, this code:
char buffer[512];char* ptr = buffer;ifs.getline(buffer,512);while (*ptr == ' ' || *ptr == '\t') {	++ptr;}pmat->diffuseTextureName = ptr;

would be better implemented as:
std::getline(ifs, pmat->diffuseTextureName);std::string::size_type whitespace = pmat->diffuseTextureName.find_first_not_of(" \t");if (whitespace != std::string::npos){	pmat->diffuseTextureName = pmat->diffuseTextureName.substr(whitespace);}

Enigma