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    • By Achivai
      Hey, I am semi-new to 3d-programming and I've hit a snag. I have one object, let's call it Object A. This object has a long int array of 3d xyz-positions stored in it's vbo as an instanced attribute. I am using these numbers to instance object A a couple of thousand times. So far so good. 
      Now I've hit a point where I want to remove one of these instances of object A while the game is running, but I'm not quite sure how to go about it. At first my thought was to update the instanced attribute of Object A and change the positions to some dummy number that I could catch in the vertex shader and then decide there whether to draw the instance of Object A or not, but I think that would be expensive to do while the game is running, considering that it might have to be done several times every frame in some cases. 
      I'm not sure how to proceed, anyone have any tips?
    • By fleissi
      Hey guys!

      I'm new here and I recently started developing my own rendering engine. It's open source, based on OpenGL/DirectX and C++.
      The full source code is hosted on github:
      https://github.com/fleissna/flyEngine

      I would appreciate if people with experience in game development / engine desgin could take a look at my source code. I'm looking for honest, constructive criticism on how to improve the engine.
      I'm currently writing my master's thesis in computer science and in the recent year I've gone through all the basics about graphics programming, learned DirectX and OpenGL, read some articles on Nvidia GPU Gems, read books and integrated some of this stuff step by step into the engine.

      I know about the basics, but I feel like there is some missing link that I didn't get yet to merge all those little pieces together.

      Features I have so far:
      - Dynamic shader generation based on material properties
      - Dynamic sorting of meshes to be renderd based on shader and material
      - Rendering large amounts of static meshes
      - Hierarchical culling (detail + view frustum)
      - Limited support for dynamic (i.e. moving) meshes
      - Normal, Parallax and Relief Mapping implementations
      - Wind animations based on vertex displacement
      - A very basic integration of the Bullet physics engine
      - Procedural Grass generation
      - Some post processing effects (Depth of Field, Light Volumes, Screen Space Reflections, God Rays)
      - Caching mechanisms for textures, shaders, materials and meshes

      Features I would like to have:
      - Global illumination methods
      - Scalable physics
      - Occlusion culling
      - A nice procedural terrain generator
      - Scripting
      - Level Editing
      - Sound system
      - Optimization techniques

      Books I have so far:
      - Real-Time Rendering Third Edition
      - 3D Game Programming with DirectX 11
      - Vulkan Cookbook (not started yet)

      I hope you guys can take a look at my source code and if you're really motivated, feel free to contribute :-)
      There are some videos on youtube that demonstrate some of the features:
      Procedural grass on the GPU
      Procedural Terrain Engine
      Quadtree detail and view frustum culling

      The long term goal is to turn this into a commercial game engine. I'm aware that this is a very ambitious goal, but I'm sure it's possible if you work hard for it.

      Bye,

      Phil
    • By tj8146
      I have attached my project in a .zip file if you wish to run it for yourself.
      I am making a simple 2d top-down game and I am trying to run my code to see if my window creation is working and to see if my timer is also working with it. Every time I run it though I get errors. And when I fix those errors, more come, then the same errors keep appearing. I end up just going round in circles.  Is there anyone who could help with this? 
       
      Errors when I build my code:
      1>Renderer.cpp 1>c:\users\documents\opengl\game\game\renderer.h(15): error C2039: 'string': is not a member of 'std' 1>c:\program files (x86)\windows kits\10\include\10.0.16299.0\ucrt\stddef.h(18): note: see declaration of 'std' 1>c:\users\documents\opengl\game\game\renderer.h(15): error C2061: syntax error: identifier 'string' 1>c:\users\documents\opengl\game\game\renderer.cpp(28): error C2511: 'bool Game::Rendering::initialize(int,int,bool,std::string)': overloaded member function not found in 'Game::Rendering' 1>c:\users\documents\opengl\game\game\renderer.h(9): note: see declaration of 'Game::Rendering' 1>c:\users\documents\opengl\game\game\renderer.cpp(35): error C2597: illegal reference to non-static member 'Game::Rendering::window' 1>c:\users\documents\opengl\game\game\renderer.cpp(36): error C2597: illegal reference to non-static member 'Game::Rendering::window' 1>c:\users\documents\opengl\game\game\renderer.cpp(43): error C2597: illegal reference to non-static member 'Game::Rendering::window' 1>Done building project "Game.vcxproj" -- FAILED. ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========  
       
      Renderer.cpp
      #include <GL/glew.h> #include <GLFW/glfw3.h> #include "Renderer.h" #include "Timer.h" #include <iostream> namespace Game { GLFWwindow* window; /* Initialize the library */ Rendering::Rendering() { mClock = new Clock; } Rendering::~Rendering() { shutdown(); } bool Rendering::initialize(uint width, uint height, bool fullscreen, std::string window_title) { if (!glfwInit()) { return -1; } /* Create a windowed mode window and its OpenGL context */ window = glfwCreateWindow(640, 480, "Hello World", NULL, NULL); if (!window) { glfwTerminate(); return -1; } /* Make the window's context current */ glfwMakeContextCurrent(window); glViewport(0, 0, (GLsizei)width, (GLsizei)height); glOrtho(0, (GLsizei)width, (GLsizei)height, 0, 1, -1); glMatrixMode(GL_PROJECTION); glLoadIdentity(); glfwSwapInterval(1); glEnable(GL_SMOOTH); glEnable(GL_DEPTH_TEST); glEnable(GL_BLEND); glDepthFunc(GL_LEQUAL); glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); glEnable(GL_TEXTURE_2D); glLoadIdentity(); return true; } bool Rendering::render() { /* Loop until the user closes the window */ if (!glfwWindowShouldClose(window)) return false; /* Render here */ mClock->reset(); glfwPollEvents(); if (mClock->step()) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glfwSwapBuffers(window); mClock->update(); } return true; } void Rendering::shutdown() { glfwDestroyWindow(window); glfwTerminate(); } GLFWwindow* Rendering::getCurrentWindow() { return window; } } Renderer.h
      #pragma once namespace Game { class Clock; class Rendering { public: Rendering(); ~Rendering(); bool initialize(uint width, uint height, bool fullscreen, std::string window_title = "Rendering window"); void shutdown(); bool render(); GLFWwindow* getCurrentWindow(); private: GLFWwindow * window; Clock* mClock; }; } Timer.cpp
      #include <GL/glew.h> #include <GLFW/glfw3.h> #include <time.h> #include "Timer.h" namespace Game { Clock::Clock() : mTicksPerSecond(50), mSkipTics(1000 / mTicksPerSecond), mMaxFrameSkip(10), mLoops(0) { mLastTick = tick(); } Clock::~Clock() { } bool Clock::step() { if (tick() > mLastTick && mLoops < mMaxFrameSkip) return true; return false; } void Clock::reset() { mLoops = 0; } void Clock::update() { mLastTick += mSkipTics; mLoops++; } clock_t Clock::tick() { return clock(); } } TImer.h
      #pragma once #include "Common.h" namespace Game { class Clock { public: Clock(); ~Clock(); void update(); bool step(); void reset(); clock_t tick(); private: uint mTicksPerSecond; ufloat mSkipTics; uint mMaxFrameSkip; uint mLoops; uint mLastTick; }; } Common.h
      #pragma once #include <cstdio> #include <cstdlib> #include <ctime> #include <cstring> #include <cmath> #include <iostream> namespace Game { typedef unsigned char uchar; typedef unsigned short ushort; typedef unsigned int uint; typedef unsigned long ulong; typedef float ufloat; }  
      Game.zip
    • By lxjk
      Hi guys,
      There are many ways to do light culling in tile-based shading. I've been playing with this idea for a while, and just want to throw it out there.
      Because tile frustums are general small compared to light radius, I tried using cone test to reduce false positives introduced by commonly used sphere-frustum test.
      On top of that, I use distance to camera rather than depth for near/far test (aka. sliced by spheres).
      This method can be naturally extended to clustered light culling as well.
      The following image shows the general ideas

       
      Performance-wise I get around 15% improvement over sphere-frustum test. You can also see how a single light performs as the following: from left to right (1) standard rendering of a point light; then tiles passed the test of (2) sphere-frustum test; (3) cone test; (4) spherical-sliced cone test
       

       
      I put the details in my blog post (https://lxjk.github.io/2018/03/25/Improve-Tile-based-Light-Culling-with-Spherical-sliced-Cone.html), GLSL source code included!
       
      Eric
    • By Fadey Duh
      Good evening everyone!

      I was wondering if there is something equivalent of  GL_NV_blend_equation_advanced for AMD?
      Basically I'm trying to find more compatible version of it.

      Thank you!
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OpenGL Loading bitmaps/targas in OpenGL

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Ok, I have tried time and time again. I have written a basic load bitmap function and load targa function, but they both don''t work at all. I''ll post the code and see if you can help me. GLImage class definition: (look at the IMAGE struct I made since that is important too)
#ifndef GLIMAGE
#define GLIMAGE

//  Define the universal bitmap id
#define BITMAP_ID 0x4D42

#include "stdio.h"	//  Holds the file manipulation routines

//  Structure that holds pertinent information about image formats
typedef struct
{
	short int		width;		//  Width of the image
	short int		height;		//  Height of the image
	unsigned char	*data;		//  Data of the image
} IMAGE;

//  The definition fo the GLImage class
class GLImage
{
	private:
		FILE				*file;				//  The file pointer

		//  Bitmap variables
		IMAGE				*bmpImage;			//  Structure that holds pertinent information about the Windows bitmap format
		BITMAPFILEHEADER	bitmapFileHeader;	//  The bitmap file header
		BITMAPINFOHEADER	bitmapInfoHeader;	//  The bitmap information header

		//  Targa variables
		IMAGE				*tgaImage;			//  Structure that holds pertinent information about the Targa image format
		unsigned char		imageTypeCode;		//  The image type (i.e. 1, 2, or 3)
		unsigned char		bitCount;			//  The bit count of the Targa image
		unsigned char		ucharBad;			//  Garbage unsigned char data
		short int			sintBad;			//  Garbage short int data
		long				imageSize;			//  Size of the TGA image
		int					colorMode;			//  Holds color mode - 4 for RGBA  - 3 for RGB

	public:
		//  Loads a Windows bitmap file
		IMAGE* LoadBMPFile(char *filename);

		//  Loads a Targa image format file
		IMAGE* LoadTGAFile(char *filename);
};

#endif
Ok that was the class, here are the function declerations:
//  Include neccessary header files
#include "stdafx.h"		//  Header file for Windows
#include "GLImage.h"	//  Header file for the GLImage class

//  Loads a Windows bitmap file
IMAGE* GLImage::LoadBMPFile(char* filename)
{
	//  Open the filename in "read binary" mode
	file = fopen(filename, "rb");

	//  If the file couldn''t be opened return NULL
	if(file == NULL)
		return NULL;

	//  Read the bitmap file header
	fread(&bitmapFileHeader, sizeof(BITMAPFILEHEADER), 1, file);

	//  Verify that this is a bitmap by checking for the universal bitmap ID
	if(bitmapFileHeader.bfType != BITMAP_ID)
	{
		//  This is not a bitmap so close the file and return NULL
		fclose(file);

		return NULL;
	}

	//  Read the bitmap information header
	fread(&bitmapInfoHeader, sizeof(BITMAPINFOHEADER), 1, file);

	//  Move the file pointer to the beginning of the bitmap data
	fseek(file, bitmapFileHeader.bfOffBits, SEEK_SET);

	//  Allocate new space for the bmpImage
	bmpImage = new IMAGE;

	if(bmpImage == NULL)
	{
		//  Memory allocation failed so free the bmpImage, close the file, and return NULL
		delete bmpImage;
		fclose(file);

		return NULL;
	}

	//  Allocate enough memory for the bitmap image data
	bmpImage->data = new unsigned char[bitmapInfoHeader.biSizeImage];

	//  Verify memory allocation
	if(bmpImage->data == NULL)
	{
		//  Memory allocation failed so free the bitmapImage data, free the bmpImage, close the file, and return NULL
		delete [] bmpImage->data;
		delete bmpImage;
		fclose(file);

		return NULL;
	}

	//  Read in the bitmap image data
	fread(bmpImage->data, 1, bitmapInfoHeader.biSizeImage, file);

	//  Make sure the bitmap image data was read
	if(bmpImage->data == NULL)
	{
		//  Bitmap image was not read so free the bitmapImage data, free the bmpImage, close the file, and return NULL
		delete [] bmpImage->data;
		delete bmpImage;
		fclose(file);

		return NULL;
	}

	unsigned char tempRGB = NULL;	//  Temporary BGR->RGB swap variable

	//  Swap the R and B values to get RGB since the bitmap color format is in BGR
	for(int imageIdx = 0; imageIdx < bitmapInfoHeader.biSizeImage; imageIdx += 3)
	{
		tempRGB = bmpImage->data[imageIdx];
		bmpImage->data[imageIdx] = bmpImage->data[imageIdx + 2];
		bmpImage->data[imageIdx + 2] = tempRGB;
	}

	fclose(file);			//  Close the file

	return bmpImage;		//  Return the bitmap image since it was a success
}

//  Loads a Targa image format file
IMAGE* GLImage::LoadTGAFile(char *filename)
{
	//  Open the filename in "read binary" mode
	file = fopen(filename, "rb");

	//  If the file couldn''t be opened return NULL
	if(file == NULL)
		return NULL;

	//  Read first two bytes of data we don''t need
	fread(&ucharBad, sizeof(unsigned char), 1, file);
	fread(&ucharBad, sizeof(unsigned char), 1, file);

	//  Read in the image type
	fread(&imageTypeCode, sizeof(unsigned char), 1, file);

	//  Currently supported Targa file formats are 2-Uncompressed RGB and 3-Uncompressed black and white
	if(imageTypeCode != 2 && imageTypeCode != 3)
	{
		//  If it is not a supported type of Targa image close the file and return NULL
		fclose(file);

		return NULL;
	}

	//  Read 13 bytes of data we don''t need
	fread(&sintBad, sizeof(short int), 1, file);
	fread(&sintBad, sizeof(short int), 1, file);
	fread(&ucharBad, sizeof(unsigned char), 1, file);
	fread(&sintBad, sizeof(short int), 1, file);
	fread(&sintBad, sizeof(short int), 1, file);

	//  Allocate new space for the tgaImage
	tgaImage = new IMAGE;

	if(tgaImage == NULL)
	{
		//  Memory allocation failed so free the tgaImage, close the file, and return NULL
		delete tgaImage;
		fclose(file);

		return NULL;
	}

	//  Read image dimensions
	fread(&tgaImage->width, sizeof(short int), 1, file);
	fread(&tgaImage->height, sizeof(short int), 1, file);

	//  Read image bit depth
	fread(&bitCount, sizeof(unsigned char), 1, file);

	//  Read one byte of data we don''t need
	fread(&ucharBad, sizeof(unsigned char), 1, file);

	//  colorMode -> 3 = BGR, 4 = BGRA
	colorMode = bitCount / 8;
	imageSize = tgaImage->width * tgaImage->height * colorMode;

	//  Allocate memory for the image data
	tgaImage->data = new unsigned char[sizeof(unsigned char) * imageSize];

	//  Verify memory allocation
	if(tgaImage->data == NULL)
	{
		//  Memory allocation failed so free the targaImage data, free the tgaImage, close the file, and return NULL
		delete [] tgaImage->data;
		delete tgaImage;
		fclose(file);

		return NULL;
	}
	
	//  Read in the image data
	fread(tgaImage->data, sizeof(unsigned char), imageSize, file);

	//  Make sure the targa image data was read
	if(tgaImage->data == NULL)
	{
		//  Targa image was not read so free the targaImage data, free the tgaImage, close the file, and return NULL
		delete [] tgaImage->data;
		delete tgaImage;
		fclose(file);

		return NULL;
	}

	unsigned char colorSwap;	//  Swap variable used to exchange the R and B values

	//  Change BGR to RGB so OpenGL can read the image data
	for(int imageIdx = 0; imageIdx < imageSize; imageIdx += colorMode)
	{
		colorSwap = tgaImage->data[imageIdx];
		tgaImage->data[imageIdx] = tgaImage->data[imageIdx + 2];
		tgaImage->data[imageIdx + 2] = colorSwap;
	}

	fclose(file);		//  Close the file

	return tgaImage;	//  Loading of the TGA file was a successs
}
I think the way to use it in the code is self-explanatory if you have done this type of thing before. It goes a little like this: texture; IMAGE* image; GLImage i; // Load The Bitmap, Check For Errors, If Bitmap''s Not Found Quit if (TextureImage[0]=LoadBMP("Data/Crate.bmp")) { glGenTextures(1, &texture); glBindTexture(GL_TEXTURE_2D, texture); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MAG_FILTER,GL_NEAREST); glTexParameteri(GL_TEXTURE_2D,GL_TEXTURE_MIN_FILTER,GL_NEAREST); glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, image->width, image->height, 0, GL_RGB, GL_UNSIGNED_BYTE, image->data); } ..... Clear the memory ..... Etc. Ok, well if you have survived it this far ;-) I really appreciate that you took time out of your busy schedule to help me. If I was going to guess it is a pointer problem somewhere, but I can''t find it. I have also tried using the gluBuild2DMipmaps() in place of the glTexImage2D. I also get an error if the width is greater than 128. I tested it on three different comps with different video cards etc. and it still gave an error. SO, if you can help me in the smallest way my day will be a lot brighter. THANKS!

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Thats a lot of weird lookin code...
All I can say is, the bitmap/targa file width and height both need to be a power of two, ie 16, 32, 64, etc. Also... I wrote my own bitmap and targa loading routines and I found that some types swapped the blue and red colours round, I think it was blue and red anyway... So don''t be discouraged if you see weird colours.

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I had a problem with loading bitmaps as well. Per the advice of someone else here, I tried saving my bitmaps with PaintShop Pro 7 and everything work perfectly after that. You can download it free (demo) from their site. Just do a google search for PaintShop Pro and you''ll find it.

- Mike

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