opengl-3

问题 I'm writing shadow mapping in deferred shading. Here is my depth map for directional light (orthogonal projection): Below is my full-screen quad shader to render pixel's depth in light view space: #version 330 in vec2 texCoord; out vec3 fragColor; uniform mat4 lightViewProjMat; // lightView * lightProj uniform sampler2D sceneTexture; uniform sampler2D shadowMapTexture; uniform sampler2D scenePosTexture; void main() { vec4 fragPos = texture(scenePosTexture, texCoord); vec4 fragPosLightSpace =

问题 I have a very basic fragment shader which I want to output 'gl_PrimitiveID' to a fragment buffer object (FBO) which I have defined. Below is my fragment shader: #version 150 uniform vec4 colorConst; out vec4 fragColor; out uvec4 triID; void main(void) { fragColor = colorConst; triID.r = uint(gl_PrimitiveID); } I setup my FBO like this: GLuint renderbufId0; GLuint renderbufId1; GLuint depthbufId; GLuint framebufId; // generate render and frame buffer objects glGenRenderbuffers( 1,

问题 I am trying to create some simple polygons in openGL3.3. I have 2 types of objects with the following properties : Object 1 - 10 vertices (listed below, in order) stored in GL_ARRAY_BUFFER and use GL_TRIANGLE_FAN v x y z w v 0.0 0.0 1.0 1.0 v 0.0 1.0 0.1 1.0 v 0.71 0.71 0.1 1.0 v 1.0 0.0 0.1 1.0 v 0.71 -0.71 0.1 1.0 v 0.0 -1.0 0.1 1.0 v -0.71 -0.71 0.1 1.0 v -1.0 0.0 0.1 1.0 v -0.71 0.71 0.1 1.0 v 0.0 1.0 0.1 1.0 Object 2 - 4 vertices (listed below, in order) stored in GL_ARRAY_BUFFER and use

问题 Using OpenGL 3.3 core profile, I'm rendering a full-screen "quad" (as a single oversized triangle) via gl.DrawArrays(gl.TRIANGLES, 0, 3) with the following shaders. Vertex shader: #version 330 core #line 1 vec4 vx_Quad_gl_Position () { const float extent = 3; const vec2 pos[3] = vec2[](vec2(-1, -1), vec2(extent, -1), vec2(-1, extent)); return vec4(pos[gl_VertexID], 0, 1); } void main () { gl_Position = vx_Quad_gl_Position(); } Fragment shader: #version 330 core #line 1 out vec3 out_Color;

问题 I'm having trouble getting OpenGL 3.2 to run on Lion (osx 10.7.4) using Derelict3 and GLFW 3. Here's my test program: module glfw3Test; import std.stdio, std.conv; import derelict.glfw3.glfw3; import derelict.opengl3.gl3; string programName = "glfw3Test"; int width = 640; int height = 480; GLFWwindow window; void main() { // load opengl DerelictGL3.load(); // load GLFW DerelictGLFW3.load(); if(!glfwInit()) { glfwTerminate(); throw new Exception("Failed to create glcontext"); } writefln("GLFW:

问题 Can I expect users to be able to run software that uses OpenGL 3.x? Can Linux users who have open-source graphics drviers run OpenGL 3.x? I know that Mesa3D 7.8 only supports OpenGL 2.1. I also know that OS X Snow Leopard supports some but not all OpenGL 3.0 features. I don't know the situation on Leopard. I don't know the situation on XP, Vista, and Windows 7. I'd like to start learning OpenGL, and my interest lies more in scientific and engineering applications than games. I know I'll be

问题 This is the environment I currently use: Eclipse-Luna, C++11 on Linux Mint -Rebecca. When I try to use modern OpenGL like with VAOs or VBOs I get Compiler Errors such that methods could not be resolved. For Example: GLuint VaoID; //GLuint is working glGenVertexArrays(1, &VaoID); or: GLuint VboID; glGenBuffers(1, &VboID); glBindBuffer(GL_ARRAY_BUFFER, VboID); glBufferData(GL_ARRAY_BUFFER, vbo_size, data, usage); I checked the GL/gl.h, GL/glext.h and noticed that I have only got OpenGL 1.x

问题 I was reading this tutorial on MSAA in deferred shading, from 28byteslater.com. It says that in explicit multisampling we can access a particular sample. Could not we do the same from a regular texture that was bound to GL_TEXTURE_2D_MULTISAMPLE for instance? This was the shader code that I used to use earlier for accessing individual samples (without using explict multisampling): uniform sampler2DMS Diffuse; ivec2 Texcoord = ivec2(textureSize(Diffuse) * In.Texcoord); vec4 colorFirstSample =

问题 I'm trying to render the typical OpenGL color triangle in a gamma correct way by following this guide and consulting the SDL2 documentation on how to enable SRGB support on the default framebuffer. This is the code I've written, which draws the triangle: #include <SDL.h> // Header file generated with glLoadGen #include "gl_core_3_3.h" #include <cstdlib> void sdl_loop(SDL_Window* window); static const char* const vertexSource = R"( #version 330 in vec2 position; in vec3 color; out vec3 vs

问题 I came across a nasty problem in my program when i tried to use the same texture unit (number 0) for different texture types (i.e. a normal 2D texture and a cube map) in my shader. It appeared so that the GL issues a 502H (Invalid Operation) after the first glDrawArrays call. In my application code i load up the textures to different texture targets: void setup_textures() { unsigned int width, height; int components; unsigned int format; float param[8]; vector<unsigned char> pngData; GLenum