• Advertisement
  • Popular Tags

  • Popular Now

  • Advertisement
  • Similar Content

    • 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!
    • By Jens Eckervogt
      Hello guys, 
       
      Please tell me! 
      How do I know? Why does wavefront not show for me?
      I already checked I have non errors yet.
      using OpenTK; using System.Collections.Generic; using System.IO; using System.Text; namespace Tutorial_08.net.sourceskyboxer { public class WaveFrontLoader { private static List<Vector3> inPositions; private static List<Vector2> inTexcoords; private static List<Vector3> inNormals; private static List<float> positions; private static List<float> texcoords; private static List<int> indices; public static RawModel LoadObjModel(string filename, Loader loader) { inPositions = new List<Vector3>(); inTexcoords = new List<Vector2>(); inNormals = new List<Vector3>(); positions = new List<float>(); texcoords = new List<float>(); indices = new List<int>(); int nextIdx = 0; using (var reader = new StreamReader(File.Open("Contents/" + filename + ".obj", FileMode.Open), Encoding.UTF8)) { string line = reader.ReadLine(); int i = reader.Read(); while (true) { string[] currentLine = line.Split(); if (currentLine[0] == "v") { Vector3 pos = new Vector3(float.Parse(currentLine[1]), float.Parse(currentLine[2]), float.Parse(currentLine[3])); inPositions.Add(pos); if (currentLine[1] == "t") { Vector2 tex = new Vector2(float.Parse(currentLine[1]), float.Parse(currentLine[2])); inTexcoords.Add(tex); } if (currentLine[1] == "n") { Vector3 nom = new Vector3(float.Parse(currentLine[1]), float.Parse(currentLine[2]), float.Parse(currentLine[3])); inNormals.Add(nom); } } if (currentLine[0] == "f") { Vector3 pos = inPositions[0]; positions.Add(pos.X); positions.Add(pos.Y); positions.Add(pos.Z); Vector2 tc = inTexcoords[0]; texcoords.Add(tc.X); texcoords.Add(tc.Y); indices.Add(nextIdx); ++nextIdx; } reader.Close(); return loader.loadToVAO(positions.ToArray(), texcoords.ToArray(), indices.ToArray()); } } } } } And It have tried other method but it can't show for me.  I am mad now. Because any OpenTK developers won't help me.
      Please help me how do I fix.

      And my download (mega.nz) should it is original but I tried no success...
      - Add blend source and png file here I have tried tried,.....  
       
      PS: Why is our community not active? I wait very longer. Stop to lie me!
      Thanks !
  • Advertisement
  • Advertisement
Sign in to follow this  

OpenGL Render indexed data from Q3 BSP

This topic is 1149 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

Hi

 

I'm trying to render a Quake 3 BSP file using core OpenGL.  I have the file loaded ok ( using the same code from a old OpenGL program ) - but I can't work out how to translate the old way of glDrawElements into the new core way of drawing indexed arrays.

 

this is what I end up with - a scrambled mess

 

1z4ae52.png

 

So, once the BSP is loaded - I upload all the data to the GPU like this:

//-----------------------------------------------------------------------------
//
// Upload vertex arrays to GPU
bool bsp_uploadBspToGPU()
//-----------------------------------------------------------------------------
{
    //
    // Store model and all meshes in one VAO
    glGenVertexArrays(1, &bspVAO_ID);
    glBindVertexArray(bspVAO_ID);

//    GL_CHECK(glGenBuffers(1, &elementArrayID));
//    GL_CHECK(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementArrayID));
//    GL_CHECK(glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(m_numOfMeshIndexes * sizeof(int)), &m_pMeshIndex, GL_STATIC_DRAW));

    //
    // Load vertices into GPU
    GL_CHECK(glGenBuffers(1, &bspVBO_VERT));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_VERT));
//    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, m_numOfVerts * sizeof(tBSPVertex), &(m_pVerts[0].vPosition), GL_STATIC_DRAW));
    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, m_numOfVerts * sizeof(glm::vec3), &(m_pVerts[0].vPosition), GL_STATIC_DRAW));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, 0));
    //
    // Load texture coordinates into GPU
    GL_CHECK(glGenBuffers(1, &bspVBO_TEXCOORD));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_TEXCOORD));
//    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, m_numOfVerts * sizeof(tBSPVertex), &(m_pVerts[0].vTextureCoord), GL_STATIC_DRAW));
    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, m_numOfVerts * sizeof(glm::vec2), &(m_pVerts[0].vTextureCoord), GL_STATIC_DRAW));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, 0));

    //
    // Load lightmap coordinates into GPU
    GL_CHECK(glGenBuffers(1, &bspVBO_LIGHTMAP));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_LIGHTMAP));
//    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, m_numOfVerts * sizeof(tBSPVertex), &(m_pVerts[0].vLightmapCoord), GL_STATIC_DRAW));
    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, m_numOfVerts * sizeof(glm::vec2), &(m_pVerts[0].vLightmapCoord), GL_STATIC_DRAW));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, 0));

    //
    // Load normals into GPU
    GL_CHECK(glGenBuffers(1, &bspVBO_NORMALS));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_NORMALS));
//    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, m_numOfVerts * sizeof(tBSPVertex), &(m_pVerts[0].vNormal), GL_STATIC_DRAW));
    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, m_numOfVerts * sizeof(glm::vec3), &(m_pVerts[0].vNormal), GL_STATIC_DRAW));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, 0));

    glBindBuffer(GL_ARRAY_BUFFER, 0);
}

and after walking the BSP and finding all the viewable faces which I store in an array for later sorting, I then render each face like this:


//-----------------------------------------------------------------------------
//
// Actually draw the BSP face
void bsp_drawFace(tBSPFace *ptrFace)
//-----------------------------------------------------------------------------
{
    GL_ASSERT(glBindVertexArray(bspVAO_ID));

    GL_ASSERT(glUseProgram(shaderProgram[SHADER_GEOMETRY_PASS].programID));

    wrapglBindTexture(GL_TEXTURE0, texturesLoaded[TEX_WALL].texID);
    GL_ASSERT(glUniform1i(shaderProgram[SHADER_GEOMETRY_PASS].inTextureUnit, 0));

    GL_ASSERT(glUniformMatrix4fv(glGetUniformLocation(shaderProgram[SHADER_GEOMETRY_PASS].programID, "u_modelMat"), 1, false, glm::value_ptr(modelMatrix) ));

//    GL_ASSERT(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementArrayID));
//    GL_ASSERT(glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(int) * m_numOfMeshIndexes, &m_pMeshIndex[0], GL_STATIC_DRAW));

    GL_ASSERT(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_VERT));
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[SHADER_GEOMETRY_PASS].inVertsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[SHADER_GEOMETRY_PASS].inVertsID, 3, GL_FLOAT, GL_FALSE, 0, NULL));

    GL_ASSERT(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_TEXCOORD));
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[SHADER_GEOMETRY_PASS].inTextureCoordsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[SHADER_GEOMETRY_PASS].inTextureCoordsID, 2, GL_FLOAT, GL_FALSE, 0, NULL));

    GL_ASSERT(glDrawElements(GL_TRIANGLES, ptrFace->numOfVerts, GL_UNSIGNED_INT, &m_pMeshIndex[ptrFace->startVertIndex]));

//    GL_ASSERT(glDrawElements(GL_TRIANGLES, ptrFace->numMeshVerts, GL_UNSIGNED_INT, &m_pMeshIndex[ptrFace->meshVertIndex]));


    printf("Num verts in this face [ %i ] \n", ptrFace->numOfVerts);

    for (int i = 0; i != ptrFace->numOfVerts; i++)
    {
        printf("Index [ %i ] - [ %i ]\n", i, m_pMeshIndex[ptrFace->startVertIndex + i]);

    }

}

The data appears to be correct, ptrFace->numOfVerts seems to be the right number, and the indexes printed out seem correct as well.

<snip>

Num verts in this face [ 8 ] 
Index [ 0 ] - [ 0 ]
Index [ 1 ] - [ 2 ]
Index [ 2 ] - [ 4 ]
Index [ 3 ] - [ 0 ]
Index [ 4 ] - [ 1 ]
Index [ 5 ] - [ 2 ]
Index [ 6 ] - [ 2 ]
Index [ 7 ] - [ 6 ]

Num verts in this face [ 4 ] 
Index [ 0 ] - [ 4 ]
Index [ 1 ] - [ 0 ]
Index [ 2 ] - [ 4 ]
Index [ 3 ] - [ 5 ]

</snip>

I have also read that when using glDrawElements that you can use an indexed buffer as well, but I couldn't get that working either.

 

Any pointers on getting glDrawElements working correctly?

 

Thanks

Share this post


Link to post
Share on other sites
Advertisement

Seems like the problem is that your vertex data is interleaved and you're using them as if they were in their own arrays. You could create a single buffer and upload all vertex data in it, then use glVertexAttribPointer for each attribute and pass the offset in bytes for the last parameter. Also, the stride should be the size of the vertex.

// offset for position is 0
glEnableVertexAttribArray(position_index);
glVertexAttribPointer(position_index, 3, GL_FLOAT, GL_FALSE, sizeof(YourVertex), (void*)(0));

// offset for normal is the size of position which would be 3 floats
glEnableVertexAttribArray(position_index);
glVertexAttribPointer(normal_index, 3, GL_FLOAT, GL_FALSE, sizeof(YourVertex), (void*)(sizeof(float) * 3));

// ... and the offset for the next attribute would be sizeof(float) * (3 + 3)

And about index buffers, just use GL_ELEMENT_ARRAY_BUFFER, send the data and then call glDrawElements with 0 as the last parameter (which is the offset).

Edited by Sponji

Share this post


Link to post
Share on other sites

Seems like the problem is that your vertex data is interleaved and you're using them as if they were in their own arrays. You could create a single buffer and upload all vertex data in it, then use glVertexAttribPointer for each attribute and pass the offset in bytes for the last parameter. Also, the stride should be the size of the vertex.

// offset for position is 0
glEnableVertexAttribArray(position_index);
glVertexAttribPointer(position_index, 3, GL_FLOAT, GL_FALSE, sizeof(YourVertex), (void*)(0));

// offset for normal is the size of position which would be 3 floats
glEnableVertexAttribArray(position_index);
glVertexAttribPointer(normal_index, 3, GL_FLOAT, GL_FALSE, sizeof(YourVertex), (void*)(sizeof(float) * 3));

// ... and the offset for the next attribute would be sizeof(float) * (3 + 3)

And about index buffers, just use GL_ELEMENT_ARRAY_BUFFER, send the data and then call glDrawElements with 0 as the last parameter (which is the offset).

 

Ok - like this?

//-----------------------------------------------------------------------------
//
// Upload vertex arrays to GPU
bool bsp_uploadBspToGPU()
//-----------------------------------------------------------------------------
{
    //
    // Store model and all meshes in one VAO
    glGenVertexArrays(1, &bspVAO_ID);
    glBindVertexArray(bspVAO_ID);

    GL_CHECK(glGenBuffers(1, &elementArrayID));
    GL_CHECK(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementArrayID));
    GL_CHECK(glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(m_numOfMeshIndexes * sizeof(int)), &m_pMeshIndex, GL_STATIC_DRAW));
    //
    // Load vertices information into GPU
    GL_CHECK(glGenBuffers(1, &bspVBO_VERT));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_VERT));
    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, m_numOfVerts * sizeof(tBSPVertex), &m_pVerts[0].vPosition, GL_STATIC_DRAW));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, 0));

    glBindBuffer(GL_ARRAY_BUFFER, 0);
}

and then render like this?

//-----------------------------------------------------------------------------
//
// Actually draw the BSP face
void bsp_drawFace(tBSPFace *ptrFace)
//-----------------------------------------------------------------------------
{
    GL_ASSERT(glBindVertexArray(bspVAO_ID));

    GL_ASSERT(glUseProgram(shaderProgram[SHADER_GEOMETRY_PASS].programID));

    wrapglBindTexture(GL_TEXTURE0, texturesLoaded[TEX_WALL].texID);
    GL_ASSERT(glUniform1i(shaderProgram[SHADER_GEOMETRY_PASS].inTextureUnit, 0));

    GL_ASSERT(glUniformMatrix4fv(glGetUniformLocation(shaderProgram[SHADER_GEOMETRY_PASS].programID, "u_modelMat"), 1, false, glm::value_ptr(modelMatrix) ));

    GL_ASSERT(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementArrayID));
    GL_ASSERT(glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(int) * m_numOfMeshIndexes, &m_pMeshIndex[0], GL_STATIC_DRAW));

    GL_ASSERT(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_VERT));

    // Position
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[SHADER_GEOMETRY_PASS].inVertsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[SHADER_GEOMETRY_PASS].inVertsID, 3, GL_FLOAT, GL_FALSE, sizeof(tBSPVertex), (void*)(0)));

    // Texture coords
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[SHADER_GEOMETRY_PASS].inTextureCoordsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[SHADER_GEOMETRY_PASS].inTextureCoordsID, 2, GL_FLOAT, GL_FALSE, sizeof(tBSPVertex), (void*)(sizeof(float) * 3)));

    // Lightmap coords
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[SHADER_GEOMETRY_PASS].inTextureCoordsID_1));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[SHADER_GEOMETRY_PASS].inTextureCoordsID_1, 2, GL_FLOAT, GL_FALSE, sizeof(tBSPVertex), (void*)(sizeof(float) * 3) + (sizeof(float) * 2)));

    // Normals
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[SHADER_GEOMETRY_PASS].inNormalsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[SHADER_GEOMETRY_PASS].inNormalsID, 3, GL_FLOAT, GL_FALSE, sizeof(tBSPVertex), (void*)(sizeof(float) * 3) + (sizeof(float) * 4)));

    GL_ASSERT(glDrawElements(GL_TRIANGLES, ptrFace->numOfVerts, GL_UNSIGNED_INT, ptrFace->startVertIndex));

//    GL_ASSERT(glDrawElements(GL_TRIANGLES, ptrFace->numMeshVerts, GL_UNSIGNED_INT, &m_pMeshIndex[ptrFace->meshVertIndex]));

}

with tBSPVertex looking like this - I'm ignoring the colors for the moment

struct tBSPVertex
{
    glm::vec3 vPosition;			// (x, y, z) position.
    glm::vec2 vTextureCoord;		// (u, v) texture coordinate
    glm::vec2 vLightmapCoord;	    // (u, v) lightmap coordinate
    glm::vec3 vNormal;			    // (x, y, z) normal vector
    byte color[4];				    // RGBA color for the vertex
};

Won't the last parameter to glDrawElements need to be the index into the tBSPVertex array?  If it's 0, then won't it always be drawing just the first triangle?

 

Thanks

Share this post


Link to post
Share on other sites

Thanks - still nothing on the screen

 

If I am using an ELEMENT_ARRAY_BUFFER like so:

 

m_pMeshIndex is an int array read in from the BSP file.

    GL_ASSERT(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementArrayID));
    GL_CHECK(glBufferData(GL_ELEMENT_ARRAY_BUFFER, m_numOfMeshIndexes * sizeof(int), &m_pMeshIndex[0], GL_STATIC_DRAW));

Do I still need to reference the array holding the mesh indexes - like so??

    GL_ASSERT(glDrawElements(GL_TRIANGLES, ptrFace->numOfVerts, GL_UNSIGNED_INT, &m_pMeshIndex[ptrFace->startVertIndex]));

Or should I draw like this because glDrawElement will look up the index??

    GL_ASSERT(glDrawElements(GL_TRIANGLES, ptrFace->numOfVerts, GL_UNSIGNED_INT, ptrFace->startVertIndex));

Cheers

Edited by Droid_999

Share this post


Link to post
Share on other sites

The last one should be correct when you're using buffers, the data is already sent to the GPU and it just tells the offset. I'm not really sure, but I think you have to multiply it by the size of unsigned int though?

Share this post


Link to post
Share on other sites

Hi

 

I found this doc describing the quake 3 specs, and a suggestion on how to render the faces:

const Face& curFace = face[visibleFace[f]];
static const stride = sizeof(Vertex); // BSP Vertex, not float[3]
const int offset    = face.firstVertex;

glVertexPointer(3, GL_FLOAT, stride, &(vertex[offset].position));

glClientActiveTextureARB(GL_TEXTURE0_ARB);
glTexCoordPointer(2, GL_FLOAT, stride, &(vertex[offset].textureCoord));

glClientActiveTextureARB(GL_TEXTURE1_ARB);
glTexCoordPointer(2, GL_FLOAT, stride, &(vertex[offset].lightmapCoord));

glDrawElements(GL_TRIANGLES, curFace.meshVertexesCount,
   GL_UNSIGNED_INT, &meshVertex[curFace.firstMeshVertex]);

This is using non-core GL.

 

How do I replicate that using modern core GL ??

 

At the moment I have this:

//-----------------------------------------------------------------------------
//
// Actually draw the BSP face
void bsp_drawFace(tBSPFace *ptrFace, int whichShader)
//-----------------------------------------------------------------------------
{
    int stride = sizeof(tBSPVertex); // BSP Vertex, not float[3]

//    GL_ASSERT(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementArrayID));
//    GL_CHECK(glBufferData(GL_ELEMENT_ARRAY_BUFFER, m_numOfMeshIndexes * sizeof(int), &m_pMeshIndex, GL_STATIC_DRAW));

//    GL_ASSERT(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_VERT));

    // Position
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[whichShader].inVertsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[whichShader].inVertsID, 3, GL_FLOAT, false, stride, BUFFER_OFFSET(0)));

    // Texture coords
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[whichShader].inTextureCoordsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[whichShader].inTextureCoordsID, 2, GL_FLOAT, false, stride, (void*)(sizeof(glm::vec3))));

    // Lightmap coords
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[whichShader].inTextureCoordsID_1));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[whichShader].inTextureCoordsID_1, 2, GL_FLOAT, false, stride, (void*)sizeof(glm::vec3) + sizeof(glm::vec2)));

    // Normals
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[whichShader].inNormalsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[whichShader].inNormalsID, 3, GL_FLOAT, false, stride, (void*)sizeof(glm::vec3) + (sizeof(glm::vec2) * 4)));

    glDrawElements(GL_TRIANGLES, ptrFace->numMeshVerts, GL_UNSIGNED_INT, &m_pMeshIndex[ptrFace->meshVertIndex]);

    bsp_debugBSPData(ptrFace);
}

I have also tried rendering using an ELEMENT_BUFFER, but I don't get anything on the screen, at the moment, I get flashing red triangles, seemingly centred at 0,0,0.

 

I can debug a face using this - with double indexes it seems:

// Display BSP data
void bsp_debugBSPData(tBSPFace *ptrFace)
//-----------------------------------------------------------------------------
{
    static bool debugDone = false;

    if (false == debugDone)
    {
        con_print(CON_INFO, true, "Num verts mesh verts [ %i ] Num, Triangles [ %i ]", ptrFace->numMeshVerts, ptrFace->numMeshVerts / 3);

        for (int i = 0; i != ptrFace->numMeshVerts; i++)
        {
            con_print(CON_INFO, true, "Face meshVertIndex [ %i ] meshVertIndex [ %i ]", ptrFace->meshVertIndex + i, m_pMeshIndex[ptrFace->meshVertIndex + i]);
            con_print(CON_INFO, true, "VertexPos [ %i ] [ %3.3f %3.3f %3.3f ]", m_pMeshIndex[ptrFace->meshVertIndex + i],
                      m_pVerts[m_pMeshIndex[ptrFace->meshVertIndex + i]].vPosition.x,
                      m_pVerts[m_pMeshIndex[ptrFace->meshVertIndex + i]].vPosition.y,
                      m_pVerts[m_pMeshIndex[ptrFace->meshVertIndex + i]].vPosition.z );
        }
        debugDone = true;
    }
}

Is it even possible to replicate the above non-core code using modern GL ??

 

Thanks

 

Share this post


Link to post
Share on other sites

Hmm, I'm not really sure about this, but I think you can use glDrawElementsBaseVertex instead of glDrawElements to do it like the example shows, just pass face.firstVertex in the last parameter? Btw, the last multiplication in normal attribute's offset seems to be wrong.

Share this post


Link to post
Share on other sites

I can now render the BSP data - but only by uploading a face at a time each frame - not the best !!

 

Here's the routine - it's split into two, the first #define does it the slow way, by pulling out the vertex information for that frame, and uploading to the card.  This works ok.  The second part should be using the information that is loaded onto the card once at load time - but it doesn't render anything.


//-----------------------------------------------------------------------------
//
// Actually draw the BSP face
void bsp_drawFace(tBSPFace *ptrFace, int whichShader)
//-----------------------------------------------------------------------------
{
//    #define SLOW_WAY

    #ifdef SLOW_WAY
    typedef struct
    {
        glm::vec3   position;
        glm::vec2   texCoords;
        glm::vec3   normals;
    } _myVertex;

    _myVertex myVertex[40];

    int         indexes[40];
    int         i = 0;
    GLuint      vao;
    GLuint      vbo_ID;

    int stride = sizeof(_myVertex);

    for (i = 0; i != ptrFace->numMeshVerts; i++)
    {
        indexes[i] = m_pMeshIndex[ptrFace->startMeshVertIndex + i];

        myVertex[i].position =  m_pVerts[ptrFace->startVertIndex + indexes[i]].vPosition;
        myVertex[i].texCoords = m_pVerts[ptrFace->startVertIndex + indexes[i]].vTextureCoord;
        myVertex[i].normals =   m_pVerts[ptrFace->startVertIndex + indexes[i]].vNormal;
    }

   // create the VAO
    GL_ASSERT(glGenVertexArrays(1, &vao));
    GL_CHECK(glBindVertexArray(vao));
    //
    // create buffers for our vertex data
    GL_ASSERT(glGenBuffers(1, &vbo_ID));

    GL_CHECK(glUseProgram(shaderProgram[whichShader].programID));

    GL_ASSERT(glBindBuffer(GL_ARRAY_BUFFER, vbo_ID));
    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, ptrFace->numMeshVerts * sizeof(_myVertex), myVertex, GL_STATIC_DRAW));
    //
    // position
    GL_CHECK(glEnableVertexAttribArray(shaderProgram[whichShader].inVertsID));
    GL_CHECK(glVertexAttribPointer(shaderProgram[whichShader].inVertsID,3, GL_FLOAT,GL_FALSE, stride, offsetof(_myVertex, position) ));
    //
    // Textur coordinates
    glEnableVertexAttribArray(shaderProgram[whichShader].inTextureCoordsID);
    glVertexAttribPointer(shaderProgram[whichShader].inTextureCoordsID, 2, GL_FLOAT, false, stride, offsetof(_myVertex, texCoords));
    //
    // Normals
    glEnableVertexAttribArray(shaderProgram[whichShader].inNormalsID);
    glVertexAttribPointer(shaderProgram[whichShader].inNormalsID, 3, GL_FLOAT, false, stride, offsetof(_myVertex, normals));
    //
    // unbind the VAO
    glBindVertexArray(0);

//
// -------------
//


    GL_CHECK(glUniformMatrix4fv(shaderProgram[whichShader].modelMat, 1, false, glm::value_ptr(modelMatrix)));
    GL_CHECK(glUniformMatrix4fv(shaderProgram[whichShader].viewProjectionMat, 1, false, glm::value_ptr(projMatrix * viewMatrix)));

    GL_CHECK(glBindVertexArray(vao));
    //
    // Enable attribute to hold vertex information
    GL_CHECK(glEnableVertexAttribArray(shaderProgram[whichShader].inVertsID));
    GL_CHECK(glEnableVertexAttribArray(shaderProgram[whichShader].inTextureCoordsID));
    GL_CHECK(glEnableVertexAttribArray(shaderProgram[whichShader].inNormalsID));

//    GL_CHECK(glDrawElements(GL_TRIANGLES, ptrFace->numMeshVerts, GL_UNSIGNED_INT, 0));

    glDrawArrays(GL_TRIANGLES, 0, ptrFace->numMeshVerts);

    glUseProgram(0);
    glBindVertexArray(0);

    #else if

    int stride = sizeof(tBSPVertex); // BSP Vertex, not float[3]

    GL_CHECK(glUseProgram(shaderProgram[whichShader].programID));

    GL_CHECK(glBindVertexArray(bspVAO_ID));

    GL_CHECK(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementArrayID));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_VERT));

    // Position
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[whichShader].inVertsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[whichShader].inVertsID, 3, GL_FLOAT, false, stride, (offsetof(tBSPVertex, vPosition))));

    // Texture coords
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[whichShader].inTextureCoordsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[whichShader].inTextureCoordsID, 2, GL_FLOAT, false, stride, offsetof(tBSPVertex, vTextureCoord)));

    // Lightmap coords - not used in shader yet
//    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[whichShader].inTextureCoordsID_1));
//    GL_ASSERT(glVertexAttribPointer(shaderProgram[whichShader].inTextureCoordsID_1, 2, GL_FLOAT, false, stride, offsetof(tBSPVertex, vLightmapCoord)));

    // Normals
    GL_ASSERT(glEnableVertexAttribArray(shaderProgram[whichShader].inNormalsID));
    GL_ASSERT(glVertexAttribPointer(shaderProgram[whichShader].inNormalsID, 3, GL_FLOAT, false, stride, offsetof(tBSPVertex, vNormal)));

    GL_CHECK(glUniformMatrix4fv(shaderProgram[whichShader].modelMat, 1, false, glm::value_ptr(modelMatrix)));
    GL_CHECK(glUniformMatrix4fv(shaderProgram[whichShader].viewProjectionMat, 1, false, glm::value_ptr(projMatrix * viewMatrix)));

    GL_ASSERT(glDrawElementsBaseVertex(GL_TRIANGLES, ptrFace->numMeshVerts, GL_UNSIGNED_INT, (const GLvoid *)ptrFace->startMeshVertIndex, ptrFace->startVertIndex));

    glBindBuffer(GL_ARRAY_BUFFER, 0);

    gl_getAllGLErrors(glGetError(), __FILE__, __LINE__);

    #endif
}

Here's where it's uploaded at load time


//-----------------------------------------------------------------------------
//
// Upload vertex arrays to GPU
bool bsp_uploadBspToGPU()
//-----------------------------------------------------------------------------
{
    //
    // Store model and all meshes in one VAO
    GL_CHECK(glGenVertexArrays(1, &bspVAO_ID));
    GL_CHECK(glBindVertexArray(bspVAO_ID));

    GL_CHECK(glGenBuffers(1, &elementArrayID));
    GL_CHECK(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, elementArrayID));
    GL_CHECK(glBufferData(GL_ELEMENT_ARRAY_BUFFER, m_numOfMeshIndexes * sizeof(int), &m_pMeshIndex, GL_STATIC_DRAW));
    GL_CHECK(glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0));
    //
    // Load vertices information into GPU
    GL_CHECK(glGenBuffers(1, &bspVBO_VERT));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, bspVBO_VERT));
    GL_CHECK(glBufferData(GL_ARRAY_BUFFER, m_numOfVerts * sizeof(tBSPVertex), &m_pVerts, GL_STATIC_DRAW));
    GL_CHECK(glBindBuffer(GL_ARRAY_BUFFER, 0));

    GL_CHECK(glBindBuffer(GL_VERTEX_ARRAY, 0));
}

Can anyone see why the second way ( using glDrawElementsBaseVertex ) wouldn't work.

 

Thanks.

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement