• Advertisement
Sign in to follow this  

OpenGL Render indexed data from Q3 BSP

This topic is 1054 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
  • Advertisement
  • Popular Now

  • Advertisement
  • Similar Content

    • By Balma Alparisi
      i got error 1282 in my code.
      sf::ContextSettings settings; settings.majorVersion = 4; settings.minorVersion = 5; settings.attributeFlags = settings.Core; sf::Window window; window.create(sf::VideoMode(1600, 900), "Texture Unit Rectangle", sf::Style::Close, settings); window.setActive(true); window.setVerticalSyncEnabled(true); glewInit(); GLuint shaderProgram = createShaderProgram("FX/Rectangle.vss", "FX/Rectangle.fss"); float vertex[] = { -0.5f,0.5f,0.0f, 0.0f,0.0f, -0.5f,-0.5f,0.0f, 0.0f,1.0f, 0.5f,0.5f,0.0f, 1.0f,0.0f, 0.5,-0.5f,0.0f, 1.0f,1.0f, }; GLuint indices[] = { 0,1,2, 1,2,3, }; GLuint vao; glGenVertexArrays(1, &vao); glBindVertexArray(vao); GLuint vbo; glGenBuffers(1, &vbo); glBindBuffer(GL_ARRAY_BUFFER, vbo); glBufferData(GL_ARRAY_BUFFER, sizeof(vertex), vertex, GL_STATIC_DRAW); GLuint ebo; glGenBuffers(1, &ebo); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, ebo); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices,GL_STATIC_DRAW); glVertexAttribPointer(0, 3, GL_FLOAT, false, sizeof(float) * 5, (void*)0); glEnableVertexAttribArray(0); glVertexAttribPointer(1, 2, GL_FLOAT, false, sizeof(float) * 5, (void*)(sizeof(float) * 3)); glEnableVertexAttribArray(1); GLuint texture[2]; glGenTextures(2, texture); glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texture[0]); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); sf::Image* imageOne = new sf::Image; bool isImageOneLoaded = imageOne->loadFromFile("Texture/container.jpg"); if (isImageOneLoaded) { glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageOne->getSize().x, imageOne->getSize().y, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageOne->getPixelsPtr()); glGenerateMipmap(GL_TEXTURE_2D); } delete imageOne; glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, texture[1]); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); sf::Image* imageTwo = new sf::Image; bool isImageTwoLoaded = imageTwo->loadFromFile("Texture/awesomeface.png"); if (isImageTwoLoaded) { glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, imageTwo->getSize().x, imageTwo->getSize().y, 0, GL_RGBA, GL_UNSIGNED_BYTE, imageTwo->getPixelsPtr()); glGenerateMipmap(GL_TEXTURE_2D); } delete imageTwo; glUniform1i(glGetUniformLocation(shaderProgram, "inTextureOne"), 0); glUniform1i(glGetUniformLocation(shaderProgram, "inTextureTwo"), 1); GLenum error = glGetError(); std::cout << error << std::endl; sf::Event event; bool isRunning = true; while (isRunning) { while (window.pollEvent(event)) { if (event.type == event.Closed) { isRunning = false; } } glClear(GL_COLOR_BUFFER_BIT); if (isImageOneLoaded && isImageTwoLoaded) { glActiveTexture(GL_TEXTURE0); glBindTexture(GL_TEXTURE_2D, texture[0]); glActiveTexture(GL_TEXTURE1); glBindTexture(GL_TEXTURE_2D, texture[1]); glUseProgram(shaderProgram); } glBindVertexArray(vao); glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, nullptr); glBindVertexArray(0); window.display(); } glDeleteVertexArrays(1, &vao); glDeleteBuffers(1, &vbo); glDeleteBuffers(1, &ebo); glDeleteProgram(shaderProgram); glDeleteTextures(2,texture); return 0; } and this is the vertex shader
      #version 450 core layout(location=0) in vec3 inPos; layout(location=1) in vec2 inTexCoord; out vec2 TexCoord; void main() { gl_Position=vec4(inPos,1.0); TexCoord=inTexCoord; } and the fragment shader
      #version 450 core in vec2 TexCoord; uniform sampler2D inTextureOne; uniform sampler2D inTextureTwo; out vec4 FragmentColor; void main() { FragmentColor=mix(texture(inTextureOne,TexCoord),texture(inTextureTwo,TexCoord),0.2); } I was expecting awesomeface.png on top of container.jpg

    • By khawk
      We've just released all of the source code for the NeHe OpenGL lessons on our Github page at https://github.com/gamedev-net/nehe-opengl. code - 43 total platforms, configurations, and languages are included.
      Now operated by GameDev.net, NeHe is located at http://nehe.gamedev.net where it has been a valuable resource for developers wanting to learn OpenGL and graphics programming.

      View full story
    • By TheChubu
      The Khronos™ Group, an open consortium of leading hardware and software companies, announces from the SIGGRAPH 2017 Conference the immediate public availability of the OpenGL® 4.6 specification. OpenGL 4.6 integrates the functionality of numerous ARB and EXT extensions created by Khronos members AMD, Intel, and NVIDIA into core, including the capability to ingest SPIR-V™ shaders.
      SPIR-V is a Khronos-defined standard intermediate language for parallel compute and graphics, which enables content creators to simplify their shader authoring and management pipelines while providing significant source shading language flexibility. OpenGL 4.6 adds support for ingesting SPIR-V shaders to the core specification, guaranteeing that SPIR-V shaders will be widely supported by OpenGL implementations.
      OpenGL 4.6 adds the functionality of these ARB extensions to OpenGL’s core specification:
      GL_ARB_gl_spirv and GL_ARB_spirv_extensions to standardize SPIR-V support for OpenGL GL_ARB_indirect_parameters and GL_ARB_shader_draw_parameters for reducing the CPU overhead associated with rendering batches of geometry GL_ARB_pipeline_statistics_query and GL_ARB_transform_feedback_overflow_querystandardize OpenGL support for features available in Direct3D GL_ARB_texture_filter_anisotropic (based on GL_EXT_texture_filter_anisotropic) brings previously IP encumbered functionality into OpenGL to improve the visual quality of textured scenes GL_ARB_polygon_offset_clamp (based on GL_EXT_polygon_offset_clamp) suppresses a common visual artifact known as a “light leak” associated with rendering shadows GL_ARB_shader_atomic_counter_ops and GL_ARB_shader_group_vote add shader intrinsics supported by all desktop vendors to improve functionality and performance GL_KHR_no_error reduces driver overhead by allowing the application to indicate that it expects error-free operation so errors need not be generated In addition to the above features being added to OpenGL 4.6, the following are being released as extensions:
      GL_KHR_parallel_shader_compile allows applications to launch multiple shader compile threads to improve shader compile throughput WGL_ARB_create_context_no_error and GXL_ARB_create_context_no_error allow no error contexts to be created with WGL or GLX that support the GL_KHR_no_error extension “I’m proud to announce OpenGL 4.6 as the most feature-rich version of OpenGL yet. We've brought together the most popular, widely-supported extensions into a new core specification to give OpenGL developers and end users an improved baseline feature set. This includes resolving previous intellectual property roadblocks to bringing anisotropic texture filtering and polygon offset clamping into the core specification to enable widespread implementation and usage,” said Piers Daniell, chair of the OpenGL Working Group at Khronos. “The OpenGL working group will continue to respond to market needs and work with GPU vendors to ensure OpenGL remains a viable and evolving graphics API for all its customers and users across many vital industries.“
      The OpenGL 4.6 specification can be found at https://khronos.org/registry/OpenGL/index_gl.php. The GLSL to SPIR-V compiler glslang has been updated with GLSL 4.60 support, and can be found at https://github.com/KhronosGroup/glslang.
      Sophisticated graphics applications will also benefit from a set of newly released extensions for both OpenGL and OpenGL ES to enable interoperability with Vulkan and Direct3D. These extensions are named:
      GL_EXT_memory_object GL_EXT_memory_object_fd GL_EXT_memory_object_win32 GL_EXT_semaphore GL_EXT_semaphore_fd GL_EXT_semaphore_win32 GL_EXT_win32_keyed_mutex They can be found at: https://khronos.org/registry/OpenGL/index_gl.php
      Industry Support for OpenGL 4.6
      “With OpenGL 4.6 our customers have an improved set of core features available on our full range of OpenGL 4.x capable GPUs. These features provide improved rendering quality, performance and functionality. As the graphics industry’s most popular API, we fully support OpenGL and will continue to work closely with the Khronos Group on the development of new OpenGL specifications and extensions for our customers. NVIDIA has released beta OpenGL 4.6 drivers today at https://developer.nvidia.com/opengl-driver so developers can use these new features right away,” said Bob Pette, vice president, Professional Graphics at NVIDIA.
      "OpenGL 4.6 will be the first OpenGL release where conformant open source implementations based on the Mesa project will be deliverable in a reasonable timeframe after release. The open sourcing of the OpenGL conformance test suite and ongoing work between Khronos and X.org will also allow for non-vendor led open source implementations to achieve conformance in the near future," said David Airlie, senior principal engineer at Red Hat, and developer on Mesa/X.org projects.

      View full story
    • By _OskaR
      Hi,
      I have an OpenGL application but without possibility to wite own shaders.
      I need to perform small VS modification - is possible to do it in an alternative way? Do we have apps or driver modifictions which will catch the shader sent to GPU and override it?
    • By xhcao
      Does sync be needed to read texture content after access texture image in compute shader?
      My simple code is as below,
      glUseProgram(program.get());
      glBindImageTexture(0, texture[0], 0, GL_FALSE, 3, GL_READ_ONLY, GL_R32UI);
      glBindImageTexture(1, texture[1], 0, GL_FALSE, 4, GL_WRITE_ONLY, GL_R32UI);
      glDispatchCompute(1, 1, 1);
      // Does sync be needed here?
      glUseProgram(0);
      glBindFramebuffer(GL_READ_FRAMEBUFFER, framebuffer);
      glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                                     GL_TEXTURE_CUBE_MAP_POSITIVE_X + face, texture[1], 0);
      glReadPixels(0, 0, kWidth, kHeight, GL_RED_INTEGER, GL_UNSIGNED_INT, outputValues);
       
      Compute shader is very simple, imageLoad content from texture[0], and imageStore content to texture[1]. Does need to sync after dispatchCompute?
  • Advertisement