I'm trying to implement deferred rendering within an engine I'm developing as a personal learning, and I cannot get to understand what I'm doing wrong when it comes to render all the textures in the GBuffer to check if the implementation is okay.
The thing is that I currently have a framebuffer with 3 color attachments for the different textures of the GBuffer (color, normal and position), which I initialize as follows:
glCreateFramebuffers(1, &id);
glBindFramebuffer(GL_FRAMEBUFFER, id);
std::vector<uint> textures;
textures.resize(3);
glCreateTextures(GL_TEXTURE_2D, 3, textures.data());
for(size_t i = 0; i < 3; ++i)
{
glBindTexture(GL_TEXTURE_2D, textures[i]);
if(i == 0) // For Color Buffer
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);
else
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA16F, width, height, 0, GL_RGBA, GL_FLOAT, nullptr);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + i, GL_TEXTURE_2D, textures[i], 0);
}
GLenum color_buffers[3] = { GL_COLOR_ATTACHMENT0, GL_COLOR_ATTACHMENT1, GL_COLOR_ATTACHMENT2 };
glDrawBuffers((GLsizei)textures.size(), color_buffers);
uint depth_texture;
glCreateTextures(GL_TEXTURE_2D, 1, &depth_texture);
glBindTexture(GL_TEXTURE_2D, depth_texture);
glTexStorage2D(GL_TEXTURE_2D, 1, GL_DEPTH24_STENCIL8, width, height);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_TEXTURE_2D, depth_texture, 0);
bool fbo_status = glCheckFramebufferStatus(GL_FRAMEBUFFER) == GL_FRAMEBUFFER_COMPLETE;
ASSERT(fbo_status, "Framebuffer Incompleted!");
glBindFramebuffer(GL_FRAMEBUFFER, 0);
This is not reporting any errors and it seems to work since the framebuffer of the forward renderer renders properly. Then, when rendering, I run the next code after binding the framebuffer and clearing the color and depth buffers:
camera_buffer->Bind();
camera_buffer->SetData("ViewProjection", glm::value_ptr(viewproj_mat));
camera_buffer->SetData("CamPosition", glm::value_ptr(glm::vec4(view_position, 0.0f)));
camera_buffer->Unbind();
for(Entity& entity : scene_entities)
{
shader->Bind();
Texture* texture = entity.GetTexture();
BindTexture(0, texture);
shader->SetUniformMat4("u_Model", entity.transform);
shader->SetUniformInt("u_Albedo", 0);
shader->SetUniformVec4("u_Material.AlbedoColor", entity->AlbedoColor);
shader->SetUniformFloat("u_Material.Smoothness", entity->Smoothness);
glBindVertexArray(entity.VertexArray);
glDrawElements(GL_TRIANGLES, entity.VertexArray.index_buffer.count, GL_UNSIGNED_INT, nullptr);
// Shader, VArray and Textures Unbindings
}
So with this code I manage to render the 3 textures created by using the ImGui::Image function, by switching the texture index between 0, 1 or 2 as the next:
ImGui::Image((ImTextureID)(fbo->textures[0]), viewport_size, ImVec2(0, 1), ImVec2(1, 0));
Now, the color texture (at index 0) works perfectly, as the next image shows:
But when rendering the normals and position textures (indexes 2 and 3), I have no result:
Does anybody sees what I'm doing wrong? Because I've been hours and hours with this and I cannot see it. I ran this on RenderDoc and I couldn't see anything wrong, the textures displayed in RenderDoc are the same than in the engine.
The vertex shader I use when rendering the entities is the next:
layout(location = 0) in vec3 a_Position;
layout(location = 1) in vec2 a_TexCoord;
layout(location = 2) in vec3 a_Normal;
out IBlock
{
vec2 TexCoord;
vec3 FragPos;
vec3 Normal;
} v_VertexData;
layout(std140, binding = 0) uniform ub_CameraData
{
mat4 ViewProjection;
vec3 CamPosition;
};
uniform mat4 u_ViewProjection = mat4(1.0);
uniform mat4 u_Model = mat4(1.0);
void main()
{
vec4 world_pos = u_Model * vec4(a_Position, 1.0);
v_VertexData.TexCoord = a_TexCoord;
v_VertexData.FragPos = world_pos.xyz;
v_VertexData.Normal = transpose(inverse(mat3(u_Model))) * a_Normal;
gl_Position = ViewProjection * u_Model * vec4(a_Position, 1.0);
}
And the fragment one is the next, they are both pretty simple:
layout(location = 0) out vec4 gBuff_Color;
layout(location = 1) out vec3 gBuff_Normal;
layout(location = 2) out vec3 gBuff_Position;
in IBlock
{
vec2 TexCoord;
vec3 FragPos;
vec3 Normal;
} v_VertexData;
struct Material
{
float Smoothness;
vec4 AlbedoColor;
};
uniform Material u_Material = Material(1.0, vec4(1.0));
uniform sampler2D u_Albedo, u_Normal;
void main()
{
gBuff_Color = texture(u_Albedo, v_VertexData.TexCoord) * u_Material.AlbedoColor;
gBuff_Normal = normalize(v_VertexData.Normal);
gBuff_Position = v_VertexData.FragPos;
}
It is not clear from the question what exactly might be happening here, as lots of GL states - both at the time the rendering to the gbuffer, and at that time the gbuffer texture is rendered for visualization - are just unknown. However, from the images given in the question, one can not conclude that the actual color output for attachments 1 and 2 is not working.
One issue which comes to mind is alpha blending. The color values processed by the per-fragment operations after the vertex shader are always working with RGBA values - although the value of the A channel only matters if you enabled blending and use a blend function which somehow depends on the source alpha.
If you declare a custom fragment shader output as float, vec2, vec3, the remaining components stay undefined (undefined value, not undefined behavior). This does not impose a problem unless some other operations you do depend on those values.
What we also have here is a GL_RGBA16F output format (which is the right choice, because none of the 3-component RGB formats are required as color-renderable by the spec).
What might happen here is either:
Alpha blending is already turned on during rendering into the g-buffer. The fragment shader's alpha output happens to be zero, so that it appears as 100% transparent and the contents of the texture are not changed.
Alpha blending is not used during rendering into the g-buffer, so the correct contents end up in the texture, the alpha channel just happens to end up with all zeros. Now the texture might be visualized with alpha blending enbaled, ending up in a 100% transparent view.
If it is the first option, turn off blending when rendering the into the g-buffer. It would not work with deferred shading anyway. You might still run into the second option then.
If this is the second option, there is no issue at all - the lighting passes which follow will read the data they need (and ultimately, you will want to put useful information into the alpha channel to not waste it and be able to reduce the number of attachments). It is just your visualization (which I assume is for debug purposed only) is wrong. You can try to fix the visualization.
As a side note: Storing the world space position in the G-Buffer is a huge waste of bandwidth. All you need to be able to reconstruct the world space position is the depth value and the inverse of your view and projection matrices. Also storing world space position in GL_RGB16F will very easily run into precision issues if you move your camera away from world space origin.
I can't get my textures to work, all the screen is black.
Here is my code for loading the images, I use lodepng:
std::vector<unsigned char> image;
unsigned int error = lodepng::decode(image, w, h, filename);
GLuint texture_id;
glGenTextures(1, &texture_id);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture_id);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, 4, w, h, 0, GL_RGBA, GL_UNSIGNED_BYTE, &image[0]);
glBindTexture(GL_TEXTURE_2D, 0);
For the rendering I do this:
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texture_id_from_above); //texture_id were checked, seemed fine
glUniform1i(shader_sampler_loc, GL_TEXTURE0);
and my frag shader(trimmed version) is basically doing this:
uniform sampler2D sampler;
void main(void) {
gl_FragColor = texture2D(sampler, uv_coord);
}
The UV-coordinates are fine, the vector from lodepng containes many elements and there is no error returned. To further pin the problem I tried this:
gl_FragColor = texture2D(sampler, uv_coord)*0.5 + vec4(1, 1, 1, 1)*0.5f
To see if the whole assignment is somehow skipped or the texture in fact black. As a result I still only get a black window. But by removing
glActiveTexture(GL_TEXTURE0); //x2, and
glUniform1i(sampler_loc, GL_TEXTURE0);
all my objects appear gray. I have no clue what is wrong.
BTW: it was working before moving to OpenGL 3.2 (had 2.1 before), and all images are ^2. I use CORE_PROFILE && FORWARD_COMPAT.
Vertex shader:
#version 150
//VBO vertex attributes
attribute vec3 pos;
attribute vec2 tex;
attribute vec3 normal;
varying vec2 uv_coord;
uniform mat4 mvp_mat;
void main(void) {
gl_Position = mvp_mat * vec4(pos, 1);
uv_coord = tex;
}
glUniform1i(shader_sampler_loc, GL_TEXTURE0);
. . . should be
glUniform1i(shader_sampler_loc, 0);
etc.
So I kind of solved it, by using OPENGL_COMPAT_PROFILE it works. Though I would really want to go full 3.2, and find which parts are deprecated...
EDIT:
In my case, I finally found the dumb error, I was using
glTexImage2D(GL_TEXTURE_2D, 0, 4, ... //instead of
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, ...
So I guess the with the old GL I was lucky, and with 3.2 the enum were changed?
As comments suggest try changing the following:
Vertex shader:
out instead of varying
Add layout(location = #) to your attributes and change attribute for in.
Make sure, number of locations match the code
Fragment shader: (Assuming since its not complete)
in instead of varying
Add layout(location = #) to your sampler uniform
For the code:
Change
glUniform1i(sampler_loc, GL_TEXTURE0)
to
glUniform1i(sampler_loc, 0)
I'm using the tutorials on http://arcsynthesis.org/gltut/ to learn OpenGL, it's required, I have to use it. Mostly I want to apply the textures from Tutorial 15 onto objects in tutorial 7 (world with UBO).
For now it seemed like the textures only work when mipmaps are turned on. This comes with a downside: The only mipmap used is the one with an index of zero, and that's the 1 colored 1x1 pixel one. I tried setting the minimum level of a mipmap higher or turning off mipmaps entirely, but even that doesn't fix thing, because then everything turns pitch black. Now I'll list the most important parts of my program
EDIT: I guess I'll add more details...
The vertex shader has something like this:
#version 330
layout(location = 0) in vec4 position;
layout(location = 1) in vec4 color;
layout(location = 2) in vec3 normal;
//Added these later
layout(location = 5) in vec2 texCoord;
out vec2 colorCoord;
smooth out vec4 interpColor;
out vec3 vertexNormal;
out vec3 modelSpacePosition;
out vec3 cameraSpacePosition;
uniform mat4 worldToCameraMatrix;
uniform mat4 modelToWorldMatrix;
uniform mat3 normalModelToCameraMatrix;
uniform vec3 dirToLight;
uniform vec4 lightIntensity;
uniform vec4 ambientIntensity;
uniform vec4 baseColor;
uniform mat4 cameraToClipMatrix;
void main()
{
vertexNormal = normal;
vec3 normCamSpace = normalize(normalModelToCameraMatrix * vertexNormal);
cameraSpacePosition = normCamSpace;
float cosAngIncidence = dot(normCamSpace, dirToLight);
cosAngIncidence = clamp(cosAngIncidence, 0, 1);
modelSpacePosition.x = position.x;
modelSpacePosition.y = position.y;
modelSpacePosition.z = position.z;
vec4 temp = modelToWorldMatrix * position;
temp = worldToCameraMatrix * temp;
gl_Position = cameraToClipMatrix * temp;
interpColor = ((lightIntensity * cosAngIncidence) + (ambientIntensity)) * baseColor;
colorCoord= texCoord ;
}
The fragment shader like this:
#version 330
in vec3 vertexNormal;
in vec3 modelSpacePosition;
smooth in vec4 interpColor;
uniform vec3 modelSpaceLightPos;
uniform vec4 lightIntensity2;
uniform vec4 ambientIntensity2;
out vec4 outputColor;
//Added later
in vec2 colorCoord;
uniform sampler2D colorTexture;
void main()
{
vec3 lightDir2 = normalize(modelSpacePosition - modelSpaceLightPos);
float cosAngIncidence2 = dot(normalize(vertexNormal), lightDir2);
cosAngIncidence2 = clamp(cosAngIncidence2, 0, 1);
float light2DistanceSqr = dot(modelSpacePosition - modelSpaceLightPos, modelSpacePosition - modelSpaceLightPos);
//added
vec4 texture2 = texture(colorTexture, colorCoord);
outputColor = ((ambientIntensity2 + (interpColor*2))/4) +
((((interpColor) * lightIntensity2/200 * cosAngIncidence2) + (ambientIntensity2* interpColor ))
/( ( sqrt(light2DistanceSqr) + light2DistanceSqr)/200 ));
//No outputColor for texture testing
outputColor = texture2 ;
}
}
Those were both shaders. And here are the parts added to the .cpp:
#include <glimg/glimg.h>
#include "../framework/directories.h"
[...]
const int g_colorTexUnit = 0;
GLuint g_checkerTexture = 0;
And here's the loader for the texture:
void LoadCheckerTexture()
{
try
{
std::string filename(LOCAL_FILE_DIR);
filename += "checker.dds";
std::auto_ptr<glimg::ImageSet>
pImageSet(glimg::loaders::dds::LoadFromFile(filename.c_str()));
glGenTextures(1, &g_checkerTexture);
glBindTexture(GL_TEXTURE_2D, g_checkerTexture);
glimg::SingleImage image = pImageSet->GetImage(0, 0, 0);
glimg::Dimensions dims = image.GetDimensions();
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, dims.width, dims.height, 0, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, image.GetImageData());
glBindTexture(GL_TEXTURE_2D, 0);
}
catch(std::exception &e)
{
printf("%s\n", e.what());
throw;
}
}
Naturally I've got this in void init():
LoadCheckerTexture();
And then when rendering the object:
glActiveTexture(GL_TEXTURE0 + g_colorTexUnit);
glBindTexture(GL_TEXTURE_2D,g_checkerTexture);
g_pLeftMesh->Render();
glBindSampler(g_colorTexUnit, 0);
glBindTexture(GL_TEXTURE_2D, 0);
With all of this, I get put pitch black for everything, however when I change the outputColor equation into "texture + outputColor;", everything looks normal. I have no idea what I'm doing wrong here. A friend tried to help me, we removed some unnecessairy stuff, but we got nothing running.
Ok guys, I've worked on this whole thing, and did manage to somehow get it running. First off I had to add samplers:
GLuint g_samplers;
//Add Later
void CreateSamplers()
{
glGenSamplers(1, &g_samplers);
glSamplerParameteri(g_samplers, GL_TEXTURE_WRAP_S, GL_REPEAT);
glSamplerParameteri(g_samplers, GL_TEXTURE_WRAP_T, GL_REPEAT);
//Linear mipmap Nearest
glSamplerParameteri(g_samplers, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glSamplerParameteri(g_samplers, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
}
I also added this to the file thing:
glimg::OpenGLPixelTransferParams xfer = glimg::GetUploadFormatType(pImageSet->GetFormat(), 0);
glimg::SingleImage image = pImageSet->GetImage(0, 0, 0);
glimg::Dimensions dims = image.GetDimensions();
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, dims.width, dims.height, 0,
xfer.format, xfer.type, image.GetImageData());
The xfer variable does get the format and type adjusted to the dds.
Also the render code got turned into this:
//Added necessary
glActiveTexture(GL_TEXTURE0 + g_colorTexUnit);
glBindTexture(GL_TEXTURE_2D,g_checkerTexture);
glBindSampler(g_colorTexUnit, g_samplers);
g_pLeftMesh->Render();
glBindSampler(g_colorTexUnit, 0);
glBindTexture(GL_TEXTURE_2D, 0);
And of course at the end of init() I needed to add the CreateSamplers thing:
//Added this later
LoadCheckerTexture();
CreateSamplers();
I'm sorry for all the trouble with all this, but guess OpenGL really is just this confusing and it was just dumb luck that I got it right. Just posting this so that people know
Your fail to add textures may be caused by:
Have you add texture coordinates to objects? (this is the most probable cause, because you are adding textures to non textured tutorial), add textures to VAO.
Did you add uniform textureunit (Sampler2D)? (it must be uniform, else texturing will not work properly)
Is your texture loaded,binded,enabled (GL_TEXTURE_2D) ?
Is your active texture unit - 0? if not change layout/multitexture coords or set active texture 0
This two codes are simple texturing shaders (texture unit 0) no special things (like light,blend,bump,...):
tm_l2g is transformation local obj space -> world space (Modelview)
tm_g2s is transformation world space -> screen space (Projection)
pos are vertex coordinates
txt are texture coordinates
col are colors
Do not forget to change uniform names and layout locations to yours.
Vertex:
//------------------------------------------------------------------
#version 420 core
//------------------------------------------------------------------
uniform mat4x4 tm_l2g;
uniform mat4x4 tm_g2s;
layout(location=0) in vec3 pos;
layout(location=1) in vec4 col;
layout(location=2) in vec2 txr;
out smooth vec4 pixel_col;
out smooth vec2 pixel_txr;
//------------------------------------------------------------------
void main(void)
{
vec4 p;
p.xyz=pos;
p.w=1.0;
p=tm_l2g*p;
p=tm_g2s*p;
gl_Position=p;
pixel_col=col;
pixel_txr=txr;
}
//------------------------------------------------------------------
fragment:
//------------------------------------------------------------------
#version 420 core
//------------------------------------------------------------------
in smooth vec4 pixel_col;
in smooth vec2 pixel_txr;
uniform sampler2D txr_texture0;
out layout(location=0) vec4 frag_col;
//------------------------------------------------------------------
void main(void)
{
vec4 col;
col=texture(txr_texture0,pixel_txr.st);
frag_col=col*pixel_col;
}
//------------------------------------------------------------------
[edit1] CPU old style OpenGL render code (initializations are not included its only render code they can be found here)
//------------------------------------------------------------------
// set modelview,projection,textures,bind GLSL programs...
GLfloat a=10.0,z=0.0;
glColor3f(1.0,1.0,1.0);
glBegin(GL_QUADS);
// textured quad
glTexCoord2f(0.0,0.0); glVertex3f(-a,-a,z);
glTexCoord2f(0.0,1.0); glVertex3f(-a,+a,z);
glTexCoord2f(1.0,1.0); glVertex3f(+a,+a,z);
glTexCoord2f(1.0,0.0); glVertex3f(+a,-a,z);
// reverse order quad to be shore that at least one passes by CULL_FACE
glTexCoord2f(1.0,0.0); glVertex3f(+a,-a,z);
glTexCoord2f(1.0,1.0); glVertex3f(+a,+a,z);
glTexCoord2f(0.0,1.0); glVertex3f(-a,+a,z);
glTexCoord2f(0.0,0.0); glVertex3f(-a,-a,z);
glEnd();
//------------------------------------------------------------------
[edit2] ok here goes VAO/VBO render code,...
//------------------------------------------------------------------------------
// enum of VBO locations (it is also your layout location) I use enums for simple in code changes
enum _vbo_enum
{
_vbo_pos=0, // glVertex
_vbo_col, // glColor
_vbo_tan, // glNormal
_vbo_unused0, // unused (at least i dont see anything at this location in your code)
_vbo_unused1, // unused (at least i dont see anything at this location in your code)
_vbo_txr, // glTexCoord
_vbos
};
//------------------------------------------------------------------------------
// 'global' names and size for OpenGL mesh in VAO/VBO ... similar ot texture names/handles
GLuint vao[1],vbo[_vbos],num_pnt=0;
//------------------------------------------------------------------------------
void VAO_init_cube() // call this before VAO use,...but after OpenGL init !
{
//[1] first you need some model to render (mesh), here is a simple cube
// size,position of cube - change it that it is visible in your scene
const GLfloat a=1.0,x=0.0,y=0.0,z=0.0;
// cube points 3f x,y,z
GLfloat mesh_pos[]=
{
x-a,y-a,z-a,x-a,y+a,z-a,x+a,y+a,z-a,x+a,y-a,z-a,
x-a,y-a,z+a,x-a,y+a,z+a,x+a,y+a,z+a,x+a,y-a,z+a,
x-a,y-a,z-a,x-a,y-a,z+a,x+a,y-a,z+a,x+a,y-a,z-a,
x-a,y+a,z-a,x-a,y+a,z+a,x+a,y+a,z+a,x+a,y+a,z-a,
x-a,y-a,z-a,x-a,y+a,z-a,x-a,y+a,z+a,x-a,y-a,z+a,
x+a,y-a,z-a,x+a,y+a,z-a,x+a,y+a,z+a,x+a,y-a,z+a,
};
// cube colors 3f r,g,b
GLfloat mesh_col[]=
{
0.0,0.0,0.0,0.0,1.0,0.0,1.0,1.0,0.0,1.0,0.0,0.0,
0.0,0.0,1.0,0.0,1.0,1.0,1.0,1.0,1.0,1.0,0.0,1.0,
0.0,0.0,0.0,0.0,0.0,1.0,1.0,0.0,1.0,1.0,0.0,0.0,
0.0,1.0,0.0,0.0,1.0,1.0,1.0,1.0,1.0,1.0,1.0,0.0,
0.0,0.0,0.0,0.0,1.0,0.0,0.0,1.0,1.0,0.0,0.0,1.0,
1.0,0.0,0.0,1.0,1.0,0.0,1.0,1.0,1.0,1.0,0.0,1.0,
};
// cube normals 3f x,y,z
GLfloat mesh_tan[]=
{
-0.6,-0.6,-0.6,-0.6,+0.6,-0.6,+0.6,+0.6,-0.6,+0.6,-0.6,-0.6,
-0.6,-0.6,+0.6,-0.6,+0.6,+0.6,+0.6,+0.6,+0.6,+0.6,-0.6,+0.6,
-0.6,-0.6,-0.6,-0.6,-0.6,+0.6,+0.6,-0.6,+0.6,+0.6,-0.6,-0.6,
-0.6,+0.6,-0.6,-0.6,+0.6,+0.6,+0.6,+0.6,+0.6,+0.6,+0.6,-0.6,
-0.6,-0.6,-0.6,-0.6,+0.6,-0.6,-0.6,+0.6,+0.6,-0.6,-0.6,+0.6,
+0.6,-0.6,-0.6,+0.6,+0.6,-0.6,+0.6,+0.6,+0.6,+0.6,-0.6,+0.6,
};
// cube texture coords 2f s,t
GLfloat mesh_txr[]=
{
0.0,0.0,0.0,1.0,1.0,1.0,1.0,0.0,
0.0,0.0,0.0,1.0,1.0,1.0,1.0,0.0,
0.0,0.0,0.0,1.0,1.0,1.0,1.0,0.0,
0.0,0.0,0.0,1.0,1.0,1.0,1.0,0.0,
0.0,0.0,0.0,1.0,1.0,1.0,1.0,0.0,
0.0,0.0,0.0,1.0,1.0,1.0,1.0,0.0,
};
// init VAO/VBO
glGenVertexArrays(1,vao); // allocate 1 x VAO
glGenBuffers(_vbos,vbo); // allocate _vbos x VBO
// copy mesh to VAO/VBO ... after this you do not need the mesh anymore
GLint i,sz,n; // n = number of numbers per 1 entry
glBindVertexArray(vao[0]);
num_pnt=sizeof(mesh_pos)/(sizeof(GLfloat)*3); // num of all points in mesh
i=_OpenGLVAOgfx_pos; n=3; sz=sizeof(GLfloat)*n;
glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ARRAY_BUFFER,sz*num_pnt,mesh_pos,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,n,GL_FLOAT,GL_FALSE,0,0);
i=_OpenGLVAOgfx_col; n=3; sz=sizeof(GLfloat)*n;
glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ARRAY_BUFFER,sz*num_pnt,mesh_col,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,n,GL_FLOAT,GL_FALSE,0,0);
i=_OpenGLVAOgfx_tan; n=3; sz=sizeof(GLfloat)*n;
glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ARRAY_BUFFER,sz*num_pnt,mesh_tan,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,n,GL_FLOAT,GL_FALSE,0,0);
i=_OpenGLVAOgfx_txr; n=2; sz=sizeof(GLfloat)*n;
glBindBuffer(GL_ARRAY_BUFFER,vbo[i]);
glBufferData(GL_ARRAY_BUFFER,sz*num_pnt,mesh_txr,GL_STATIC_DRAW);
glEnableVertexAttribArray(i);
glVertexAttribPointer(i,n,GL_FLOAT,GL_FALSE,0,0);
glBindVertexArray(0);
}
//------------------------------------------------------------------------------
void VAO_draw() // call this to draw your mesh,... need to enable and bind textures,... before use
{
glDisable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
glDepthFunc(GL_LEQUAL);
glBindVertexArray(vao[0]);
glEnableVertexAttribArray(_vbo_pos);
glEnableVertexAttribArray(_vbo_col);
glEnableVertexAttribArray(_vbo_tan);
glDisableVertexAttribArray(_vbo_unused0);
glEnableVertexAttribArray(_vbo_txr);
glDrawArrays(GL_QUADS,0,num_pnt);
glDisableVertexAttribArray(_vbo_pos);
glDisableVertexAttribArray(_vbo_col);
glDisableVertexAttribArray(_vbo_tan);
glDisableVertexAttribArray(_vbo_unused0);
glDisableVertexAttribArray(_vbo_unused1);
glDisableVertexAttribArray(_vbo_txr);
glBindVertexArray(0);
}
//------------------------------------------------------------------------------
void VAO_exit() // clean up ... call this when you do not need VAO/VBO anymore
{
glDisableVertexAttribArray(_vbo_pos);
glDisableVertexAttribArray(_vbo_col);
glDisableVertexAttribArray(_vbo_tan);
glDisableVertexAttribArray(_vbo_unused0);
glDisableVertexAttribArray(_vbo_unused1);
glDisableVertexAttribArray(_vbo_txr);
glBindVertexArray(0);
glDeleteVertexArrays(1,vao);
glDeleteBuffers(_vbos,vbo);
}
//------------------------------------------------------------------------------
[edit3] if you are win32/64 user you can try my IDE for GLSL
It is very simple and easy to use, but cannot change texture/attrib locations. Press [F1] for help,... [F9] for run [F10] for return to normal OpenGL mode. Also txt-editor is little buggy sometimes but it is enough for my purpose.
GLSL IDE