TCL3D problem with drawing multiple objects

[Hans Nikolaus Beck]

Hi
with TCL3D I want to draw 2 simple objects. The init code is like this:

proc Init {} {
global g_Demo g_Program
...
# Load the source of the vertex shader.
set vertexSource [tcl3dOglReadShaderFile [file join $g_Demo(scriptDir) "Vertex02.vs"]]
# Load the source of the fragment shader.
set fragmentSource [tcl3dOglReadShaderFile [file join $g_Demo(scriptDir) "Fragment01.fs"]]

set g_Program [tcl3dOglBuildProgram $vertexSource "" "" "" $fragmentSource]
set program [dict get $g_Program program]

# The location of the vertex in the shader program
set vertexLocation [glGetAttribLocation [dict get $g_Program program] "vertex"]
set g_Demo(projectionLocation) [glGetUniformLocation $program "projectionMatrix"]
set g_Demo(modelViewLocation) [glGetUniformLocation $program "modelViewMatrix"]
set g_Demo(colorLocation) [glGetUniformLocation $program "shapeColor"]

# generate a circle
set pointList [doCircles]
set pointVec [tcl3dVectorFromList GLfloat $pointList]
set pointVecSize [expr [llength $pointList] * [$pointVec elemsize]]

# The VAO for the vertices etc.
set g_Demo(vao) [tcl3dVector GLuint 1]
glGenVertexArrays 1 $g_Demo(vao)
glBindVertexArray [$g_Demo(vao) get 0]

# The VBO for the vertices.
set g_Demo(vertices) [tcl3dVector GLuint 1]
glGenBuffers 1 $g_Demo(vertices)
glBindBuffer GL_ARRAY_BUFFER [$g_Demo(vertices) get 0]
glBufferData GL_ARRAY_BUFFER $pointVecSize $pointVec GL_STATIC_DRAW

# the triangle
set pointVecTg [tcl3dVectorFromList GLfloat $pointListTriangle]
set pointVecSizeTg [expr [llength $pointListTriangle] * [$pointVecTg elemsize]]

# The VAO for the vertices etc.
set g_Demo(vaoTg) [tcl3dVector GLuint 1]
glGenVertexArrays 1 $g_Demo(vaoTg)
glBindVertexArray [$g_Demo(vaoTg) get 0]

# The VBO for the vertices.
set g_Demo(verticesTg) [tcl3dVector GLuint 1]
glGenBuffers 1 $g_Demo(verticesTg)
glBindBuffer GL_ARRAY_BUFFER [$g_Demo(verticesTg) get 0]
glBufferData GL_ARRAY_BUFFER $pointVecSizeTg $pointVecTg GL_STATIC_DRAW

glVertexAttribPointer $vertexLocation 4 GL_FLOAT GL_FALSE 0 "NULL"
glEnableVertexAttribArray $vertexLocation
glUseProgram [dict get $g_Program program]
}

and in the DisplayCallback :
...
glBindVertexArray [$g_Demo(vao) get 0]
glUniform4f $g_Demo(colorLocation) 1.0 1.0 1.0 1.0
glDrawArrays GL_LINE_LOOP 0 72

glBindVertexArray [$g_Demo(vaoTg) get 0]
glUniform4f $g_Demo(colorLocation) 1.0 0.3 0.9 1.0
glDrawArrays GL_TRIANGLES 0 3

glFlush

$toglwin swapbuffer
}

But only the second object (here Triangle) is drawn. I've read many tutorials and examples, I can not see what's my mistake.
Do you see any wrong thing?

Thanks and Cheers

Hans

[Hans Nikolaus Beck]

I've found the solution by myself. I've forgot to do the block

glVertexAttribPointer $vertexLocation 4 GL_FLOAT GL_FALSE 0 "NULL"
glEnableVertexAttribArray $vertexLocation
glUseProgram [dict get $g_Program program]

for *every* VAO/VBO object.

Cheers

Hans