Hi.
The rendering with shaders doesnt work (nothing on screen). But without it everthing is OK. I use simple custom vertex structure, buffers.
Vertex structure:
struct MyVertex
{
GLfloat x,y,z;
GLfloat r,g,b;
MyVertex() : x(0), y(0), z(0), r(0), g(0), b(0){};
MyVertex(GLfloat x, GLfloat y, GLfloat z, GLfloat r, GLfloat g, GLfloat b) : x(x), y(y), z(z), r(r), g(g), b(b){};
};
struct MyVertex
{
GLfloat x,y,z;
GLfloat r,g,b;
MyVertex() : x(0), y(0), z(0), r(0), g(0), b(0){};
MyVertex(GLfloat x, GLfloat y, GLfloat z, GLfloat r, GLfloat g, GLfloat b) : x(x), y(y), z(z), r(r), g(g), b(b){};
};
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Triangle constructor and its data:
MyTriangle::MyTriangle() : mVertexVBO(QGLBuffer::VertexBuffer), mIndexVBO(QGLBuffer::IndexBuffer), mVertices(3), mIndices(3)
{
mVertices[0]=MyVertex( 0.0f, 1.0f,-2.0f, 1.0f,0.0f,0.0f);
mVertices[1]=MyVertex(-1.0f,-1.0f,-2.0f, 0.0f,1.0f,0.0f);
mVertices[2]=MyVertex( 1.0f,-1.0f,-2.0f, 0.0f,0.0f,1.0f);
mIndices[0]=0;
mIndices[1]=1;
mIndices[2]=2;
}
MyTriangle::MyTriangle() : mVertexVBO(QGLBuffer::VertexBuffer), mIndexVBO(QGLBuffer::IndexBuffer), mVertices(3), mIndices(3)
{
mVertices[0]=MyVertex( 0.0f, 1.0f,-2.0f, 1.0f,0.0f,0.0f);
mVertices[1]=MyVertex(-1.0f,-1.0f,-2.0f, 0.0f,1.0f,0.0f);
mVertices[2]=MyVertex( 1.0f,-1.0f,-2.0f, 0.0f,0.0f,1.0f);
mIndices[0]=0;
mIndices[1]=1;
mIndices[2]=2;
}
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Shaders preparation:
bool MyQGLWidget::prepareShaders()
{
QGLShader shaderVert(QGLShader::Vertex);
QGLShader shaderFrag(QGLShader::Fragment);
bool isCompiledVert
= shaderVert.
compileSourceFile(QString("../QGLTriangle02VOBSL/shader_vert.glsl"));
bool isCompiledFrag
= shaderFrag.
compileSourceFile(QString("../QGLTriangle02VOBSL/shader_frag.glsl"));
if(isCompiledVert && isCompiledFrag)
{
bool isAddVert = mShaderProgram.addShader(&shaderVert);
bool isAddFrag = mShaderProgram.addShader(&shaderFrag);
if(isAddVert && isAddFrag)
{
bool isLink = mShaderProgram.link();
if(isLink)
{
return mShaderProgram.bind();
}
}
}
return false;
}
bool MyQGLWidget::prepareShaders()
{
QGLShader shaderVert(QGLShader::Vertex);
QGLShader shaderFrag(QGLShader::Fragment);
bool isCompiledVert = shaderVert.compileSourceFile(QString("../QGLTriangle02VOBSL/shader_vert.glsl"));
bool isCompiledFrag = shaderFrag.compileSourceFile(QString("../QGLTriangle02VOBSL/shader_frag.glsl"));
if(isCompiledVert && isCompiledFrag)
{
bool isAddVert = mShaderProgram.addShader(&shaderVert);
bool isAddFrag = mShaderProgram.addShader(&shaderFrag);
if(isAddVert && isAddFrag)
{
bool isLink = mShaderProgram.link();
if(isLink)
{
return mShaderProgram.bind();
}
}
}
return false;
}
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Not working drawing function: (with shaders)
void MyTriangle::drawBuffers(QGLShaderProgram& program)
{
int vertexLocation = program.attributeLocation("in_Position");
int colorLocation = program.attributeLocation("in_Color");
program.enableAttributeArray(vertexLocation);
program.enableAttributeArray(colorLocation);
program.setAttributeBuffer(vertexLocation, GL_FLOAT, 0, 3, sizeof(MyVertex));
program.setAttributeBuffer(colorLocation, GL_FLOAT, 12, 3, sizeof(MyVertex));
glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
program.disableAttributeArray(vertexLocation);
program.disableAttributeArray(colorLocation);
}
void MyTriangle::drawBuffers(QGLShaderProgram& program)
{
int vertexLocation = program.attributeLocation("in_Position");
int colorLocation = program.attributeLocation("in_Color");
program.enableAttributeArray(vertexLocation);
program.enableAttributeArray(colorLocation);
program.setAttributeBuffer(vertexLocation, GL_FLOAT, 0, 3, sizeof(MyVertex));
program.setAttributeBuffer(colorLocation, GL_FLOAT, 12, 3, sizeof(MyVertex));
glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
program.disableAttributeArray(vertexLocation);
program.disableAttributeArray(colorLocation);
}
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Working drawing function (without shaders):
void MyTriangle::drawBuffers()
{
glEnableClientState(GL_COLOR_ARRAY);
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, sizeof(MyVertex), BUFFER_OFFSET(0));
glColorPointer(3, GL_FLOAT, sizeof(MyVertex), BUFFER_OFFSET(12));
glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_COLOR_ARRAY);
}
void MyTriangle::drawBuffers()
{
glEnableClientState(GL_COLOR_ARRAY);
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(3, GL_FLOAT, sizeof(MyVertex), BUFFER_OFFSET(0));
glColorPointer(3, GL_FLOAT, sizeof(MyVertex), BUFFER_OFFSET(12));
glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT, 0);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_COLOR_ARRAY);
}
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Shaders:
Vertex shader:
#version 410 compatibility
in vec3 in_Position;
in vec3 in_Color;
out vec3 pass_Color;
void main(void)
{
gl_Position = vec4(in_Position, 1.0);
pass_Color = in_Color;
}
#version 410 compatibility
in vec3 in_Position;
in vec3 in_Color;
out vec3 pass_Color;
void main(void)
{
gl_Position = vec4(in_Position, 1.0);
pass_Color = in_Color;
}
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Fragment shader:
#version 410 compatibility
in vec3 pass_Color;
out vec4 out_Color;
void main(void)
{
out_Color = vec4(pass_Color, 1.0);
}
#version 410 compatibility
in vec3 pass_Color;
out vec4 out_Color;
void main(void)
{
out_Color = vec4(pass_Color, 1.0);
}
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I have:
GL_VERSION: 4.1.0
GL_SHADING_LANGUAGE_VERSION: 4.10 NVIDIA via Cg compiler
What is wrong?
I attached fully function project made in QtCreator: QGLTriangle02VOBSL.zip
I think that I will do the same in pure OpenGL without Qt. To look for mistakes. But if you can provide some answers or clues. That will be awesome.
OpengGL with Shaders. I'm stuck. Triangle with Buffer + not working shader.
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, Because that stuf was deprecated (glOrtho, glProjection, glTranslate, etc...).
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