Open GL ES2.0 - glDrawelements()
I am not able to use glDrawElements() command properly. I have checked with my buffers( both vertex and index) with my vertex and index data. Both come out to be same. And what i feel is that the main problem lies in drawing the object. I am giving my code below. Can anyone point the mistake.
- void GLWindow::paintGL() {
- glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); // Clear the background and depth-buffer for this frame
- GLuint vertexAttr = m_sampleProgram.attributeLocation("vertex");
- GLuint normalAttr = m_sampleProgram.attributeLocation("normal");
- GLuint texAttr = m_sampleProgram.attributeLocation("texCoord");
- GLuint matrixAttr = m_sampleProgram.uniformLocation("matrix");
- GLuint projAttr = m_sampleProgram.uniformLocation("proj");
- m_sampleProgram.bind();
- vertexBuffer.bind();
- indexBuffer.bind();
- m_sampleProgram.enableAttributeArray(vertexAttr);
- m_sampleProgram.setAttributeBuffer(vertexAttr, GL_FLOAT, 0 * sizeof(GLfloat), 3, 5 * sizeof(GLfloat));
- m_sampleProgram.enableAttributeArray(texAttr);
- m_sampleProgram.setAttributeBuffer(texAttr, GL_FLOAT, 3 * sizeof(GLfloat), 2, 6 * sizeof(GLfloat));
- m_sampleProgram.enableAttributeArray(normalAttr);
- m_sampleProgram.setAttributeBuffer(normalAttr, GL_FLOAT, 5 * sizeof(GLfloat), 3, 5 * sizeof(GLfloat));
- QMatrix4x4 projection;
- projection.perspective(45.0f, (float)width()/(float)height(), 0.01f, 1000.0f ); // Use perspective projection
- m_sampleProgram.setUniformValue( projAttr, projection ); // Set projection to the shader
- // Orientation for the <object> we are about to render
- QMatrix4x4 orientation;
- orientation.setToIdentity();
- orientation.translate(0.0f, 0.0f, -10.0f ); // 5 units away from camera
- static float ang = 0.0f;
- ang+=0.1f;
- orientation.rotate(ang, 1.0f, 0.0f, 0.0f );
- orientation.rotate(ang*0.7f, 0.0f, 1.0f, 0.0f );
- orientation.rotate(ang*1.4f, 0.0f, 0.0f, 1.0f );
- m_sampleProgram.setUniformValue( matrixAttr, orientation ); // Set orientation to the shader
- glEnable(GL_DEPTH_TEST);
- glBindTexture(GL_TEXTURE_2D, texture[0]);
- glDrawElements(GL_TRIANGLES, faceCount, GL_UNSIGNED_SHORT, 0); // draw the 3d <object>
- m_sampleProgram.disableAttributeArray(vertexAttr); // Disable the program
- m_sampleProgram.disableAttributeArray(texAttr);
- m_sampleProgram.disableAttributeArray(normalAttr);
- vertexBuffer.release();
- indexBuffer.release();
- m_sampleProgram.release();
- swapBuffers(); // Swap buffers manually since automatic swapping was disabled in a constructor.
- };
1 reply
- m_sampleProgram.enableAttributeArray(vertexAttr);
- m_sampleProgram.setAttributeBuffer(vertexAttr, GL_FLOAT, 0 * sizeof(GLfloat), 3, 5 * sizeof(GLfloat));
- m_sampleProgram.enableAttributeArray(texAttr);
- m_sampleProgram.setAttributeBuffer(texAttr, GL_FLOAT, 3 * sizeof(GLfloat), 2, 6 * sizeof(GLfloat));
- m_sampleProgram.enableAttributeArray(normalAttr);
- m_sampleProgram.setAttributeBuffer(normalAttr, GL_FLOAT, 5 * sizeof(GLfloat), 3, 5 * sizeof(GLfloat));
Looks like vertex strides are wrong.
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