CRenderizableShaderWireFrame.cpp

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/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2020, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#include "opengl-precomp.h"  // Precompiled header

#include <mrpt/opengl/CRenderizableShaderWireFrame.h>
#include <mrpt/opengl/Shader.h>
#include <mrpt/opengl/opengl_api.h>

using namespace mrpt;
using namespace mrpt::opengl;

IMPLEMENTS_VIRTUAL_SERIALIZABLE(
    CRenderizableShaderWireFrame, CRenderizable, mrpt::opengl)

// Dtor:
CRenderizableShaderWireFrame::~CRenderizableShaderWireFrame() = default;

void CRenderizableShaderWireFrame::renderUpdateBuffers() const
{
#if MRPT_HAS_OPENGL_GLUT

    // Generate vertices & colors:
    const_cast<CRenderizableShaderWireFrame&>(*this)
        .onUpdateBuffers_Wireframe();

    // Define OpenGL buffers:
    m_vertexBuffer.createOnce();
    m_vertexBuffer.bind();
    m_vertexBuffer.allocate(
        m_vertex_buffer_data.data(),
        sizeof(m_vertex_buffer_data[0]) * m_vertex_buffer_data.size());

    // color buffer:
    m_colorBuffer.createOnce();
    m_colorBuffer.bind();
    m_colorBuffer.allocate(
        m_color_buffer_data.data(),
        sizeof(m_color_buffer_data[0]) * m_color_buffer_data.size());

    // VAO: required to use glEnableVertexAttribArray()
    m_vao.createOnce();
#endif
}

void CRenderizableShaderWireFrame::render(const RenderContext& rc) const
{
#if MRPT_HAS_OPENGL_GLUT
    // TODO: Port thick lines to opengl3?
    // glLineWidth(m_lineWidth);

    glEnable(GL_LINE_SMOOTH);
    CHECK_OPENGL_ERROR();

    // Set up the vertex array:
    const GLuint attr_position = rc.shader->attributeId("position");
    m_vao.bind();
    glEnableVertexAttribArray(attr_position);
    m_vertexBuffer.bind();
    glVertexAttribPointer(
        attr_position, /* attribute */
        3, /* size */
        GL_FLOAT, /* type */
        GL_FALSE, /* normalized? */
        0, /* stride */
        BUFFER_OFFSET(0) /* array buffer offset */
    );
    CHECK_OPENGL_ERROR();

    // Set up the color array:
    const GLuint attr_color = rc.shader->attributeId("vertexColor");
    glEnableVertexAttribArray(attr_color);
    m_colorBuffer.bind();
    glVertexAttribPointer(
        attr_color, /* attribute */
        4, /* size */
        GL_UNSIGNED_BYTE, /* type */
        GL_TRUE, /* normalized? */
        0, /* stride */
        BUFFER_OFFSET(0) /* array buffer offset */
    );
    CHECK_OPENGL_ERROR();

    glDrawArrays(GL_LINES, 0, m_vertex_buffer_data.size());
    CHECK_OPENGL_ERROR();

    glDisableVertexAttribArray(attr_position);
    glDisableVertexAttribArray(attr_color);
    CHECK_OPENGL_ERROR();
#endif
}