sample1D 保留字，创建高度为1 的二维纹理

 

使用高度为1的OpenGL纹理2D对象的示例：

glTexStorage2D(GL_TEXTURE_2D, 8, GL_RGB8, 256, 1);
glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 256, 1, GL_RGB, GL_UNSIGNED_BYTE, palette);

并使用名为“ tex”的sampler2D对象在GLSL中进行相应的调用：

vec4 color = texture(tex, vec2(x, 1.0f));\n"
https://stackoverflow.com/questions/6210080/sampler1d-not-supported-in-nvidia-glsl

void set_color_palette()
{
//    if (m_colorTexture.isCreated()) {
//        m_colorTexture.destroy();
//    }
//    if (m_colorTexture.create()) {
//        m_colorTexture.setSize(m_palette.size());
//        m_colorTexture.setMinMagFilters(QOpenGLTexture::Linear,  QOpenGLTexture::Linear);
//        m_colorTexture.setWrapMode(QOpenGLTexture::ClampToEdge);
//        m_colorTexture.setFormat(QOpenGLTexture::RGB8_UNorm);
//        m_colorTexture.allocateStorage();
//        m_colorTexture.setData(QOpenGLTexture::RGB, QOpenGLTexture::Float32, m_palette.data());
//    }


    glGenTextures(1, &m_texturePalette);
    glBindTexture(GL_TEXTURE_2D, m_texturePalette);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);   // set texture wrapping to GL_REPEAT (default wrapping method)
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    // set texture filtering parameters
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, m_palette.size(), 1, 0, GL_RGB, GL_FLOAT, m_palette.data());

}

 

    if (m_paletteTexture.isCreated()) {
        m_paletteTexture.destroy();
    }
    if (m_paletteTexture.create()) {
        QImage img(m_palette.size(), 1, QImage::Format_RGB888);
        img.fill(QColor(0, 0, 0));
        for (int i = 0 ; i < m_palette.size(); i++) {
            img.setPixel(i,0, m_palette[i]);
        }

        m_paletteTexture.setData(img);
        m_paletteTexture.setMinificationFilter(QOpenGLTexture::Linear);
        m_paletteTexture.setMagnificationFilter(QOpenGLTexture::Linear);
        m_paletteTexture.setWrapMode(QOpenGLTexture::ClampToEdge);
    }

 

生成文字纹理

QOpenGLTexture *MeasureSpecimen::genTexture(uint textureWidth, uint textureHeight, const QString &text, int size)
{
    QOpenGLTexture *texture = new QOpenGLTexture(QOpenGLTexture::Target2D);

    QImage img(textureWidth, textureHeight, QImage::Format_RGBA8888);
    img.fill(QColor(0, 0, 0, 0));
    QPainter painter;

    QFont font;
    painter.begin(&img);
    font.setPointSize(size);
    painter.setFont(font);
    QPen pen;
    pen.setColor(Qt::black);
    pen.setStyle(Qt::SolidLine);
    painter.setPen(pen);
    QTextOption option;
    option.setAlignment(Qt::AlignHCenter | Qt::AlignTop);

    option.setWrapMode(QTextOption::WordWrap);
    QRectF rect(0, 0, textureWidth, textureHeight);
    painter.drawText(rect, text, option);

    texture->setData(img);
    texture->setMinificationFilter(QOpenGLTexture::Linear);
    texture->setMagnificationFilter(QOpenGLTexture::Linear);
    texture->setWrapMode(QOpenGLTexture::Repeat);

    return texture;
}