Method Typeset

GTE/Graphics/Font.cpp:123–192

}

void Font::Typeset(int32_t viewportWidth, int32_t viewportHeight, int32_t x, int32_t y,
    Vector4<float> const& color, std::string const& message) const
{
    // Get texel translation units, depends on viewport width and height.
    float const vdx = 1.0f / static_cast<float>(viewportWidth);
    float const vdy = 1.0f / static_cast<float>(viewportHeight);

    // Get texture information.
    float tw = static_cast<float>(mTexture->GetWidth());
    float th = static_cast<float>(mTexture->GetHeight());

    // Get vertex buffer information.
    uint32_t vertexSize = mVertexBuffer->GetFormat().GetVertexSize();
    char* data = mVertexBuffer->GetData();

    float x0 = 0.0f;
    uint32_t const length = std::min(
        static_cast<uint32_t>(message.length()), mMaxMessageLength);
    for (uint32_t i = 0; i < length; ++i)
    {
        // Get character data.
        int32_t c = static_cast<int32_t>(message[i]);
        float const tx0 = mCharacterData[c];
        float const tx1 = mCharacterData[c + 1];
        float charWidthM1 = (tx1 - tx0)*tw - 1.0f;  // in pixels

        // 0 -- 2   4 -- 6  ...
        // | \  |   | \  | 
        // |  \ |   |  \ | 
        // 1 -- 3   5 -- 7  ...
        size_t const fourI = 4 * static_cast<size_t>(i);
        float* v0 = reinterpret_cast<float*>(data + (fourI + 0)*vertexSize);
        float* v1 = reinterpret_cast<float*>(data + (fourI + 1)*vertexSize);
        float* v2 = reinterpret_cast<float*>(data + (fourI + 2)*vertexSize);
        float* v3 = reinterpret_cast<float*>(data + (fourI + 3)*vertexSize);

        // Set bottom left vertex y coordinate.
        v1[1] = vdy * th;

        // Set x-coordinates.
        float x1 = x0 + charWidthM1 *vdx;
        v0[0] = x0;
        v1[0] = x0;
        v2[0] = x1;
        v3[0] = x1;

        // Set bottom right-side y-coordinate.
        v3[1] = vdy * th;

        // Set the four texture x-coordinates.  The y-coordinates were set in
        // the constructor.
        v0[2] = tx0;
        v1[2] = tx0;
        v2[2] = tx1;
        v3[2] = tx1;

        // Update left x coordinate for next quad
        x0 = x1;