Method renderText

Source/Falcor/Utils/UI/TextRenderer.cpp:146–193

}

void TextRenderer::renderText(RenderContext* pRenderContext, const std::string& text, const ref<Fbo>& pDstFbo, float2 pos)
{
    // Make sure we enough space for the next char
    FALCOR_ASSERT(text.size() < kMaxCharCount);
    setCbData(pDstFbo);
    const auto& pVao = mpVaos[mVaoIndex];
    const auto& pVb = pVao->getVertexBuffer(0);
    Vertex* verts = reinterpret_cast<Vertex*>(pVb->map());

    float startX = pos.x;
    uint32_t vertexCount = 0; // Not the same as text.size(), since some special characters are ignored

    // Create the vertex-buffer
    for (const auto& c : text)
    {
        if (c == '\n')
        {
            pos.y += mpFont->getFontHeight();
            pos.x = startX;
        }
        else if (c == '\t')
            pos.x += mpFont->getTabWidth();
        else if (c == ' ')
            pos.x += mpFont->getLettersSpacing();
        else
        {
            // Regular character
            const Font::CharTexCrdDesc& desc = mpFont->getCharDesc(c);
            for (uint32_t i = 0; i < std::size(kVertexPos); i++, vertexCount++)
            {
                float2 posScale = kVertexPos[i];
                float2 charPos = desc.size * posScale;
                charPos += pos;
                verts[vertexCount].screenPos = charPos;
                verts[vertexCount].texCoord = desc.topLeft + desc.size * kVertexPos[i];
            }
            pos.x += mpFont->getLettersSpacing();
        }
    }

    // Submit
    pVb->unmap();
    mpPass->getState()->setVao(pVao);
    mpPass->getState()->setFbo(pDstFbo);
    mpPass->draw(pRenderContext, vertexCount, 0);

    mVaoIndex = (mVaoIndex + 1) % kVaoCount;
}

} // namespace Falcor