bool CGUIFont::UpdateScrollInfo(const vecText &text, CScrollInfo &scrollInfo)
{
// draw at our scroll position
// we handle the scrolling as follows:
// We scroll on a per-pixel basis (eschewing the use of character indices
// which were also in use previously). The complete string, including suffix,
// is plotted to achieve the desired effect - normally just the one time, but
// if there is a wrap point within the viewport then it will be plotted twice.
// If the string is smaller than the viewport, then it may be plotted even
// more times than that.
//
if (g_application.ScreenSaverDisablesAutoScrolling())
return false;
if (scrollInfo.waitTime)
{
scrollInfo.waitTime--;
return false;
}
if (text.empty())
return false;
CScrollInfo old(scrollInfo);
// move along by the appropriate scroll amount
float scrollAmount = fabs(scrollInfo.GetPixelsPerFrame() * g_graphicsContext.GetGUIScaleX());
if (!scrollInfo.m_widthValid)
{
/* Calculate the pixel width of the complete string */
scrollInfo.m_textWidth = GetTextWidth(text);
scrollInfo.m_totalWidth = scrollInfo.m_textWidth + GetTextWidth(scrollInfo.suffix);
scrollInfo.m_widthValid = true;
}
scrollInfo.pixelPos += scrollAmount;
assert(scrollInfo.m_totalWidth != 0);
while (scrollInfo.pixelPos >= scrollInfo.m_totalWidth)
scrollInfo.pixelPos -= scrollInfo.m_totalWidth;
if (scrollInfo.pixelPos != old.pixelPos)
return true;
else
return false;
}
void CGUIFont::DrawScrollingText(float x, float y, const vecColors &colors, color_t shadowColor,
const vecText &text, uint32_t alignment, float maxWidth, CScrollInfo &scrollInfo)
{
if (!m_font) return;
if (!shadowColor) shadowColor = m_shadowColor;
float spaceWidth = GetCharWidth(L' ');
// max chars on screen + extra margin chars
vecText::size_type maxChars =
std::min<vecText::size_type>(
(text.size() + (vecText::size_type)scrollInfo.suffix.size()),
(vecText::size_type)((maxWidth * 1.05f) / spaceWidth));
if (!text.size() || ClippedRegionIsEmpty(x, y, maxWidth, alignment))
return; // nothing to render
maxWidth = ROUND(maxWidth / g_graphicsContext.GetGUIScaleX());
// draw at our scroll position
// we handle the scrolling as follows:
// We scroll on a per-pixel basis up until we have scrolled the first character outside
// of our viewport, whereby we cycle the string around, and reset the scroll position.
//
// pixelPos is the amount in pixels to move the string by.
// characterPos is the amount in characters to rotate the string by.
//
float offset = scrollInfo.pixelPos;
if (!scrollInfo.waitTime)
{
// move along by the appropriate scroll amount
float scrollAmount = fabs(scrollInfo.GetPixelsPerFrame() * g_graphicsContext.GetGUIScaleX());
if (scrollInfo.pixelSpeed > 0)
{
// we want to move scrollAmount, grab the next character
float charWidth = GetCharWidth(scrollInfo.GetCurrentChar(text));
if (scrollInfo.pixelPos + scrollAmount < charWidth)
scrollInfo.pixelPos += scrollAmount; // within the current character
else
{ // past the current character, decrement scrollAmount by the charWidth and move to the next character
while (scrollInfo.pixelPos + scrollAmount >= charWidth)
{
scrollAmount -= (charWidth - scrollInfo.pixelPos);
scrollInfo.pixelPos = 0;
scrollInfo.characterPos++;
if (scrollInfo.characterPos >= text.size() + scrollInfo.suffix.size())
{
scrollInfo.Reset();
break;
}
charWidth = GetCharWidth(scrollInfo.GetCurrentChar(text));
}
}
offset = scrollInfo.pixelPos;
}
else if (scrollInfo.pixelSpeed < 0)
{ // scrolling backwards
// we want to move scrollAmount, grab the next character
float charWidth = GetCharWidth(scrollInfo.GetCurrentChar(text));
if (scrollInfo.pixelPos + scrollAmount < charWidth)
scrollInfo.pixelPos += scrollAmount; // within the current character
else
{ // past the current character, decrement scrollAmount by the charWidth and move to the next character
while (scrollInfo.pixelPos + scrollAmount >= charWidth)
{
scrollAmount -= (charWidth - scrollInfo.pixelPos);
scrollInfo.pixelPos = 0;
if (scrollInfo.characterPos == 0)
{
scrollInfo.Reset();
scrollInfo.characterPos = text.size() + scrollInfo.suffix.size() - 1;
break;
}
scrollInfo.characterPos--;
charWidth = GetCharWidth(scrollInfo.GetCurrentChar(text));
}
}
offset = charWidth - scrollInfo.pixelPos;
}
}
else
scrollInfo.waitTime--;
// Now rotate our string as needed, only take a slightly larger then visible part of the text.
unsigned int pos = scrollInfo.characterPos;
vecText renderText;
renderText.reserve(maxChars);
for (vecText::size_type i = 0; i < maxChars; i++)
{
if (pos >= text.size() + scrollInfo.suffix.size())
pos = 0;
if (pos < text.size())
renderText.push_back(text[pos]);
else
renderText.push_back(scrollInfo.suffix[pos - text.size()]);
pos++;
}
vecColors renderColors;
for (unsigned int i = 0; i < colors.size(); i++)
renderColors.push_back(g_graphicsContext.MergeAlpha(colors[i] ? colors[i] : m_textColor));
bool scroll = !scrollInfo.waitTime && scrollInfo.pixelSpeed;
if (shadowColor)
{
shadowColor = g_graphicsContext.MergeAlpha(shadowColor);
vecColors shadowColors;
for (unsigned int i = 0; i < renderColors.size(); i++)
shadowColors.push_back((renderColors[i] & 0xff000000) != 0 ? shadowColor : 0);
m_font->DrawTextInternal(x - offset + 1, y + 1, shadowColors, renderText, alignment, maxWidth + scrollInfo.pixelPos + m_font->GetLineHeight(2.0f), scroll);
}
m_font->DrawTextInternal(x - offset, y, renderColors, renderText, alignment, maxWidth + scrollInfo.pixelPos + m_font->GetLineHeight(2.0f), scroll);
g_graphicsContext.RestoreClipRegion();
}