text wrap

This commit is contained in:
Jorijn van der Graaf 2025-11-26 03:41:00 +01:00
commit 10308bd805
2 changed files with 235 additions and 39 deletions

View file

@ -34,64 +34,249 @@ TextElement::TextElement(std::int_fast32_t anchorX, std::int_fast32_t anchorY, s
}
void TextElement::RenderText(const std::string_view text, float size, Pixel_BU8_GU8_RU8_AU8 color, Font& font) {
void TextElement::RenderText(const std::string_view text, float size, Pixel_BU8_GU8_RU8_AU8 color, Font& font, TextAlignment alignment, TextOverflowMode overflowMode) {
// Calculate the actual size needed for the text
float scale = stbtt_ScaleForPixelHeight(&font.font, size);
int baseline = (int)(font.ascent * scale);
std::uint_fast32_t textWidth = 0;
for (const char c : text) {
int advance, lsb;
stbtt_GetCodepointHMetrics(&font.font, c, &advance, &lsb);
textWidth += (int)(advance * scale);
}
// Clear the scaled buffer
for (auto& pixel : bufferScaled) {
pixel = {0, 0, 0, 0};
}
// Only render text if we have space
if (textWidth <= scaled.width && (font.ascent - font.descent) * scale <= scaled.height) {
// Calculate starting position to center text horizontally and vertically
int startX = (scaled.width - textWidth) / 2;
int startY = ( scaled.height - (font.ascent - font.descent) * scale) / 2;
startY += baseline; // Adjust for baseline
// If we have no text or no space, return early
if (text.empty() || scaled.width == 0 || scaled.height == 0) {
return;
}
// Calculate total text width
std::uint_fast32_t totalTextWidth = 0;
std::vector<int> charAdvances;
std::vector<int> charLSBs;
for (const char c : text) {
int advance, lsb;
stbtt_GetCodepointHMetrics(&font.font, c, &advance, &lsb);
charAdvances.push_back(advance);
charLSBs.push_back(lsb);
totalTextWidth += (int)(advance * scale);
}
// Handle text overflow based on mode
if (overflowMode == TextOverflowMode::Wrap) {
// For wrapped text, we need to handle line breaks and calculate lines
std::vector<std::string_view> lines;
std::string_view remaining = text;
int x = startX;
for (std::uint_fast32_t i = 0; i < text.size(); i++) {
int codepoint = text[i];
// Simple word wrapping approach
while (!remaining.empty()) {
// Find next newline or end of string
auto newlinePos = remaining.find('\n');
if (newlinePos != std::string_view::npos) {
lines.emplace_back(remaining.substr(0, newlinePos));
remaining = remaining.substr(newlinePos + 1);
} else {
lines.emplace_back(remaining);
break;
}
}
int ax;
int lsb;
stbtt_GetCodepointHMetrics(&font.font, codepoint, &ax, &lsb);
// Now process each line with proper wrapping
std::uint_fast32_t lineHeight = (font.ascent - font.descent) * scale;
std::uint_fast32_t maxLineWidth = scaled.width;
std::uint_fast32_t currentLineStartY = 0;
std::uint_fast32_t maxLines = scaled.height / lineHeight;
// Process lines up to maximum allowed
for (std::size_t lineIndex = 0; lineIndex < std::min(lines.size(), maxLines); ++lineIndex) {
std::string_view line = lines[lineIndex];
// Calculate line width
std::uint_fast32_t lineWidth = 0;
std::vector<int> lineAdvances;
for (const char c : line) {
int advance, lsb;
stbtt_GetCodepointHMetrics(&font.font, c, &advance, &lsb);
lineAdvances.push_back(advance);
lineWidth += (int)(advance * scale);
}
// Determine horizontal position based on alignment
int startX = 0;
switch (alignment) {
case TextAlignment::Left:
startX = 0;
break;
case TextAlignment::Center:
startX = (scaled.width - lineWidth) / 2;
break;
case TextAlignment::Right:
startX = scaled.width - lineWidth;
break;
}
// Render the line
int x = startX;
int startY = currentLineStartY + baseline + (lineIndex * lineHeight);
for (std::size_t i = 0; i < line.size(); ++i) {
int codepoint = line[i];
int ax;
int lsb;
stbtt_GetCodepointHMetrics(&font.font, codepoint, &ax, &lsb);
int c_x1, c_y1, c_x2, c_y2;
stbtt_GetCodepointBitmapBox(&font.font, codepoint, scale, scale, &c_x1, &c_y1, &c_x2, &c_y2);
int c_x1, c_y1, c_x2, c_y2;
stbtt_GetCodepointBitmapBox(&font.font, codepoint, scale, scale, &c_x1, &c_y1, &c_x2, &c_y2);
int w = c_x2 - c_x1;
int h = c_y2 - c_y1;
int w = c_x2 - c_x1;
int h = c_y2 - c_y1;
std::vector<unsigned char> bitmap(w * h);
stbtt_MakeCodepointBitmap(&font.font, bitmap.data(), w, h, w, scale, scale, codepoint);
std::vector<unsigned char> bitmap(w * h);
stbtt_MakeCodepointBitmap(&font.font, bitmap.data(), w, h, w, scale, scale, codepoint);
// Only render characters that fit within the scaled bounds
for (int j = 0; j < h; j++) {
for (int i = 0; i < w; i++) {
int bufferX = x + i + c_x1;
int bufferY = startY + j + c_y1;
// Only draw pixels that are within our scaled buffer bounds
if (bufferX >= 0 && bufferX < (int)scaled.width && bufferY >= 0 && bufferY < (int) scaled.height) {
bufferScaled[bufferY * scaled.width + bufferX] = {color.r, color.g, color.b, bitmap[j * w + i]};
// Only render characters that fit within the scaled bounds
for (int j = 0; j < h; j++) {
for (int i = 0; i < w; i++) {
int bufferX = x + i + c_x1;
int bufferY = startY + j + c_y1;
// Only draw pixels that are within our scaled buffer bounds
if (bufferX >= 0 && bufferX < (int)scaled.width && bufferY >= 0 && bufferY < (int)scaled.height) {
bufferScaled[bufferY * scaled.width + bufferX] = {color.r, color.g, color.b, bitmap[j * w + i]};
}
}
}
x += (int)(ax * scale);
if (i + 1 < line.size()) {
x += (int)stbtt_GetCodepointKernAdvance(&font.font, codepoint, line[i+1]);
}
}
currentLineStartY += lineHeight;
}
} else {
// Clip mode - render text that fits within bounds
// If the text fits entirely, render it normally
if (totalTextWidth <= scaled.width && (font.ascent - font.descent) * scale <= scaled.height) {
// Calculate starting position based on alignment
int startX = 0;
switch (alignment) {
case TextAlignment::Left:
startX = 0;
break;
case TextAlignment::Center:
startX = (scaled.width - totalTextWidth) / 2;
break;
case TextAlignment::Right:
startX = scaled.width - totalTextWidth;
break;
}
int startY = (scaled.height - (font.ascent - font.descent) * scale) / 2;
startY += baseline; // Adjust for baseline
int x = startX;
for (std::uint_fast32_t i = 0; i < text.size(); i++) {
int codepoint = text[i];
x += (int)(ax * scale);
int ax;
int lsb;
stbtt_GetCodepointHMetrics(&font.font, codepoint, &ax, &lsb);
if (i + 1 < text.size()) {
x += (int)stbtt_GetCodepointKernAdvance(&font.font, codepoint, text[i+1] * scale);
int c_x1, c_y1, c_x2, c_y2;
stbtt_GetCodepointBitmapBox(&font.font, codepoint, scale, scale, &c_x1, &c_y1, &c_x2, &c_y2);
int w = c_x2 - c_x1;
int h = c_y2 - c_y1;
std::vector<unsigned char> bitmap(w * h);
stbtt_MakeCodepointBitmap(&font.font, bitmap.data(), w, h, w, scale, scale, codepoint);
// Only render characters that fit within the scaled bounds
for (int j = 0; j < h; j++) {
for (int i = 0; i < w; i++) {
int bufferX = x + i + c_x1;
int bufferY = startY + j + c_y1;
// Only draw pixels that are within our scaled buffer bounds
if (bufferX >= 0 && bufferX < (int)scaled.width && bufferY >= 0 && bufferY < (int)scaled.height) {
bufferScaled[bufferY * scaled.width + bufferX] = {color.r, color.g, color.b, bitmap[j * w + i]};
}
}
}
x += (int)(ax * scale);
if (i + 1 < text.size()) {
x += (int)stbtt_GetCodepointKernAdvance(&font.font, codepoint, text[i+1] * scale);
}
}
} else {
// Text doesn't fit, but we still render what we can
// For now, we'll just render the first part that fits
int startX = 0;
switch (alignment) {
case TextAlignment::Left:
startX = 0;
break;
case TextAlignment::Center:
startX = (scaled.width - totalTextWidth) / 2;
break;
case TextAlignment::Right:
startX = scaled.width - totalTextWidth;
break;
}
// Clamp to visible area
int startY = (scaled.height - (font.ascent - font.descent) * scale) / 2;
startY += baseline; // Adjust for baseline
int x = startX;
int renderedChars = 0;
for (std::uint_fast32_t i = 0; i < text.size(); i++) {
int codepoint = text[i];
int ax;
int lsb;
stbtt_GetCodepointHMetrics(&font.font, codepoint, &ax, &lsb);
int c_x1, c_y1, c_x2, c_y2;
stbtt_GetCodepointBitmapBox(&font.font, codepoint, scale, scale, &c_x1, &c_y1, &c_x2, &c_y2);
int w = c_x2 - c_x1;
int h = c_y2 - c_y1;
std::vector<unsigned char> bitmap(w * h);
stbtt_MakeCodepointBitmap(&font.font, bitmap.data(), w, h, w, scale, scale, codepoint);
// Only render characters that fit within the scaled bounds
for (int j = 0; j < h; j++) {
for (int i = 0; i < w; i++) {
int bufferX = x + i + c_x1;
int bufferY = startY + j + c_y1;
// Only draw pixels that are within our scaled buffer bounds
if (bufferX >= 0 && bufferX < (int)scaled.width && bufferY >= 0 && bufferY < (int)scaled.height) {
bufferScaled[bufferY * scaled.width + bufferX] = {color.r, color.g, color.b, bitmap[j * w + i]};
}
}
}
x += (int)(ax * scale);
if (x > (int)scaled.width) {
// Text would overflow, stop rendering
break;
}
if (i + 1 < text.size()) {
x += (int)stbtt_GetCodepointKernAdvance(&font.font, codepoint, text[i+1] * scale);
}
renderedChars++;
}
}
}