Crafter.Graphics/implementations/Crafter.Graphics-TextElement.cpp
2025-11-26 03:35:58 +01:00

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3.8 KiB
C++

/*
Crafter®.Graphics
Copyright (C) 2025 Catcrafts®
Catcrafts.net
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3.0 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
module;
#include "../lib/stb_truetype.h"
module Crafter.Graphics:TextElement_impl;
import :TextElement;
import :RenderingElement;
import :Window;
import :Types;
import :Font;
import std;
using namespace Crafter;
TextElement::TextElement(std::int_fast32_t anchorX, std::int_fast32_t anchorY, std::uint_fast32_t relativeWidth, std::uint_fast32_t relativeHeight, std::int_fast32_t anchorOffsetX, std::int_fast32_t anchorOffsetY, std::int_fast32_t z, bool ignoreScaling) : RenderingElementPreScaled(false, anchorX, anchorY, relativeWidth, relativeHeight, anchorOffsetX, anchorOffsetY, z, ignoreScaling) {
}
void TextElement::RenderText(const std::string_view text, float size, Pixel_BU8_GU8_RU8_AU8 color, Font& font) {
// 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
int x = startX;
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 (i + 1 < text.size()) {
x += (int)stbtt_GetCodepointKernAdvance(&font.font, codepoint, text[i+1] * scale);
}
}
}
}