Crafter.Graphics/implementations/Crafter.Graphics-RenderingElement.cpp

/*
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;
#define STB_IMAGE_IMPLEMENTATION
#include "../lib/stb_image.h"
#include "../lib/stb_truetype.h"
module Crafter.Graphics:RenderingElement_impl;
import :RenderingElement;
import :Window;
import :Types;
import :Font;
import std;

using namespace Crafter;

RenderingElement::RenderingElement() : Transform() {

}


RenderingElement::RenderingElement(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) : Transform(anchorX, anchorY, relativeWidth, relativeHeight, anchorOffsetX, anchorOffsetY, z, ignoreScaling) {

}

RenderingElement::RenderingElement(std::uint_fast32_t bufferWidth, std::uint_fast32_t bufferHeight, 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) : bufferWidth(bufferWidth), bufferHeight(bufferHeight), buffer(bufferWidth*bufferHeight), Transform(anchorX, anchorY, relativeWidth, relativeHeight, anchorOffsetX, anchorOffsetY, z, ignoreScaling) {

}

RenderingElement::RenderingElement(const std::string_view imagePath, 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) : Transform(anchorX, anchorY, relativeWidth, relativeHeight, anchorOffsetX, anchorOffsetY, z, ignoreScaling) {
    RenderImage(imagePath);
}

RenderingElement::RenderingElement(const std::string_view text, float size, Pixel_BU8_GU8_RU8_AU8 pixel, Font& font, 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) : Transform(anchorX, anchorY, relativeWidth, relativeHeight, anchorOffsetX, anchorOffsetY, z, ignoreScaling) {
    RenderText(text, size, pixel, font);
}

void RenderingElement::ResizeBuffer(std::uint_fast32_t width, std::uint_fast32_t height) {
    this->bufferWidth = width;
    this->bufferHeight = height;
    buffer.resize(width * height);
}

void RenderingElement::RenderImage(const std::string_view path) {
    std::filesystem::path abs = std::filesystem::absolute(path);
    int xSize;
    int ySize;
    unsigned char* bgData = stbi_load(abs.string().c_str(), &xSize, &ySize, nullptr, 4);

    ResizeBuffer(xSize, ySize);

    for(std::uint_fast32_t x = 0; x < xSize; x++) {
		for(std::uint_fast32_t y = 0; y < ySize; y++) {
            std::uint_fast32_t idx = (x*ySize+y)*4;
			buffer[x*ySize+y].r = bgData[idx];
			buffer[x*ySize+y].g = bgData[idx+1];
			buffer[x*ySize+y].b = bgData[idx+2];
			buffer[x*ySize+y].a = bgData[idx+3];
		}
	}
}

void RenderingElement::RenderText(const std::string_view text, float size, Pixel_BU8_GU8_RU8_AU8 color, Font& font) {
    buffer.clear();

    float scale = stbtt_ScaleForPixelHeight(&font.font, size);

    int baseline = (int)(font.ascent * scale);

    std::uint_fast32_t bufferWidth = 0;
    for (const char c : text) {
        int advance, lsb;
        stbtt_GetCodepointHMetrics(&font.font, c, &advance, &lsb);
        bufferWidth += (int)(advance * scale);
    }

    ResizeBuffer(bufferWidth, (font.ascent - font.descent) * scale);

    int x = 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);

        for (int j = 0; j < h; j++) {
            for (int i = 0; i < w; i++) {
                buffer[(baseline + j + c_y1) * bufferWidth + (x + i + c_x1)] = {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);
        }
    }
}

void RenderingElement::CopyNearestNeighbour(Pixel_BU8_GU8_RU8_AU8* dst, std::uint_fast32_t dstWidth, std::uint_fast32_t dstHeight) const {
    for (std::uint_fast32_t y = 0; y < dstHeight; y++) {
		std::uint_fast32_t srcY = y * bufferHeight / dstHeight;
        for (std::uint_fast32_t x = 0; x < dstWidth; x++) {
            std::uint_fast32_t srcX = x * bufferWidth / dstWidth;
            dst[y * dstWidth + x] = buffer[srcY * bufferWidth + srcX];
        }
    }
}

void RenderingElement::UpdatePosition(Window& window) {
    window.ScaleElement(*this);
    bufferScaled.resize(scaled.width * scaled.height);
    CopyNearestNeighbour(bufferScaled.data(), scaled.width, scaled.height);
    for(Transform* child : children) {
		child->UpdatePosition(window, *this);
	}
}

void RenderingElement::UpdatePosition(Window& window, Transform& parent) {
    window.ScaleElement(*this, parent);
    bufferScaled.resize(scaled.width * scaled.height);
    CopyNearestNeighbour(bufferScaled.data(), scaled.width, scaled.height);
    for(Transform* child : children) {
		child->UpdatePosition(window, *this);
	}
}