DoomRTX/neo/renderer/tr_font.cpp

/*
===========================================================================

IceTech GPL Source Code
Copyright (C) 2026 Justin Marshall

This file is part of the IceTech GPL Source Code ("IceTech Source Code").

IceTech Source Code is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

IceTech Source Code 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with IceTech Source Code.  If not, see <http://www.gnu.org/licenses/>.

In addition, the IceTech Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the IceTech Source Code.  If not, please request a copy in writing from id Software at the address below.

If you have questions concerning this license or the applicable additional terms, you may contact in writing Justin Marshall, justinmarshall20@gmail.com

===========================================================================
*/

#include "precompiled.h"
#include "tr_local.h"

#define FILESIZE_fontInfo_t (20548)

#ifdef BUILD_FREETYPE
#include "../ft2/fterrors.h"
#include "../ft2/ftsystem.h"
#include "../ft2/ftimage.h"
#include "../ft2/freetype.h"
#include "../ft2/ftoutln.h"

#define _FLOOR(x)  ((x) & -64)
#define _CEIL(x)   (((x)+63) & -64)
#define _TRUNC(x)  ((x) >> 6)

FT_Library ftLibrary = NULL;
#endif


#ifdef BUILD_FREETYPE

/*
============
R_GetGlyphInfo
============
*/
void R_GetGlyphInfo(FT_GlyphSlot glyph, int* left, int* right, int* width, int* top, int* bottom, int* height, int* pitch) {

	*left = _FLOOR(glyph->metrics.horiBearingX);
	*right = _CEIL(glyph->metrics.horiBearingX + glyph->metrics.width);
	*width = _TRUNC(*right - *left);

	*top = _CEIL(glyph->metrics.horiBearingY);
	*bottom = _FLOOR(glyph->metrics.horiBearingY - glyph->metrics.height);
	*height = _TRUNC(*top - *bottom);
	*pitch = (qtrue ? (*width + 3) & -4 : (*width + 7) >> 3);
}

/*
============
R_RenderGlyph
============
*/
FT_Bitmap* R_RenderGlyph(FT_GlyphSlot glyph, glyphInfo_t* glyphOut) {
	FT_Bitmap* bit2;
	int left, right, width, top, bottom, height, pitch, size;

	R_GetGlyphInfo(glyph, &left, &right, &width, &top, &bottom, &height, &pitch);

	if (glyph->format == ft_glyph_format_outline) {
		size = pitch * height;

		bit2 = Mem_Alloc(sizeof(FT_Bitmap));

		bit2->width = width;
		bit2->rows = height;
		bit2->pitch = pitch;
		bit2->pixel_mode = ft_pixel_mode_grays;
		//bit2->pixel_mode = ft_pixel_mode_mono;
		bit2->buffer = Mem_Alloc(pitch * height);
		bit2->num_grays = 256;

		memset(bit2->buffer, 0, size);

		FT_Outline_Translate(&glyph->outline, -left, -bottom);

		FT_Outline_Get_Bitmap(ftLibrary, &glyph->outline, bit2);

		glyphOut->height = height;
		glyphOut->pitch = pitch;
		glyphOut->top = (glyph->metrics.horiBearingY >> 6) + 1;
		glyphOut->bottom = bottom;

		return bit2;
	}
	else {
		common->Printf("Non-outline fonts are not supported\n");
	}
	return NULL;
}

/*
============
RE_ConstructGlyphInfo
============
*/
glyphInfo_t* RE_ConstructGlyphInfo(unsigned char* imageOut, int* xOut, int* yOut, int* maxHeight, FT_Face face, const unsigned char c, qboolean calcHeight) {
	int i;
	static glyphInfo_t glyph;
	unsigned char* src, * dst;
	float scaled_width, scaled_height;
	FT_Bitmap* bitmap = NULL;

	memset(&glyph, 0, sizeof(glyphInfo_t));
	// make sure everything is here
	if (face != NULL) {
		FT_Load_Glyph(face, FT_Get_Char_Index(face, c), FT_LOAD_DEFAULT);
		bitmap = R_RenderGlyph(face->glyph, &glyph);
		if (bitmap) {
			glyph.xSkip = (face->glyph->metrics.horiAdvance >> 6) + 1;
		}
		else {
			return &glyph;
		}

		if (glyph.height > *maxHeight) {
			*maxHeight = glyph.height;
		}

		if (calcHeight) {
			Mem_Free(bitmap->buffer);
			Mem_Free(bitmap);
			return &glyph;
		}

		/*
				// need to convert to power of 2 sizes so we do not get
				// any scaling from the gl upload
				for (scaled_width = 1 ; scaled_width < glyph.pitch ; scaled_width<<=1)
					;
				for (scaled_height = 1 ; scaled_height < glyph.height ; scaled_height<<=1)
					;
		*/

		scaled_width = glyph.pitch;
		scaled_height = glyph.height;

		// we need to make sure we fit
		if (*xOut + scaled_width + 1 >= 255) {
			if (*yOut + *maxHeight + 1 >= 255) {
				*yOut = -1;
				*xOut = -1;
				Mem_Free(bitmap->buffer);
				Mem_Free(bitmap);
				return &glyph;
			}
			else {
				*xOut = 0;
				*yOut += *maxHeight + 1;
			}
		}
		else if (*yOut + *maxHeight + 1 >= 255) {
			*yOut = -1;
			*xOut = -1;
			Mem_Free(bitmap->buffer);
			Mem_Free(bitmap);
			return &glyph;
		}

		src = bitmap->buffer;
		dst = imageOut + (*yOut * 256) + *xOut;

		if (bitmap->pixel_mode == ft_pixel_mode_mono) {
			for (i = 0; i < glyph.height; i++) {
				int j;
				unsigned char* _src = src;
				unsigned char* _dst = dst;
				unsigned char mask = 0x80;
				unsigned char val = *_src;
				for (j = 0; j < glyph.pitch; j++) {
					if (mask == 0x80) {
						val = *_src++;
					}
					if (val & mask) {
						*_dst = 0xff;
					}
					mask >>= 1;

					if (mask == 0) {
						mask = 0x80;
					}
					_dst++;
				}

				src += glyph.pitch;
				dst += 256;

			}
		}
		else {
			for (i = 0; i < glyph.height; i++) {
				memcpy(dst, src, glyph.pitch);
				src += glyph.pitch;
				dst += 256;
			}
		}

		// we now have an 8 bit per pixel grey scale bitmap
		// that is width wide and pf->ftSize->metrics.y_ppem tall

		glyph.imageHeight = scaled_height;
		glyph.imageWidth = scaled_width;
		glyph.s = (float)*xOut / 256;
		glyph.t = (float)*yOut / 256;
		glyph.s2 = glyph.s + (float)scaled_width / 256;
		glyph.t2 = glyph.t + (float)scaled_height / 256;

		*xOut += scaled_width + 1;
	}

	Mem_Free(bitmap->buffer);
	Mem_Free(bitmap);

	return &glyph;
}

#endif

static int fdOffset;
static byte* fdFile;

/*
============
readInt
============
*/
int readInt(void) {
	int i = fdFile[fdOffset] + (fdFile[fdOffset + 1] << 8) + (fdFile[fdOffset + 2] << 16) + (fdFile[fdOffset + 3] << 24);
	fdOffset += 4;
	return i;
}

/*
============
readFloat
============
*/
float readFloat(void) {
	float f;
	memcpy(&f, &fdFile[fdOffset], sizeof(float));
	fdOffset += sizeof(float);
	return LittleFloat(f);
}

/*
============
RegisterFont

Loads 3 point sizes, 12, 24, and 48
============
*/
bool idRenderSystemLocal::RegisterFont(const char* fontName, fontInfoEx_t& font) {
#ifdef BUILD_FREETYPE
	FT_Face face;
	int j, k, xOut, yOut, lastStart, imageNumber;
	int scaledSize, newSize, maxHeight, left, satLevels;
	unsigned char* out, * imageBuff;
	glyphInfo_t* glyph;
	idImage* image;
	idMaterial* h;
	float max;
#endif
	void* faceData;
	ID_TIME_T ftime;
	int i, len, fontCount;
	char name[1024];

	int pointSize = 12;
	/*
		if ( registeredFontCount >= MAX_FONTS ) {
			common->Warning( "RegisterFont: Too many fonts registered already." );
			return false;
		}

		int pointSize = 12;
		idStr::snPrintf( name, sizeof(name), "%s/fontImage_%i.dat", fontName, pointSize );
		for ( i = 0; i < registeredFontCount; i++ ) {
			if ( idStr::Icmp(name, registeredFont[i].fontInfoSmall.name) == 0 ) {
				memcpy( &font, &registeredFont[i], sizeof( fontInfoEx_t ) );
				return true;
			}
		}
	*/
	assert(sizeof(float) == 4 && "if this is false, readFloat() won't work");

	memset(&font, 0, sizeof(font));

	for (fontCount = 0; fontCount < 3; fontCount++) {

		if (fontCount == 0) {
			pointSize = 12;
		}
		else if (fontCount == 1) {
			pointSize = 24;
		}
		else {
			pointSize = 48;
		}
		// we also need to adjust the scale based on point size relative to 48 points as the ui scaling is based on a 48 point font
		float glyphScale = 1.0f;		// change the scale to be relative to 1 based on 72 dpi ( so dpi of 144 means a scale of .5 )
		glyphScale *= 48.0f / pointSize;

		idStr::snPrintf(name, sizeof(name), "%s/fontImage_%i.dat", fontName, pointSize);

		fontInfo_t* outFont;
		if (fontCount == 0) {
			outFont = &font.fontInfoSmall;
		}
		else if (fontCount == 1) {
			outFont = &font.fontInfoMedium;
		}
		else {
			outFont = &font.fontInfoLarge;
		}

		idStr::Copynz(outFont->name, name, sizeof(outFont->name));

		len = fileSystem->ReadFile(name, NULL, &ftime);
		if (len != FILESIZE_fontInfo_t) {
			common->Warning("RegisterFont: couldn't find font: '%s'", name);
			return false;
		}

		fileSystem->ReadFile(name, &faceData, &ftime);
		fdOffset = 0;
		fdFile = reinterpret_cast<unsigned char*>(faceData);
		for (i = 0; i < GLYPHS_PER_FONT; i++) {
			outFont->glyphs[i].height = readInt();
			outFont->glyphs[i].top = readInt();
			outFont->glyphs[i].bottom = readInt();
			outFont->glyphs[i].pitch = readInt();
			outFont->glyphs[i].xSkip = readInt();
			outFont->glyphs[i].imageWidth = readInt();
			outFont->glyphs[i].imageHeight = readInt();
			outFont->glyphs[i].s = readFloat();
			outFont->glyphs[i].t = readFloat();
			outFont->glyphs[i].s2 = readFloat();
			outFont->glyphs[i].t2 = readFloat();
			/* font.glyphs[i].glyph			= */ readInt();
			//FIXME: the +6, -6 skips the embedded fonts/
			memcpy(outFont->glyphs[i].shaderName, &fdFile[fdOffset + 6], 32 - 6);
			fdOffset += 32;
		}
		outFont->glyphScale = readFloat();

		int mw = 0;
		int mh = 0;
		for (i = GLYPH_START; i < GLYPH_END; i++) {
			idStr::snPrintf(name, sizeof(name), "%s/%s", fontName, outFont->glyphs[i].shaderName);
			outFont->glyphs[i].glyph = declManager->FindMaterial(name);
			outFont->glyphs[i].glyph->SetSort(SS_GUI);
			if (mh < outFont->glyphs[i].height) {
				mh = outFont->glyphs[i].height;
			}
			if (mw < outFont->glyphs[i].xSkip) {
				mw = outFont->glyphs[i].xSkip;
			}
		}
		if (fontCount == 0) {
			font.maxWidthSmall = mw;
			font.maxHeightSmall = mh;
		}
		else if (fontCount == 1) {
			font.maxWidthMedium = mw;
			font.maxHeightMedium = mh;
		}
		else {
			font.maxWidthLarge = mw;
			font.maxHeightLarge = mh;
		}
		fileSystem->FreeFile(faceData);
	}

	//memcpy( &registeredFont[registeredFontCount++], &font, sizeof( fontInfoEx_t ) );

	return true;

#ifndef BUILD_FREETYPE
	common->Warning("RegisterFont: couldn't load FreeType code %s", name);
#else

	if (ftLibrary == NULL) {
		common->Warning("RegisterFont: FreeType not initialized.");
		return;
	}

	len = fileSystem->ReadFile(fontName, &faceData, &ftime);
	if (len <= 0) {
		common->Warning("RegisterFont: Unable to read font file");
		return;
	}

	// allocate on the stack first in case we fail
	if (FT_New_Memory_Face(ftLibrary, faceData, len, 0, &face)) {
		common->Warning("RegisterFont: FreeType2, unable to allocate new face.");
		return;
	}


	if (FT_Set_Char_Size(face, pointSize << 6, pointSize << 6, dpi, dpi)) {
		common->Warning("RegisterFont: FreeType2, Unable to set face char size.");
		return;
	}

	// font = registeredFonts[registeredFontCount++];

	// make a 256x256 image buffer, once it is full, register it, clean it and keep going
	// until all glyphs are rendered

	out = Mem_Alloc(1024 * 1024);
	if (out == NULL) {
		common->Warning("RegisterFont: Mem_Alloc failure during output image creation.");
		return;
	}
	memset(out, 0, 1024 * 1024);

	maxHeight = 0;

	for (i = GLYPH_START; i < GLYPH_END; i++) {
		glyph = RE_ConstructGlyphInfo(out, &xOut, &yOut, &maxHeight, face, (unsigned char)i, qtrue);
	}

	xOut = 0;
	yOut = 0;
	i = GLYPH_START;
	lastStart = i;
	imageNumber = 0;

	while (i <= GLYPH_END) {

		glyph = RE_ConstructGlyphInfo(out, &xOut, &yOut, &maxHeight, face, (unsigned char)i, qfalse);

		if (xOut == -1 || yOut == -1 || i == GLYPH_END) {
			// ran out of room
			// we need to create an image from the bitmap, set all the handles in the glyphs to this point
			//

			scaledSize = 256 * 256;
			newSize = scaledSize * 4;
			imageBuff = Mem_Alloc(newSize);
			left = 0;
			max = 0;
			satLevels = 255;
			for (k = 0; k < (scaledSize); k++) {
				if (max < out[k]) {
					max = out[k];
				}
			}

			if (max > 0) {
				max = 255 / max;
			}

			for (k = 0; k < (scaledSize); k++) {
				imageBuff[left++] = 255;
				imageBuff[left++] = 255;
				imageBuff[left++] = 255;
				imageBuff[left++] = ((float)out[k] * max);
			}

			idStr::snprintf(name, sizeof(name), "fonts/fontImage_%i_%i.tga", imageNumber++, pointSize);
			if (r_saveFontData->integer) {
				R_WriteTGA(name, imageBuff, 256, 256);
			}

			//idStr::snprintf( name, sizeof(name), "fonts/fontImage_%i_%i", imageNumber++, pointSize );
			image = R_CreateImage(name, imageBuff, 256, 256, qfalse, qfalse, GL_CLAMP);
			h = RE_RegisterShaderFromImage(name, LIGHTMAP_2D, image, qfalse);
			for (j = lastStart; j < i; j++) {
				font.glyphs[j].glyph = h;
				idStr::Copynz(font.glyphs[j].shaderName, name, sizeof(font.glyphs[j].shaderName));
			}
			lastStart = i;
			memset(out, 0, 1024 * 1024);
			xOut = 0;
			yOut = 0;
			Mem_Free(imageBuff);
			i++;
		}
		else {
			memcpy(&font.glyphs[i], glyph, sizeof(glyphInfo_t));
			i++;
		}
	}

	registeredFont[registeredFontCount].glyphScale = glyphScale;
	font.glyphScale = glyphScale;
	memcpy(&registeredFont[registeredFontCount++], &font, sizeof(fontInfo_t));

	if (r_saveFontData->integer) {
		common->Warning("FIXME: font saving doesnt respect alignment!");
		fileSystem->WriteFile(va("fonts/fontImage_%i.dat", pointSize), &font, sizeof(fontInfo_t));
	}

	Mem_Free(out);

	fileSystem->FreeFile(faceData);
#endif
	return true;
}

/*
============
R_InitFreeType
============
*/
void R_InitFreeType(void) {
#ifdef BUILD_FREETYPE
	if (FT_Init_FreeType(&ftLibrary)) {
		common->Printf("R_InitFreeType: Unable to initialize FreeType.\n");
	}
#endif
	//	registeredFontCount = 0;
}

/*
============
R_DoneFreeType
============
*/
void R_DoneFreeType(void) {
#ifdef BUILD_FREETYPE
	if (ftLibrary) {
		FT_Done_FreeType(ftLibrary);
		ftLibrary = NULL;
	}
#endif
	//	registeredFontCount = 0;
}