462 lines
16 KiB
C++
462 lines
16 KiB
C++
#include "ttf_internal.h"
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#include <string_utils.h>
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#include <memory/heap.h>
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#include <serial.h>
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// 大端读取器（TTF 为大端格式）
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static inline SUINT16 rd16(const SUINT8* p) {
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return ((SUINT16)p[0] << 8) | p[1];
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}
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static inline SSINT16 rd16s(const SUINT8* p) {
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return (SSINT16)(((SUINT16)p[0] << 8) | p[1]);
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}
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static inline SUINT32 rd32(const SUINT8* p) {
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return ((SUINT32)p[0] << 24) | ((SUINT32)p[1] << 16) |
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((SUINT32)p[2] << 8) | (SUINT32)p[3];
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}
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static const SUINT8* find_table(ttf_face_t* face, const char tag[4]) {
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for (SUINT16 i = 0; i < face->num_tables; i++) {
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if (face->tables[i].tag[0] == tag[0] &&
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face->tables[i].tag[1] == tag[1] &&
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face->tables[i].tag[2] == tag[2] &&
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face->tables[i].tag[3] == tag[3]) {
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return face->data + face->tables[i].offset;
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}
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}
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return NULL;
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}
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// UTF-8 解码
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SSINT32 ttf_utf8_decode(const char** p) {
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const SUINT8* s = (const SUINT8*)*p;
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SUINT8 b0 = s[0];
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if (b0 < 0x80) { (*p)++; return b0; }
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if ((b0 & 0xE0) == 0xC0) { (*p) += 2; return ((b0 & 0x1F) << 6) | (s[1] & 0x3F); }
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if ((b0 & 0xF0) == 0xE0) { (*p) += 3; return ((b0 & 0x0F) << 12) | ((s[1] & 0x3F) << 6) | (s[2] & 0x3F); }
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if ((b0 & 0xF8) == 0xF0) { (*p) += 4; return ((b0 & 0x07) << 18) | ((s[1] & 0x3F) << 12) | ((s[2] & 0x3F) << 6) | (s[3] & 0x3F); }
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(*p)++;
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return -1;
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}
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// cmap 子表查找
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static const SUINT8* find_cmap_subtable(ttf_face_t* face) {
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const SUINT8* cmap = face->cmap;
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SUINT16 num = rd16(cmap + 2);
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const SUINT8* best = NULL;
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SSINT32 best_score = -1;
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for (SUINT16 i = 0; i < num; i++) {
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const SUINT8* rec = cmap + 4 + i * 8;
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SUINT16 platform = rd16(rec + 0);
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SUINT16 encoding = rd16(rec + 2);
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SUINT32 offset = rd32(rec + 4);
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SSINT32 score = -1;
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if (platform == 3 && encoding == 10) score = 30;
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else if (platform == 3 && encoding == 1) score = 20;
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else if (platform == 0 && encoding == 4) score = 10;
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else if (platform == 0 && encoding == 3) score = 5;
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if (score > best_score) { best_score = score; best = cmap + offset; }
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}
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return best;
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}
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static SUINT16 cmap4_lookup(const SUINT8* sub, SSINT32 cp) {
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SUINT16 segCountX2 = rd16(sub + 6);
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SUINT16 segCount = segCountX2 / 2;
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const SUINT8* endCode = sub + 14;
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const SUINT8* startCode = endCode + segCountX2 + 2;
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const SUINT8* idDelta = startCode + segCountX2;
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const SUINT8* idRangeOff = idDelta + segCountX2;
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for (SUINT16 i = 0; i < segCount; i++) {
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SUINT16 ec = rd16(endCode + i * 2);
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SUINT16 sc = rd16(startCode + i * 2);
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if (cp < sc) break;
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if (cp <= ec) {
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SUINT16 dro = rd16(idRangeOff + i * 2);
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if (dro == 0) {
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return (SUINT16)((SSINT16)cp + (SSINT16)rd16(idDelta + i * 2));
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}
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SUINT16 gidx = rd16(idRangeOff + i * 2 + dro + (cp - sc) * 2);
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if (gidx == 0) return 0;
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return (SUINT16)((SSINT16)gidx + (SSINT16)rd16(idDelta + i * 2));
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}
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}
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return 0;
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}
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static SUINT16 cmap12_lookup(const SUINT8* sub, SSINT32 cp) {
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// Format 12 头：format(2) reserved(2) length(4) language(4) nGroups(4)
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SUINT32 nGroups = rd32(sub + 12);
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const SUINT8* g = sub + 16;
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for (SUINT32 i = 0; i < nGroups; i++) {
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SUINT32 sc = rd32(g + 0);
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SUINT32 ec = rd32(g + 4);
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SUINT32 sG = rd32(g + 8);
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if (cp < (SSINT32)sc) break;
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if (cp <= (SSINT32)ec) return (SUINT16)(sG + (cp - sc));
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g += 12;
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}
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return 0;
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}
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SUINT16 ttf_cmap_lookup(ttf_face_t* face, SSINT32 cp) {
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const SUINT8* sub = find_cmap_subtable(face);
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if (!sub) return 0;
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SUINT16 fmt = rd16(sub);
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if (fmt == 4) return cmap4_lookup(sub, cp);
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if (fmt == 12) return cmap12_lookup(sub, cp);
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return 0;
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}
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// glyf 解码
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bool ttf_load_glyph(ttf_face_t* face, SUINT16 glyph_id,
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SUINT32 pixel_size_px, ttf_outline_t* out)
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{
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mem_set(out, 0, sizeof(*out));
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if (glyph_id >= face->num_glyphs) return false;
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// Loca 索引
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SUINT32 off0, off1;
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if (face->index_to_loc_format == 0) {
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off0 = ((SUINT32)rd16(face->loca + glyph_id * 2)) * 2;
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off1 = ((SUINT32)rd16(face->loca + (glyph_id + 1) * 2)) * 2;
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} else {
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off0 = rd32(face->loca + glyph_id * 4);
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off1 = rd32(face->loca + (glyph_id + 1) * 4);
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}
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if (off0 >= face->glyf_len) return false;
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// 进宽（始终从 hmtx 读取，无论 glyf 是否存在）
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{
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SUINT16 aw;
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if (glyph_id < face->num_long_hor_metrics) {
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aw = rd16(face->hmtx + glyph_id * 4);
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} else {
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aw = rd16(face->hmtx + (face->num_long_hor_metrics - 1) * 4);
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}
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out->advance = (f26_6)(((SUINT64)aw * (SUINT64)pixel_size_px * 64) / face->units_per_em);
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}
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if (off0 == off1) {
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// 空白字形（如空格）
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return true;
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}
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const SUINT8* g = face->glyf + off0;
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SSINT16 numContours = rd16s(g + 0);
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if (numContours < 0) {
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// 复合字形 — 解析组件记录并合并轮廓
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const SUINT8* cp = g + 10;
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SSINT32 all_xmin = 0x7FFFFFFF, all_ymin = 0x7FFFFFFF;
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SSINT32 all_xmax = -0x7FFFFFFF, all_ymax = -0x7FFFFFFF;
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// 复合字形标志（OpenType 规范）：
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// 0x0001 = ARG_1_AND_2_ARE_WORDS（16 位参数；否则 8 位）
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// 0x0002 = ARGS_ARE_XY_VALUES（偏移量；否则点索引）
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// 0x0008 = WE_HAVE_A_SCALE
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// 0x0040 = WE_HAVE_A_2x2
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// 0x0080 = WE_HAVE_AN_X_AND_Y_SCALE
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// 0x0020 = MORE_COMPONENTS
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for (;;) {
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SUINT16 comp_flags = rd16(cp); cp += 2;
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SUINT16 comp_glyph = rd16(cp); cp += 2;
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// 读取参数（大小取决于 ARG_1_AND_2_ARE_WORDS）
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SSINT32 arg1, arg2;
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if (comp_flags & 0x0001) {
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// 16 位有符号字
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arg1 = rd16s(cp); cp += 2;
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arg2 = rd16s(cp); cp += 2;
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} else {
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// 8 位有符号字节
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arg1 = (SSINT8)cp[0];
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arg2 = (SSINT8)cp[1];
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cp += 2;
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}
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// 如果存在则读取缩放比例
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f26_6 scale = F26_ONE;
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if (comp_flags & 0x0008) {
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// WE_HAVE_A_SCALE：16.16 定点数
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SSINT16 s16 = rd16s(cp); cp += 2;
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scale = (f26_6)s16; // already in f26.6 from 16.16
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}
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// 如果存在则读取 x/y 缩放
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f26_6 scaleX = F26_ONE, scaleY = F26_ONE;
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if (comp_flags & 0x0080) {
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// WE_HAVE_AN_X_AND_Y_SCALE：两个 16.16 值
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SSINT16 sx16 = rd16s(cp); cp += 2;
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SSINT16 sy16 = rd16s(cp); cp += 2;
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scaleX = (f26_6)sx16;
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scaleY = (f26_6)sy16;
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}
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// 如果存在则读取 2x2 矩阵
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f26_6 m00 = F26_ONE, m01 = 0, m10 = 0, m11 = F26_ONE;
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if (comp_flags & 0x0040) {
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// WE_HAVE_A_2x2：四个 2.14 值
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SSINT16 a = rd16s(cp); cp += 2;
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SSINT16 b = rd16s(cp); cp += 2;
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SSINT16 c = rd16s(cp); cp += 2;
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SSINT16 d = rd16s(cp); cp += 2;
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m00 = (f26_6)(a >> 8); // 2.14 -> 26.6: shift right 8
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m01 = (f26_6)(b >> 8);
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m10 = (f26_6)(c >> 8);
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m11 = (f26_6)(d >> 8);
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}
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// 加载组件字形
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ttf_outline_t comp;
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if (!ttf_load_glyph(face, comp_glyph, pixel_size_px, &comp))
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return false;
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// 判断参数是偏移量（XY 值）还是点索引
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SSINT32 offset_x = 0, offset_y = 0;
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if (comp_flags & 0x0002) {
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// ARGS_ARE_XY_VALUES：参数是像素偏移量（已缩放）
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// 从字体单位缩放到像素空间
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offset_x = (SSINT32)(((SSINT64)arg1 * (SSINT64)pixel_size_px * 64 / face->units_per_em));
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offset_y = (SSINT32)(((SSINT64)arg2 * (SSINT64)pixel_size_px * 64 / face->units_per_em));
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}
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// 变换并合并组件点
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for (SUINT16 i = 0; i < comp.num_points; i++) {
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f26_6 fx = comp.x[i];
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f26_6 fy = comp.y[i];
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f26_6 tx, ty;
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if (comp_flags & 0x0040) {
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// 2x2 矩阵变换
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tx = f26_mul(m00, fx) + f26_mul(m01, fy);
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ty = f26_mul(m10, fx) + f26_mul(m11, fy);
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} else if (comp_flags & 0x0008) {
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// 均匀缩放
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tx = f26_mul(scale, fx);
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ty = f26_mul(scale, fy);
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} else if (comp_flags & 0x0080) {
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// x/y 独立缩放
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tx = f26_mul(scaleX, fx);
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ty = f26_mul(scaleY, fy);
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} else {
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tx = fx;
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ty = fy;
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}
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f26_6 final_x = tx + offset_x;
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f26_6 final_y = ty + offset_y;
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out->x[out->num_points] = final_x;
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out->y[out->num_points] = final_y;
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out->on_curve[out->num_points] = comp.on_curve[i];
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out->num_points++;
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if (out->num_points > 1024) return false;
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SSINT32 xi = F26_FLOOR(final_x);
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SSINT32 yi = F26_FLOOR(final_y);
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if (xi < all_xmin) all_xmin = xi;
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if (xi > all_xmax) all_xmax = xi;
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if (yi < all_ymin) all_ymin = yi;
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if (yi > all_ymax) all_ymax = yi;
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}
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for (SUINT16 i = 0; i < comp.num_contours; i++) {
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if (out->num_contours >= 64) return false;
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out->first[out->num_contours] = (SUINT16)(out->num_points - comp.num_points + comp.first[i]);
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out->last[out->num_contours] = (SUINT16)(out->num_points - comp.num_points + comp.last[i]);
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out->num_contours++;
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}
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if (!(comp_flags & 0x0020)) break; // no more components
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}
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if (out->num_points == 0) return true;
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out->xmin = all_xmin;
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out->ymin = all_ymin;
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out->xmax = all_xmax;
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out->ymax = all_ymax;
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return true;
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}
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if (numContours == 0) return true;
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if (numContours > 64) return false;
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SSINT16 gxMin = rd16s(g + 2);
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SSINT16 gyMin = rd16s(g + 4);
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SSINT16 gxMax = rd16s(g + 6);
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SSINT16 gyMax = rd16s(g + 8);
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const SUINT8* p = g + 10;
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SUINT16 endPts[64];
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for (SSINT16 i = 0; i < numContours; i++) { endPts[i] = rd16(p); p += 2; }
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SUINT16 numPoints = (SUINT16)(endPts[numContours - 1] + 1);
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if (numPoints > 1024) return false;
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SUINT16 instrLen = rd16(p); p += 2;
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p += instrLen;
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// 解码标志（含 REPEAT）
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SUINT8 flags[1024];
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SUINT16 pi = 0;
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while (pi < numPoints) {
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SUINT8 f = *p++;
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flags[pi++] = f;
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if (f & 0x08) {
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SUINT8 rep = *p++;
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for (SUINT16 k = 1; k <= rep && pi < numPoints; k++)
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flags[pi++] = f;
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}
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}
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// 解码 x 坐标到 x_raw[]
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SSINT32 x_raw[1024];
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{
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SSINT32 x = 0;
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for (SUINT16 i = 0; i < numPoints; i++) {
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SUINT8 f = flags[i];
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if (f & 0x02) {
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SUINT8 b = *p++;
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x += (f & 0x10) ? b : -(SSINT32)b;
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} else if (!(f & 0x10)) {
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x += (SSINT16)((SUINT16)p[0] << 8 | p[1]);
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p += 2;
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}
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x_raw[i] = x;
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}
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}
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// 解码 y 坐标到 y_raw[]
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SSINT32 y_raw[1024];
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{
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SSINT32 y = 0;
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for (SUINT16 i = 0; i < numPoints; i++) {
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SUINT8 f = flags[i];
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if (f & 0x04) {
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SUINT8 b = *p++;
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y += (f & 0x20) ? b : -(SSINT32)b;
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} else if (!(f & 0x20)) {
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y += (SSINT16)((SUINT16)p[0] << 8 | p[1]);
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p += 2;
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}
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y_raw[i] = y;
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}
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}
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// 缩放到像素空间（f26_6）
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SUINT64 scale_num = (SUINT64)pixel_size_px * 64;
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for (SUINT16 i = 0; i < numPoints; i++) {
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out->x[i] = (f26_6)(((SSINT64)x_raw[i] * (SSINT64)scale_num) / face->units_per_em);
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out->y[i] = (f26_6)(((SSINT64)y_raw[i] * (SSINT64)scale_num) / face->units_per_em);
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out->on_curve[i] = (flags[i] & 0x01) ? 1 : 0;
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}
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out->num_contours = (SUINT16)numContours;
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out->num_points = numPoints;
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SUINT16 start = 0;
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for (SSINT16 i = 0; i < numContours; i++) {
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out->first[i] = start;
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out->last[i] = endPts[i];
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start = endPts[i] + 1;
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}
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out->xmin = (SSINT32)(((SSINT64)gxMin * (SSINT64)scale_num) / face->units_per_em);
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out->ymin = (SSINT32)(((SSINT64)gyMin * (SSINT64)scale_num) / face->units_per_em);
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out->xmax = (SSINT32)(((SSINT64)gxMax * (SSINT64)scale_num) / face->units_per_em);
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out->ymax = (SSINT32)(((SSINT64)gyMax * (SSINT64)scale_num) / face->units_per_em);
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return true;
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}
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// 打开 / 关闭
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ttf_face_t* ttf_open(const void* data, UINTN size) {
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if (!data || size < 12) return NULL;
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const SUINT8* d = (const SUINT8*)data;
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SUINT32 sfVersion = rd32(d);
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if (sfVersion != 0x00010000 && sfVersion != 0x74727565) {
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serial_write("ttf: bad sfVersion\n");
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return NULL;
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}
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SUINT16 numTables = rd16(d + 4);
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if (numTables == 0 || numTables > 32) return NULL;
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ttf_face_t* face = (ttf_face_t*)kcalloc(1, sizeof(ttf_face_t));
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if (!face) return NULL;
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face->data = d;
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face->size = size;
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face->num_tables = numTables;
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for (SUINT16 i = 0; i < numTables; i++) {
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const SUINT8* r = d + 12 + i * 16;
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face->tables[i].tag[0] = r[0];
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face->tables[i].tag[1] = r[1];
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face->tables[i].tag[2] = r[2];
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face->tables[i].tag[3] = r[3];
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face->tables[i].offset = rd32(r + 8);
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face->tables[i].length = rd32(r + 12);
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}
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const SUINT8* head = find_table(face, "head");
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if (!head) { kfree(face); return NULL; }
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face->units_per_em = rd16(head + 18);
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face->index_to_loc_format = rd16s(head + 50);
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const SUINT8* hhea = find_table(face, "hhea");
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if (!hhea) { kfree(face); return NULL; }
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face->hhea_ascender = rd16s(hhea + 4);
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face->hhea_descender = rd16s(hhea + 6);
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face->hhea_line_gap = rd16s(hhea + 8);
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face->num_long_hor_metrics = rd16(hhea + 34);
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const SUINT8* maxp = find_table(face, "maxp");
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||
if (!maxp) { kfree(face); return NULL; }
|
||
face->num_glyphs = rd16(maxp + 4);
|
||
face->max_points = rd16(maxp + 6);
|
||
face->max_contours = rd16(maxp + 8);
|
||
|
||
const SUINT8* os2 = find_table(face, "OS/2");
|
||
if (os2) {
|
||
face->os2_ascender = rd16s(os2 + 68);
|
||
face->os2_descender = rd16s(os2 + 70);
|
||
face->os2_line_gap = rd16s(os2 + 72);
|
||
} else {
|
||
face->os2_ascender = face->hhea_ascender;
|
||
face->os2_descender = face->hhea_descender;
|
||
face->os2_line_gap = face->hhea_line_gap;
|
||
}
|
||
|
||
const SUINT8* loca = find_table(face, "loca");
|
||
const SUINT8* glyf = find_table(face, "glyf");
|
||
const SUINT8* hmtx = find_table(face, "hmtx");
|
||
if (!loca || !glyf || !hmtx) { kfree(face); return NULL; }
|
||
face->loca = loca;
|
||
face->glyf = glyf;
|
||
face->hmtx = hmtx;
|
||
for (SUINT16 i = 0; i < numTables; i++) {
|
||
if (face->tables[i].tag[0]=='g'&&face->tables[i].tag[1]=='l'&&
|
||
face->tables[i].tag[2]=='y'&&face->tables[i].tag[3]=='f')
|
||
face->glyf_len = face->tables[i].length;
|
||
if (face->tables[i].tag[0]=='h'&&face->tables[i].tag[1]=='m'&&
|
||
face->tables[i].tag[2]=='t'&&face->tables[i].tag[3]=='x')
|
||
face->hmtx_len = face->tables[i].length;
|
||
}
|
||
|
||
face->cmap = find_table(face, "cmap");
|
||
if (!face->cmap) { kfree(face); return NULL; }
|
||
|
||
return face;
|
||
}
|
||
|
||
void ttf_close(ttf_face_t* face) {
|
||
if (face) kfree(face);
|
||
}
|
||
|
||
// 度量值（缩放到 pixel_size，返回 26.6 定点数）
|
||
SSINT32 ttf_ascender (ttf_face_t* face, SUINT32 px) {
|
||
return (SSINT32)(((SSINT64)face->os2_ascender * (SSINT64)px * 64) / face->units_per_em);
|
||
}
|
||
SSINT32 ttf_descender(ttf_face_t* face, SUINT32 px) {
|
||
return (SSINT32)(((SSINT64)face->os2_descender * (SSINT64)px * 64) / face->units_per_em);
|
||
}
|
||
SSINT32 ttf_line_gap (ttf_face_t* face, SUINT32 px) {
|
||
return (SSINT32)(((SSINT64)face->os2_line_gap * (SSINT64)px * 64) / face->units_per_em);
|
||
}
|