207 lines
6.8 KiB
C
207 lines
6.8 KiB
C
/* zhfont.c — 中文位图字库加载与渲染实现
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*
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* .dbf 格式（见 ../font/dbf.h）：
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* header 14 字节 + count*12 字节索引（按 Unicode 码点升序）+ 字形数据。
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* 索引项 data_offset 相对文件头。
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*
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* 渲染：8bpp 灰度字形逐像素 du_blend（与 ASCII 渲染同路径，无字体缓存，
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* 每屏 <500 字在性能预算内，见桌面重构计划第七节）。
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*/
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/* 顺序敏感：ascii_font.h 声明 g_ascii（deshab_ui.h 的 du_draw_char 引用） */
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#include "ascii_font.h"
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#include "zhfont.h"
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#include "../font/dbf.h"
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typedef unsigned char u8;
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typedef unsigned short u16;
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typedef unsigned int u32;
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typedef unsigned long long u64;
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typedef long long i64;
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/* ---- 字库状态 ---- */
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static zhfont_read_fn g_zh_read = 0;
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static const u8 *g_zh16 = 0;
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static const u8 *g_zh24 = 0;
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/* ---- dbf 访问 ---- */
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static const u8 *zh_dbf_get(const u8 *font, u32 cp, int *out_w, int *out_h) {
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const dbf_header *hdr = (const dbf_header *)font;
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const dbf_index_entry *idx = (const dbf_index_entry *)(font + 14);
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if (cp > 0xFFFF) return 0;
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int i = dbf_lookup((dbf_index_entry *)idx, hdr->count, (u16)cp);
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if (i < 0) return 0;
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*out_w = idx[i].width;
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*out_h = hdr->height;
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return font + idx[i].offset;
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}
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/* 缺字占位：1px 空框 */
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static int zh_draw_missing(du_context *ctx, i64 x, i64 y, int w, int h, u32 fg) {
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du_rect_outline(ctx, x, y, w, h, fg, 1);
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return w;
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}
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/* ---- 公开接口 ---- */
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/* 头部静态校验（magic / bpp / 尺寸字段），不依赖文件大小 */
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static int zh_dbf_valid(const u8 *dst) {
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const dbf_header *hdr = (const dbf_header *)dst;
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if (!dst) return -1;
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if (hdr->magic[0] != 'D' || hdr->magic[1] != 'B' ||
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hdr->magic[2] != 'F' || hdr->magic[3] != 0x10) return -2;
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if (hdr->bpp != 8) return -3;
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if (hdr->count == 0 || hdr->height == 0 || hdr->width == 0) return -4;
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return 0;
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}
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static int zh_load_dbf(const char *path, u8 *dst, u32 cap) {
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u32 sz = 0;
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if (!g_zh_read) return -1;
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if (g_zh_read(path, dst, cap, &sz) != 0) return -2;
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if (sz < 14) return -3;
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int rc = zh_dbf_valid(dst);
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if (rc != 0) return rc - 10;
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/* 越界防护：索引区与最大数据项必须在文件内 */
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{
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const dbf_header *hdr = (const dbf_header *)dst;
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const dbf_index_entry *last =
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(const dbf_index_entry *)(dst + 14 + (u64)(hdr->count - 1) * 12);
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if (14 + (u64)hdr->count * 12 > sz) return -7;
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if ((u64)last->offset + last->size > sz) return -8;
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}
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return 0;
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}
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int zhfont_init(zhfont_read_fn read_to) {
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int rc;
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g_zh_read = read_to;
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rc = zh_load_dbf("system/font/simhei_16.dbf",
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(u8 *)ZHFONT16_ADDR, ZHFONT16_MAX);
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if (rc != 0) {
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g_zh16 = 0;
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return rc; /* -1=无读取器 -2=FAT32读失败 -3=过小 -7/-8=越界 -11..-13=头校验 */
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}
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g_zh16 = (const u8 *)ZHFONT16_ADDR;
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return 0;
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}
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int zhfont_load24(void) {
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if (g_zh24) return 0;
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if (zh_load_dbf("system/font/simhei_24.dbf",
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(u8 *)ZHFONT24_ADDR, ZHFONT24_MAX) != 0) {
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return -1;
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}
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g_zh24 = (const u8 *)ZHFONT24_ADDR;
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return 0;
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}
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int zhfont_ok(void) { return g_zh16 != 0; }
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int zhfont_ok24(void) { return g_zh24 != 0; }
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void zhfont_attach16(const void *dbf_data) {
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/* 校验 magic 后挂接（数据由调用方保证生命周期） */
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if (dbf_data && zh_dbf_valid((const u8 *)dbf_data) == 0) g_zh16 = (const u8 *)dbf_data;
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else g_zh16 = 0;
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}
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void zhfont_attach24(const void *dbf_data) {
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if (dbf_data && zh_dbf_valid((const u8 *)dbf_data) == 0) g_zh24 = (const u8 *)dbf_data;
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else g_zh24 = 0;
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}
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unsigned int zh_utf8_decode(const char **s) {
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const u8 *p = (const u8 *)*s;
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u8 c = *p++;
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unsigned int cp;
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int extra;
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if (c < 0x80) { *s = (const char *)p; return c; }
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else if ((c & 0xE0) == 0xC0) { cp = c & 0x1F; extra = 1; }
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else if ((c & 0xF0) == 0xE0) { cp = c & 0x0F; extra = 2; }
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else if ((c & 0xF8) == 0xF0) { cp = c & 0x07; extra = 3; }
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else { (*s)++; return 0xFFFFFFFFu; } /* 无效首字节 */
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for (int i = 0; i < extra; i++) {
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u8 cc = *p;
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if ((cc & 0xC0) != 0x80) { (*s)++; return 0xFFFFFFFFu; }
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cp = (cp << 6) | (cc & 0x3F);
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p++;
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}
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*s = (const char *)p;
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return cp;
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}
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int zh_draw_char(du_context *ctx, unsigned int codepoint,
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i64 x, i64 y, unsigned int fg) {
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if (!g_zh16) {
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/* 字库未加载：ASCII 走 Consolas，其余画空框 */
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if (codepoint >= 0x20 && codepoint < 0x7F) {
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du_draw_char(ctx, (char)codepoint, x, y, fg, 0);
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return (int)DU_ASCII_STEP;
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}
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return 16;
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}
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if (codepoint < 0x20) return 4; /* 控制字符：窄空隙 */
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int w, h;
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const u8 *g = zh_dbf_get(g_zh16, codepoint, &w, &h);
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if (!g) return zh_draw_missing(ctx, x, y, 16, 16, fg);
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for (int r = 0; r < h; r++) {
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for (int c = 0; c < w; c++) {
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u8 a = g[r * w + c];
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if (!a) continue;
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du_u32 bg = du_pixel_read(ctx, x + c, y + r);
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du_pixel(ctx, x + c, y + r,
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(a == 255) ? fg : du_blend(bg, fg, a));
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}
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}
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return w;
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}
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int zh_string_width(const char *utf8, int size24) {
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int total = 0;
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const u8 *font = size24 ? g_zh24 : g_zh16;
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if (!utf8) return 0;
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while (*utf8) {
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unsigned int cp = zh_utf8_decode(&utf8);
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if (cp == 0xFFFFFFFFu) { total += 4; continue; }
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if (cp < 0x20) { total += 4; continue; }
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int w, h;
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const u8 *g = font ? zh_dbf_get(font, cp, &w, &h) : 0;
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if (!g) w = size24 ? 24 : 16;
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total += w + 1; /* 1px 字间距 */
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}
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return total > 0 ? total - 1 : 0;
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}
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int zh_line_height(int size24) { return size24 ? 26 : 18; }
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int zh_draw_string(du_context *ctx, const char *utf8,
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i64 x, i64 y, unsigned int fg, int size24) {
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const u8 *font = size24 ? g_zh24 : g_zh16;
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i64 cx = x;
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if (!utf8) return 0;
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while (*utf8) {
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unsigned int cp = zh_utf8_decode(&utf8);
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if (cp == 0xFFFFFFFFu) { cx += 4; continue; }
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if (cp < 0x20) { cx += 4; continue; }
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if (cp == 0x20) { cx += (size24 ? 18 : 12); continue; }
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int w, h;
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const u8 *g = font ? zh_dbf_get(font, cp, &w, &h) : 0;
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if (!g) {
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cx += zh_draw_missing(ctx, cx, y, size24 ? 24 : 16,
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size24 ? 24 : 16, fg) + 1;
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continue;
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}
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for (int r = 0; r < h; r++) {
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for (int c = 0; c < w; c++) {
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u8 a = g[r * w + c];
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if (!a) continue;
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du_u32 bg = du_pixel_read(ctx, cx + c, y + r);
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du_pixel(ctx, cx + c, y + r,
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(a == 255) ? fg : du_blend(bg, fg, a));
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}
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}
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cx += w + 1;
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}
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return (int)(cx - x);
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}
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