52 lines
1.6 KiB
C
52 lines
1.6 KiB
C
/* deshab/font.h - ASCII 位图字体渲染
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*
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* 整合 desktop_app.h 的 da_draw_char/draw_string，统一前缀为 dsb_。
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*
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* 前置条件：包含者需先提供位图数据源。两种方式：
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* 1. #include "ascii_bitmaps.c"（定义 static g_ascii/g_ascii_w/g_ascii_h）
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* 2. 自行定义 const u8 *g_ascii[95]; i64 g_ascii_w, g_ascii_h;
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* 再 #include "font.h"。
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*
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* 与 deshab_ui.h 使用相同的包含顺序约定。
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*/
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#ifndef DESHAB_FONT_H
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#define DESHAB_FONT_H
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#include "types.h"
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#include "app.h"
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#include "fb.h"
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/* 由包含者在 include 本头前提供：
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* static const u8 *g_ascii[95]; // 95 字符 ' '..'~'
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* static i64 g_ascii_w, g_ascii_h;
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*/
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static inline void dsb_draw_char(dsb_app_context *ac, char ch, i64 x, i64 y, u32 fg, u32 bg) {
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u32 idx = (u32)(ch - ' ');
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if (idx > 94) idx = 0;
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const u8 *glyph = g_ascii[idx];
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i64 gw = g_ascii_w, gh = g_ascii_h;
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for (i64 r = 0; r < gh; r++) {
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i64 yy = y + r;
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if (yy < 0 || (u64)yy >= ac->fb_h) continue;
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u32 *line = (u32 *)((u8 *)ac->fb + (u64)yy * ac->fb_pitch);
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for (i64 c = 0; c < gw; c++) {
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u8 a = glyph[r * gw + c];
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if (a == 0) continue;
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i64 xx = x + c;
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if (xx < 0 || (u64)xx >= ac->fb_w) continue;
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line[xx] = (a == 255) ? fg : dsb_blend(bg, fg, a);
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}
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}
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}
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static inline void dsb_draw_string(dsb_app_context *ac, const char *s, i64 x, i64 y, u32 fg, u32 bg, i64 step) {
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i64 cx = x;
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while (*s) {
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dsb_draw_char(ac, *s, cx, y, fg, bg);
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cx += step;
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s++;
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}
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}
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#endif /* DESHAB_FONT_H */
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