fatal: Implement basic text rendering.

stratosphere/fatal/source/fatal_font.cpp

@@ -0,0 +1,149 @@
+/*
+ * Copyright (c) 2018 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+ 
+
+#include <switch.h>
+#include "fatal_types.hpp"
+
+#include <cstring>
+#include <cstdlib>
+#include <cstdio>
+
+#include <ft2build.h>
+#include FT_FREETYPE_H
+
+#include "fatal_config.hpp"
+#include "fatal_font.hpp"
+
+static u16 *g_fb = nullptr;
+static u32 (*g_unswizzle_func)(u32, u32) = nullptr;
+static u16 g_font_color = 0xFFFF;
+
+static PlFontData g_font;
+static PlFontData g_fonts[PlSharedFontType_Total];
+static FT_Library g_library;
+static FT_Face g_face;
+static FT_Error g_ft_err = 0;
+
+static u16 Blend(u16 color, u16 bg, u8 alpha) {
+    const u32 c_r = RGB565_GET_R8(color);
+    const u32 c_g = RGB565_GET_G8(color);
+    const u32 c_b = RGB565_GET_B8(color);
+    const u32 b_r = RGB565_GET_R8(bg);
+    const u32 b_g = RGB565_GET_G8(bg);
+    const u32 b_b = RGB565_GET_B8(bg);
+    
+    const u32 r = ((alpha * c_r) + ((0xFF - alpha) * b_r)) / 0xFF;
+    const u32 g = ((alpha * c_g) + ((0xFF - alpha) * b_g)) / 0xFF;
+    const u32 b = ((alpha * c_b) + ((0xFF - alpha) * b_b)) / 0xFF;
+    
+    return RGB888_TO_RGB565(r, g, b);
+}
+
+static void DrawGlyph(FT_Bitmap *bitmap, u32 x, u32 y) {
+    u8* imageptr = bitmap->buffer;
+
+    if (bitmap->pixel_mode!=FT_PIXEL_MODE_GRAY) return;
+    
+    for (u32 tmpy = 0; tmpy < bitmap->rows; tmpy++) {
+        for (u32 tmpx = 0; tmpx < bitmap->width; tmpx++) {
+            /* Implement very simple blending, as the bitmap value is an alpha value. */
+            u16 *ptr = &g_fb[g_unswizzle_func(x + tmpx, y + tmpy)];
+            *ptr = Blend(g_font_color, *ptr, imageptr[tmpx]);
+        }
+        imageptr += bitmap->pitch;
+    }
+}
+
+void FontManager::DrawString(u32 x, u32 y, const char *str) {
+    FT_UInt glyph_index;
+    FT_GlyphSlot slot = g_face->glyph;
+    
+    const size_t len = strlen(str);
+    
+    u32 cur_x = x, cur_y = y;
+    
+    for (u32 i = 0; i < len; ) {
+        u32 cur_char;
+        ssize_t unit_count = decode_utf8(&cur_char, reinterpret_cast<const u8 *>(&str[i]));
+        if (unit_count <= 0) break;
+        i += unit_count;
+        
+        if (cur_char == '\n') {
+            cur_x = x;
+            cur_y += g_face->size->metrics.height >> 6;
+            continue;
+        }
+        
+        glyph_index = FT_Get_Char_Index(g_face, cur_char);
+        
+        g_ft_err = FT_Load_Glyph(g_face, glyph_index, FT_LOAD_DEFAULT);
+        
+        if (g_ft_err == 0) {
+            g_ft_err = FT_Render_Glyph(g_face->glyph, FT_RENDER_MODE_NORMAL);
+        }
+        
+        if (g_ft_err) {
+            return;
+        }
+        
+        DrawGlyph(&slot->bitmap, cur_x + slot->bitmap_left, cur_y - slot->bitmap_top);
+        
+        cur_x += slot->advance.x >> 6;
+        cur_y += slot->advance.y >> 6;
+    }
+}
+
+void FontManager::DrawFormat(u32 x, u32 y, const char *format, ...) {
+    va_list va_arg;
+    va_start(va_arg, format);
+    
+    char char_buf[0x400];
+    vsnprintf(char_buf, sizeof(char_buf), format, va_arg);
+    
+    DrawString(x, y, char_buf);
+}
+
+void FontManager::SetFontColor(u16 color) {
+    g_font_color = color;
+}
+
+void FontManager::ConfigureFontFramebuffer(u16 *fb, u32 (*unswizzle_func)(u32, u32)) {
+    g_fb = fb;
+    g_unswizzle_func = unswizzle_func;
+}
+
+Result FontManager::InitializeSharedFont() {
+    Result rc;
+    size_t total_fonts = 0;
+    
+    if (R_FAILED((rc = plGetSharedFont(GetFatalConfig()->language_code, g_fonts, PlSharedFontType_Total, &total_fonts)))) {
+        return rc;
+    }
+
+    if (R_FAILED((rc = plGetSharedFontByType(&g_font, PlSharedFontType_Standard)))) {
+        return rc;
+    }
+    
+    g_ft_err = FT_Init_FreeType(&g_library);
+    if (g_ft_err) return g_ft_err;
+    
+    g_ft_err = FT_New_Memory_Face(g_library, reinterpret_cast<const FT_Byte *>(g_font.address), g_font.size, 0, &g_face);
+    if (g_ft_err) return g_ft_err;
+    
+    g_ft_err = FT_Set_Char_Size(g_face, 0, 8*64, 300, 300);
+    return g_ft_err;
+}