1 files changed, 131 insertions, 46 deletions

diff --git a/src/text.h b/src/text.h
index f178608..3c0b3a8 100644
--- a/src/text.h
+++ b/src/text.h
@@ -5,7 +5,29 @@
 #include <stdio.h>
 
 #include "common.h"
-#include "bd-font.c"
+
+typedef enum {
+    TXT_MODE_TILED_BG,
+    TXT_MODE_MODE3,
+} TextMode;
+
+typedef struct Font {
+    // A pointer to an area of memory containing font data.
+    // TODO: Should we unpack each char everytime or unpack everything into RAM?
+    // Maybe this should be optional?
+    u32 *data;
+    // The char_map stores the index to the character position within the font
+    // array depending on the ascii number we want to render. This allows
+    // the usage reduced font sets, for example just uppercase letters and
+    // numbers.
+    u8 *char_map;
+    // Width and height of each font character. Only monospaced fonts are
+    // currently supported.
+    u8 char_width;
+    u8 char_height;
+    // The color of this font.
+    Color color;
+} Font;
 
 typedef struct TextEngine {
     // Currently working on tiled backgrounds only. The X and Y positions
@@ -13,14 +35,26 @@ typedef struct TextEngine {
     // For a 240x160 screen, we have 30x20 tiles available.
     size_t cursor_x;
     size_t cursor_y;
-    // Pointer to the screenblock being used for writing to the screen.
-    u16 *screenblock;
+    // Pointer to the memory being used for writing to the screen.
+    u16 *memory;
+    // TODO: Support other modes and monospaced fonts should be simple but we
+    // need to keep track of a couple of other variables, which may not be
+    // available for all modes. For example, tile modes can't have a font width
+    // smaller than the tile size, although bigger fonts (For example fonts
+    // composed of multiple tiles) should still be possible. This may not be
+    // a good time investment, but can be done in the future if needed.
+    // The mode controls how the text is rendered and how the memory is managed.
+    TextMode mode;
+    // The font used to render the text.
+    Font font;
 } TextEngine;
 
 static TextEngine text_engine = {0};
 
+static u8 default_char_map[256] = {0};
+
 void
-txt_putc(char c) {
+txt_putc_tile(char c) {
     if (c == '\0') {
         return;
     }
@@ -28,7 +62,7 @@ txt_putc(char c) {
         text_engine.cursor_x = 0;
         text_engine.cursor_y++;
     } else {
-        text_engine.screenblock[text_engine.cursor_x + 32 * text_engine.cursor_y] = c;
+        text_engine.memory[text_engine.cursor_x + 32 * text_engine.cursor_y] = c;
         text_engine.cursor_x++;
         if (text_engine.cursor_x >= 30) {
             text_engine.cursor_x = 0;
@@ -40,6 +74,52 @@ txt_putc(char c) {
     }
 }
 
+void
+txt_putc_m3(char c) {
+    if (c == '\0') {
+        return;
+    }
+    if (c == '\n') {
+        text_engine.cursor_x = 0;
+        text_engine.cursor_y += text_engine.font.char_height;
+    } else {
+        u8 idx = text_engine.font.char_map[c] * 2;
+        u32 *packed_char = text_engine.font.data;
+        packed_char += idx;
+        Tile tile = {0};
+        unpack_tiles(packed_char, &tile, 1);
+        int x = text_engine.cursor_x;
+        int y = text_engine.cursor_y;
+        for (size_t i = 0; i < text_engine.font.char_height; ++i) {
+            for (size_t j = 0; j < text_engine.font.char_width; ++j) {
+                if ((tile.row[i] >> 4 * j) & 0x1) {
+                    FRAMEBUFFER[y + i][x + j] = text_engine.font.color;
+                }
+            }
+        }
+        text_engine.cursor_x += text_engine.font.char_width;
+        if (text_engine.cursor_x >= SCREEN_WIDTH) {
+            text_engine.cursor_x = 0;
+            text_engine.cursor_y += text_engine.font.char_height;
+        }
+    }
+    if (text_engine.cursor_y >= SCREEN_HEIGHT) {
+        text_engine.cursor_y = 0;
+    }
+}
+
+void
+txt_putc(char c) {
+    switch (text_engine.mode) {
+        case TXT_MODE_TILED_BG: {
+            txt_putc_tile(c);
+        } break;
+        case TXT_MODE_MODE3: {
+            txt_putc_m3(c);
+        } break;
+    }
+}
+
 static inline void
 txt_puts(char *msg) {
     while (*msg) {
@@ -48,7 +128,7 @@ txt_puts(char *msg) {
 }
 
 void
-txt_init(size_t bg, Color clr, size_t cb_idx) {
+txt_init_tile(size_t bg, Font font, size_t cb_idx) {
     // The screenblock for the tile map should start after the tile memory
     // (MEM_VRAM + 0x2000 for 256 characters). Since each screenblock is
     // composed of 1024 screenblock entries of u16 (2 bytes), we need an
@@ -61,13 +141,48 @@ txt_init(size_t bg, Color clr, size_t cb_idx) {
     // Load font data in video memory. Each character is unpacked into a tile of
     // 8 32bit values (4bpp), meaning that for the full ASCII set of 256
     // characters, we need 8192 bytes of VRAM (8 * 4 * 256).
-    unpack_tiles(&bd_font, &TILE_MEM[cb_idx], 256);
+    text_engine.font = font;
+    unpack_tiles(font.data, &TILE_MEM[cb_idx], 256);
+
+    // Initialize default values.
+    if (font.color == 0) {
+        font.color = COLOR_WHITE;
+    }
 
     // Load palette color.
-    PAL_BUFFER_BG[1] = clr;
+    PAL_BUFFER_BG[1] = font.color;
 
     // Update text_engine variables.
-    text_engine.screenblock = SCREENBLOCK_MEM[sb_idx];
+    text_engine.memory = SCREENBLOCK_MEM[sb_idx];
+}
+
+void
+txt_init_bitmap(TextMode mode, Font font) {
+    // NOTE: Only mode 3 is currently supported
+    assert(mode == TXT_MODE_MODE3);
+
+    // If font_map is NULL, initialize the standard 0-255 character map.
+    if (font.char_map == NULL) {
+        for (size_t i = 0; i < 256; ++i) {
+            default_char_map[i] = i;
+        }
+        font.char_map = &default_char_map;
+    }
+
+    // Initialize default values if set to zero.
+    if (font.char_width == 0) {
+        font.char_width = 8;
+    }
+    if (font.char_height == 0) {
+        font.char_height = 8;
+    }
+    if (font.color == 0) {
+        font.color = COLOR_WHITE;
+    }
+
+    // Prepare text engine.
+    text_engine.font = font;
+    text_engine.mode = mode;
 }
 
 // Print text to the screen with formatting.
@@ -75,56 +190,26 @@ void
 txt_printf(char *msg, ...) {
     va_list arg_list;
     va_start(arg_list, msg);
-    char c;
-    while ((c = *msg++) != '\0') {
-        if (c != '%') {
-            txt_putc(c);
-            continue;
-        }
-        c = *msg++;
-        switch (c) {
-            case 's': {
-                txt_puts(va_arg(arg_list, char *));
-            } break;
-            case 'd': {
-                char buf[12] = {0};
-                int x = va_arg(arg_list, int);
-                sprintf(buf, "%d", x);
-                txt_puts(buf);
-            } break;
-            case 'u': {
-                char buf[12] = {0};
-                unsigned int x = va_arg(arg_list, unsigned int);
-                sprintf(buf, "%u", x);
-                txt_puts(buf);
-            } break;
-            case 'x': {
-                char buf[12] = {0};
-                unsigned int x = va_arg(arg_list, unsigned int);
-                sprintf(buf, "%x", x);
-                txt_puts(buf);
-            } break;
-            default: {
-                txt_putc('%');
-                txt_putc(c);
-            } break;
-        }
-    }
+    char buf[512] = {0};
+    vsprintf(buf, msg, arg_list);
+    txt_puts(buf);
 }
 
+// TODO: Update for working on bitmap modes.
 void
 txt_clear_line(void) {
     for (size_t i = 0; i < 30; ++i) {
-        text_engine.screenblock[i + 32 * text_engine.cursor_y] = ' ';
+        text_engine.memory[i + 32 * text_engine.cursor_y] = ' ';
     }
     text_engine.cursor_x = 0;
 }
 
+// TODO: Update for working on bitmap modes.
 void
 txt_clear_screen(void) {
     for (size_t j = 0; j < 20; ++j) {
         for (size_t i = 0; i < 30; ++i) {
-            text_engine.screenblock[i + 32 * j] = ' ';
+            text_engine.memory[i + 32 * j] = ' ';
         }
     }
     text_engine.cursor_x = 0;