P8SCII support, initial commit. #4, #12

Author: mupfdev

cmake/project_config.cmake

@@ -8,6 +8,7 @@ set(project_sources
   ${CMAKE_CURRENT_SOURCE_DIR}/src/core.c
   ${CMAKE_CURRENT_SOURCE_DIR}/src/image_loader.c
   ${CMAKE_CURRENT_SOURCE_DIR}/src/memory.c
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/p8scii.c
   ${CMAKE_CURRENT_SOURCE_DIR}/src/lexaloffle/p8_compress.c
   ${CMAKE_CURRENT_SOURCE_DIR}/src/lexaloffle/pxa_compress_snippets.c)
 

media/ascii_reference.png

@@ -0,0 +1,42 @@
+/** @file p8scii.c
+ *
+ *  A portable PICO-8 emulator written in C.
+ *
+ *  Copyright (c) 2025, Michael Fitzmayer. All rights reserved.
+ *  SPDX-License-Identifier: MIT
+ *
+ **/
+
+#include <stdint.h>
+#include "memory.h"
+#include "p8scii.h"
+
+#define FONT_WIDTH 3
+#define FONT_HEIGHT 5
+
+const uint8_t font[256][FONT_HEIGHT] =
+{
+    { 0b111, 0b101, 0b101, 0b101, 0b111 }
+};
+
+void blit_char_to_screen(uint8_t char_index, int x, int y, uint8_t color)
+{
+    const uint8_t* char_bitmap = font[char_index];
+
+    for (int row = 0; row < FONT_HEIGHT; row++)
+    {
+        uint8_t row_data = char_bitmap[row];
+        for (int col = 0; col < FONT_WIDTH; col++)
+        {
+            if (row_data & (1 << (FONT_WIDTH - 1 - col)))
+            {
+                int screen_x = x + col;
+                int screen_y = y + row;
+                uint16_t addr = 0x6000 + (screen_y << 6) + (screen_x >> 1);
+                uint8_t mask = (screen_x & 1) ? 0x0F : 0xF0;
+                uint8_t shift = (screen_x & 1) ? 4 : 0;
+                pico8_ram[addr] = (pico8_ram[addr] & mask) | (color << shift);
+            }
+        }
+    }
+}

src/p8scii.c

@@ -0,0 +1,17 @@
+/** @file p8scii.h
+ *
+ *  A portable PICO-8 emulator written in C.
+ *
+ *  Copyright (c) 2025, Michael Fitzmayer. All rights reserved.
+ *  SPDX-License-Identifier: MIT
+ *
+ **/
+
+#ifndef P8SCII_H
+#define P8SCII_H
+
+#include <stdint.h>
+
+void blit_char_to_screen(uint8_t char_index, int x, int y, uint8_t color);
+
+#endif // P8SCII_H