Add implementation for bitmapwrite

src/debug/Makefile.am

@@ -24,6 +24,7 @@ libpspdebuginclude_HEADERS =	\
 lib_LIBRARIES = libpspdebug.a libpspgdb.a libpspgdb_user.a libpspgdb_kernel.a libpspdebugkb.a
 
 libpspdebug_a_SOURCES =		\
+	bitmap.c \
 	callstack.c		\
 	callstackget.S		\
 	font.c			\

src/debug/bitmap.c

@@ -0,0 +1,201 @@
+/*
+ * PSP Software Development Kit - https://github.com/pspdev
+ * -----------------------------------------------------------------------
+ * Licensed under the BSD license, see LICENSE in PSPSDK root for details.
+ *
+ *  bitmap.c - Take a screenshot and save it as a bitmap file
+ *
+ * Copyright (c) 2025, Francisco Javier Trujillo Mata <fjtrujy@gmail.com>
+ *
+ */
+
+#include <pspkernel.h>
+#include <pspdisplay.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+
+#define BMP_ID "BM"
+#define PSP_SCREEN_WIDTH 480
+#define PSP_SCREEN_HEIGHT 272
+#define PSP_LINE_SIZE 512
+#define BMP_RGB_BYTES_PER_PIXEL 3 // BMP format uses 24-bit RGB (3 bytes per pixel)
+
+// Helper function to get pixel depth in bytes for a given format
+static int get_pixel_depth(int format)
+{
+	switch (format)
+	{
+	case PSP_DISPLAY_PIXEL_FORMAT_565:
+	case PSP_DISPLAY_PIXEL_FORMAT_5551:
+	case PSP_DISPLAY_PIXEL_FORMAT_4444:
+		return 2; // 16-bit formats
+	case PSP_DISPLAY_PIXEL_FORMAT_8888:
+		return 4; // 32-bit format
+	default:
+		return 0; // Invalid format
+	}
+}
+
+struct BitmapHeader
+{
+	char id[2];
+	uint32_t filesize;
+	uint32_t reserved;
+	uint32_t offset;
+	uint32_t headsize;
+	uint32_t width;
+	uint32_t height;
+	uint16_t planes;
+	uint16_t bpp;
+	uint32_t comp;
+	uint32_t bitmapsize;
+	uint32_t hres;
+	uint32_t vres;
+	uint32_t colors;
+	uint32_t impcolors;
+} __attribute__((packed));
+
+static int fixed_write(int fd, void *data, int len)
+{
+	int writelen = 0;
+
+	while (writelen < len)
+	{
+		int ret;
+
+		ret = sceIoWrite(fd, data + writelen, len - writelen);
+		if (ret <= 0)
+		{
+			writelen = -1;
+			break;
+		}
+		writelen += ret;
+	}
+
+	return writelen;
+}
+
+void write_8888_line(void *frame, void *line_buf, int line)
+{
+	uint8_t *line_data = line_buf;
+	const int pixel_depth = get_pixel_depth(PSP_DISPLAY_PIXEL_FORMAT_8888);
+	uint8_t *p = frame + (line * PSP_LINE_SIZE * pixel_depth);
+	int i;
+
+	for (i = 0; i < PSP_SCREEN_WIDTH; i++)
+	{
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 2] = p[i * pixel_depth];
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 1] = p[(i * pixel_depth) + 1];
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 0] = p[(i * pixel_depth) + 2];
+	}
+}
+
+void write_5551_line(void *frame, void *line_buf, int line)
+{
+	uint8_t *line_data = line_buf;
+	const int pixel_depth = get_pixel_depth(PSP_DISPLAY_PIXEL_FORMAT_5551);
+	uint16_t *p = frame + (line * PSP_LINE_SIZE * pixel_depth);
+	int i;
+
+	for (i = 0; i < PSP_SCREEN_WIDTH; i++)
+	{
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 2] = (p[i] & 0x1F) << 3;
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 1] = ((p[i] >> 5) & 0x1F) << 3;
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 0] = ((p[i] >> 10) & 0x1F) << 3;
+	}
+}
+
+void write_565_line(void *frame, void *line_buf, int line)
+{
+	uint8_t *line_data = line_buf;
+	const int pixel_depth = get_pixel_depth(PSP_DISPLAY_PIXEL_FORMAT_565);
+	uint16_t *p = frame + (line * PSP_LINE_SIZE * pixel_depth);
+	int i;
+
+	for (i = 0; i < PSP_SCREEN_WIDTH; i++)
+	{
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 2] = (p[i] & 0x1F) << 3;
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 1] = ((p[i] >> 5) & 0x3F) << 2;
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 0] = ((p[i] >> 11) & 0x1F) << 3;
+	}
+}
+
+void write_4444_line(void *frame, void *line_buf, int line)
+{
+	uint8_t *line_data = line_buf;
+	const int pixel_depth = get_pixel_depth(PSP_DISPLAY_PIXEL_FORMAT_4444);
+	uint16_t *p = frame + (line * PSP_LINE_SIZE * pixel_depth);
+	int i;
+
+	for (i = 0; i < PSP_SCREEN_WIDTH; i++)
+	{
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 2] = (p[i] & 0xF) << 4;
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 1] = ((p[i] >> 4) & 0xF) << 4;
+		line_data[(i * BMP_RGB_BYTES_PER_PIXEL) + 0] = ((p[i] >> 8) & 0xF) << 4;
+	}
+}
+
+int bitmapWrite(void *frame_addr, int format, const char *file)
+{
+	struct BitmapHeader bmp;
+	uint8_t line_buf[PSP_SCREEN_WIDTH * BMP_RGB_BYTES_PER_PIXEL]; // Stack buffer for one line of RGB data
+	int fd;
+	int line;
+
+	// Initialize header
+	memset(&bmp, 0, sizeof(struct BitmapHeader));
+	memcpy(bmp.id, BMP_ID, sizeof(bmp.id));
+	bmp.filesize = PSP_SCREEN_WIDTH * PSP_SCREEN_HEIGHT * BMP_RGB_BYTES_PER_PIXEL + sizeof(struct BitmapHeader);
+	bmp.offset = sizeof(struct BitmapHeader);
+	bmp.headsize = 0x28;
+	bmp.width = PSP_SCREEN_WIDTH;
+	bmp.height = PSP_SCREEN_HEIGHT;
+	bmp.planes = 1;
+	bmp.bpp = BMP_RGB_BYTES_PER_PIXEL * 8; // Convert bytes to bits
+	bmp.bitmapsize = PSP_SCREEN_WIDTH * PSP_SCREEN_HEIGHT * BMP_RGB_BYTES_PER_PIXEL;
+	bmp.hres = 2834;
+	bmp.vres = 2834;
+
+	fd = sceIoOpen(file, PSP_O_WRONLY | PSP_O_CREAT | PSP_O_TRUNC, 0777);
+	if (fd < 0)
+	{
+		return -1;
+	}
+
+	// Write header first
+	if (fixed_write(fd, &bmp, sizeof(struct BitmapHeader)) != sizeof(struct BitmapHeader))
+	{
+		sceIoClose(fd);
+		return -1;
+	}
+
+	// Process and write each line (from bottom to top as required by BMP format)
+	for (line = PSP_SCREEN_HEIGHT - 1; line >= 0; line--)
+	{
+		switch (format)
+		{
+		case PSP_DISPLAY_PIXEL_FORMAT_565:
+			write_565_line(frame_addr, line_buf, line);
+			break;
+		case PSP_DISPLAY_PIXEL_FORMAT_5551:
+			write_5551_line(frame_addr, line_buf, line);
+			break;
+		case PSP_DISPLAY_PIXEL_FORMAT_4444:
+			write_4444_line(frame_addr, line_buf, line);
+			break;
+		case PSP_DISPLAY_PIXEL_FORMAT_8888:
+			write_8888_line(frame_addr, line_buf, line);
+			break;
+		}
+
+		if (fixed_write(fd, line_buf, sizeof(line_buf)) != sizeof(line_buf))
+		{
+			sceIoClose(fd);
+			return -1;
+		}
+	}
+
+	sceIoClose(fd);
+	return 0;
+}

src/debug/screenshot.c

@@ -10,8 +10,23 @@
  */
 
 #include "pspdebug.h"
+#include "pspdisplay.h"
+#include "pspuser.h"
+
+#define PSP_SCREEN_HEIGHT 272
+
+int bitmapWrite(void *frame_addr, int format, const char *file);
 
 int pspScreenshotSave(const char *filename)
 {
-    return 0;
+    void* buff;
+	int bufferwidth, pixelformat;
+
+    int ret = sceDisplayGetFrameBuf(&buff, &bufferwidth, &pixelformat, PSP_DISPLAY_SETBUF_NEXTHSYNC); 
+    if (ret != 0 || buff == NULL || bufferwidth == 0) {
+        return -1;
+    }
+    
+    // write the screenshot to the file
+    return bitmapWrite(buff, pixelformat, filename);
 }