Add support for borders, thanks Steward.

bittboy/Makefile

@@ -8,14 +8,14 @@
 CC        = /opt/bittboy-toolchain/usr/bin/arm-miyoo-linux-musleabi-gcc
 
 OBJS      = main.o cpu.o memory.o video.o input.o sound.o gui.o \
-            cheats.o zip.o  arm_stub.o  warm.o cpu_threaded.o video_blend.o sha1.o
+            cheats.o zip.o arm_stub.o  warm.o cpu_threaded.o video_blend.o sha1.o imageio.o
 
 BIN       = gpsp
 
 # Platform specific definitions 
 
 VPATH      += .. ../arm
-CFLAGS     += -DARM_ARCH -DPC_BUILD -Wall
+CFLAGS     += -DARM_ARCH -DPC_BUILD -DBITTBOY -Wall
 CFLAGS     += -Ofast -fdata-sections -ffunction-sections -flto -fno-PIC -fprofile-use
 CFLAGS     += `/opt/bittboy-toolchain/arm-miyoo-linux-musleabi/sysroot/usr/bin/sdl-config --cflags`
 

imageio.c

@@ -0,0 +1,127 @@
+// Written by Maarten ter Huurne in 2011.
+// Based on the libpng example.c source, with some additional inspiration
+// from SDL_image and openMSX.
+// License: GPL version 2 or later.
+#include <SDL.h>
+#include <png.h>
+#include <assert.h>
+
+SDL_Surface *loadPNG(const char* Path, uint32_t MaxWidth, uint32_t MaxHeight) {
+	// Declare these with function scope and initialize them to NULL,
+	// so we can use a single cleanup block at the end of the function.
+	SDL_Surface *surface = NULL;
+	FILE *fp = NULL;
+	png_structp png = NULL;
+	png_infop info = NULL;
+	png_bytep* rowPointers = NULL;
+
+	// Create and initialize the top-level libpng struct.
+	png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if (!png) goto cleanup;
+	// Create and initialize the image information struct.
+	info = png_create_info_struct(png);
+	if (!info) goto cleanup;
+	// Setup error handling for errors detected by libpng.
+	if (setjmp(png_jmpbuf(png))) {
+		// Note: This gets executed when an error occurs.
+		if (surface) {
+			SDL_FreeSurface(surface);
+			surface = NULL;
+		}
+		goto cleanup;
+	}
+
+	fp = fopen(Path, "rb");
+	if (!fp) goto cleanup;
+
+	// Set up the input control if you are using standard C streams.
+	png_init_io(png, fp);
+
+	// The call to png_read_info() gives us all of the information from the
+	// PNG file before the first IDAT (image data chunk).
+	png_read_info(png, info);
+	png_uint_32 width, height;
+	int bitDepth, colorType;
+	png_get_IHDR(
+		png, info, &width, &height, &bitDepth, &colorType, NULL, NULL, NULL);
+
+	// Select ARGB pixel format:
+	// (ARGB is the native pixel format for the JZ47xx frame buffer in 24bpp)
+	// - strip 16 bit/color files down to 8 bits/color
+	png_set_strip_16(png);
+	// - convert 1/2/4 bpp to 8 bpp
+	png_set_packing(png);
+	// - expand paletted images to RGB
+	// - expand grayscale images of less than 8-bit depth to 8-bit depth
+	// - expand tRNS chunks to alpha channels
+	png_set_expand(png);
+	// - convert grayscale to RGB
+	png_set_gray_to_rgb(png);
+	// - add alpha channel
+	png_set_add_alpha(png, 0xFF, PNG_FILLER_AFTER);
+	// - convert RGBA to ARGB
+	if (SDL_BYTEORDER == SDL_BIG_ENDIAN) {
+		png_set_swap_alpha(png);
+	} else {
+		png_set_bgr(png); // BGRA in memory becomes ARGB in register
+	}
+
+	// Update the image info to the post-conversion state.
+	png_read_update_info(png, info);
+	png_get_IHDR(
+		png, info, &width, &height, &bitDepth, &colorType, NULL, NULL, NULL);
+	assert(bitDepth == 8);
+	assert(colorType == PNG_COLOR_TYPE_RGB_ALPHA);
+
+	// Refuse to load outrageously large images.
+	if (width > MaxWidth) {
+		goto cleanup;
+	}
+	if (height > MaxHeight) {
+		goto cleanup;
+	}
+
+	// Allocate ARGB surface to hold the image.
+	surface = SDL_CreateRGBSurface(
+		SDL_SWSURFACE | SDL_SRCALPHA, width, height, 32,
+		0x00FF0000, 0x0000FF00, 0x000000FF, 0xFF000000
+		);
+	if (!surface) {
+		// Failed to create surface, probably out of memory.
+		goto cleanup;
+	}
+
+	// Compute row pointers.
+	rowPointers = malloc(height * sizeof(png_bytep));
+	if (!rowPointers) {
+		// Probably out of memory.
+		if (surface) {
+			SDL_FreeSurface(surface);
+			surface = NULL;
+		}
+		goto cleanup;
+	}
+	png_uint_32 y;
+	for (y = 0; y < height; y++) {
+		rowPointers[y] =
+			(png_bytep) (surface->pixels) + y * surface->pitch;
+	}
+
+	// Read the entire image in one go.
+	png_read_image(png, rowPointers);
+
+	// Read rest of file, and get additional chunks in the info struct.
+	// Note: We got all we need, so skip this step.
+	//png_read_end(png, info);
+
+cleanup:
+	// Clean up.
+	if (rowPointers) {
+		free(rowPointers);
+		rowPointers = NULL;
+	}
+	png_destroy_read_struct(&png, &info, NULL);
+	if (fp) fclose(fp);
+
+	return surface;
+}// Written by Maarten ter Huurne in 2011.