Add screenshot capability

CMakeLists.txt

@@ -85,7 +85,7 @@ endif()
 source_group("ARM debugger" FILES ${DEBUGGER_SRC})
 
 add_library(${BINARY_NAME} SHARED ${ARM_SRC} ${GBA_SRC} ${DEBUGGER_SRC} ${RENDERER_SRC} ${UTIL_SRC} ${VFS_SRC} ${OS_SRC})
-target_link_libraries(${BINARY_NAME} m ${DEBUGGER_LIB} ${OS_LIB} ${DEPENDENCY_LIB})
+target_link_libraries(${BINARY_NAME} m ${DEBUGGER_LIB} ${OS_LIB} ${DEPENDENCY_LIB} png)
 
 if(BUILD_SDL)
 	add_subdirectory(${CMAKE_SOURCE_DIR}/src/platform/sdl ${CMAKE_BINARY_DIR}/sdl)

src/platform/sdl/gl-main.c

@@ -77,6 +77,7 @@ int main(int argc, char** argv) {
 	renderer.events.fullscreen = graphicsOpts.fullscreen;
 	renderer.events.windowUpdated = 0;
 #endif
+	renderer.events.renderer = &renderer.d;
 
 	if (!_GBASDLInit(&renderer)) {
 		freeOptions(&opts);

src/platform/sdl/sdl-events.c

@@ -5,6 +5,9 @@
 #include "gba-rr.h"
 #include "gba-serialize.h"
 #include "gba-video.h"
+#include "renderers/video-software.h"
+#include "util/png-io.h"
+#include "util/vfs.h"
 
 #if SDL_VERSION_ATLEAST(2, 0, 0) && defined(__APPLE__)
 #define GUI_MOD KMOD_GUI
@@ -15,6 +18,8 @@
 #define SDL_BINDING_KEY 0x53444C4B
 #define SDL_BINDING_BUTTON 0x53444C42
 
+static void _takeScreenshot(struct GBAThread*, struct GBASDLEvents*);
+
 bool GBASDLInitEvents(struct GBASDLEvents* context) {
 	if (SDL_InitSubSystem(SDL_INIT_JOYSTICK) < 0) {
 		return false;
@@ -74,6 +79,13 @@ static void _GBASDLHandleKeypress(struct GBAThread* context, struct GBASDLEvents
 			ARMDebuggerEnter(context->debugger, DEBUGGER_ENTER_MANUAL);
 		}
 		return;
+	case SDLK_F12:
+		if (event->type == SDL_KEYDOWN) {
+			GBAThreadInterrupt(context);
+			_takeScreenshot(context, sdlContext);
+			GBAThreadContinue(context);
+		}
+		return;
 	case SDLK_TAB:
 		context->sync.audioWait = event->type != SDL_KEYDOWN;
 		return;
@@ -249,3 +261,12 @@ void GBASDLHandleEvent(struct GBAThread* context, struct GBASDLEvents* sdlContex
 		_GBASDLHandleJoyHat(context, &event->jhat);
 	}
 }
+
+static void _takeScreenshot(struct GBAThread* context, struct GBASDLEvents* sdlContext) {
+	struct VFile* vf = context->stateDir->openFile(context->stateDir, "screenshot.png", O_CREAT | O_WRONLY);
+	png_structp png = PNGWriteOpen(vf);
+	png_infop info = PNGWriteHeader(png, VIDEO_HORIZONTAL_PIXELS, VIDEO_VERTICAL_PIXELS);
+	PNGWritePixels(png, VIDEO_HORIZONTAL_PIXELS, VIDEO_VERTICAL_PIXELS, 256, sdlContext->renderer->outputBuffer);
+	PNGWriteClose(png, info);
+	vf->close(vf);
+}

src/platform/sdl/sdl-events.h

@@ -7,8 +7,11 @@
 
 #include <SDL.h>
 
+struct GBAVideoSoftwareRenderer;
+
 struct GBASDLEvents {
 	struct GBAInputMap* bindings;
+	struct GBAVideoSoftwareRenderer* renderer;
 	SDL_Joystick* joystick;
 #if SDL_VERSION_ATLEAST(2, 0, 0)
 	SDL_Window* window;

src/util/png-io.c

@@ -0,0 +1,76 @@
+#include "util/png-io.h"
+
+#include "vfs.h"
+
+static void _pngWrite(png_structp png, png_bytep buffer, png_size_t size) {
+	struct VFile* vf = png_get_io_ptr(png);
+	size_t written = vf->write(vf, buffer, size);
+	if (written != size) {
+		png_error(png, "Could not write PNG");
+	}
+}
+
+png_structp PNGWriteOpen(struct VFile* source) {
+	png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0, 0);
+	if (!png) {
+		return 0;
+	}
+	if (setjmp(png_jmpbuf(png))) {
+		png_destroy_write_struct(&png, 0);
+		return 0;
+	}
+	png_set_write_fn(png, source, _pngWrite, 0);
+	return png;
+}
+
+png_infop PNGWriteHeader(png_structp png, unsigned width, unsigned height) {
+	png_infop info = png_create_info_struct(png);
+	if (!info) {
+		return 0;
+	}
+	png_set_IHDR(png, info, width, height, 8, PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
+	png_write_info(png, info);
+	return info;
+}
+
+bool PNGWritePixels(png_structp png, unsigned width, unsigned height, unsigned stride, void* pixels) {
+	png_bytep row = malloc(sizeof(png_bytep) * width * 3);
+	if (!row) {
+		return false;
+	}
+	png_bytep pixelData = pixels;
+	if (setjmp(png_jmpbuf(png))) {
+		free(row);
+		return false;
+	}
+	unsigned i;
+	for (i = 0; i < height; ++i) {
+		unsigned x;
+		for (x = 0; x < width; ++x) {
+			row[x * 3] = pixelData[stride * i * 4 + x * 4];
+			row[x * 3 + 1] = pixelData[stride * i * 4 + x * 4 + 1];
+			row[x * 3 + 2] = pixelData[stride * i * 4 + x * 4 + 2];
+		}
+		png_write_row(png, row);
+	}
+	free(row);
+	return true;
+}
+
+bool PNGWriteCustomChunk(png_structp png, const char* name, size_t size, void* data) {
+	char realName[5];
+	strncpy(realName, name, 4);
+	realName[0] = tolower(realName[0]);
+	realName[1] = tolower(realName[1]);
+	realName[4] = '\0';
+	if (setjmp(png_jmpbuf(png))) {
+		return false;
+	}
+	png_write_chunk(png, (png_const_bytep) realName, data, size);
+	return true;
+}
+
+void PNGWriteClose(png_structp png, png_infop info) {
+	png_write_end(png, info);
+	png_destroy_write_struct(&png, &info);
+}

src/util/png-io.h

@@ -0,0 +1,16 @@
+#ifndef PNG_IO_H
+#define PNG_IO_H
+
+#include "common.h"
+
+#include <png.h>
+
+struct VFile;
+
+png_structp PNGWriteOpen(struct VFile* source);
+png_infop PNGWriteHeader(png_structp png, unsigned width, unsigned height);
+bool PNGWritePixels(png_structp png, unsigned width, unsigned height, unsigned stride, void* pixels);
+bool PNGWriteCustomChunk(png_structp png, const char* name, size_t size, void* data);
+void PNGWriteClose(png_structp png, png_infop info);
+
+#endif