gr-sim: add SDL GR simulator

gr-sim/Makefile

@@ -0,0 +1,19 @@
+CC = gcc
+CFLAGS = -Wall -O2
+LFLAGS =
+
+SDL_LIBS= `sdl-config --libs`
+SDL_INCLUDE= `sdl-config --cflags`
+
+all:	gr-sim
+
+gr-sim:	gr-sim.o
+	$(CC) $(LFLAGS) $(SDL_LIBS) -o gr-sim gr-sim.o
+
+gr-sim.o:	gr-sim.c
+	$(CC) $(CFLAGS) $(SDL_INCLUDE) -c gr-sim.c
+
+clean:	
+	rm -f *~ *.o gr-sim
+
+

gr-sim/README

@@ -0,0 +1,4 @@
+Apple II low-res graphics simulator in SDL
+
+Useful to prototype games, etc., before committing to 6502 assembly.
+

gr-sim/gr-sim.c

@@ -0,0 +1,144 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <SDL.h>
+
+#define XSIZE		40
+#define YSIZE		48
+
+#define PIXEL_X_SCALE	14
+#define PIXEL_Y_SCALE	8
+
+static int xsize=XSIZE*PIXEL_X_SCALE;
+static int ysize=YSIZE*PIXEL_Y_SCALE;
+
+static unsigned char framebuffer[XSIZE][YSIZE];
+
+static int get_input(void) {
+
+	SDL_Event event;
+	int keypressed;
+
+
+	while ( SDL_PollEvent(&event)) {
+
+		switch(event.type) {
+
+		case SDL_KEYDOWN:
+			keypressed=event.key.keysym.sym;
+			switch (keypressed) {
+
+			case SDLK_ESCAPE:
+				return 'q';
+			default:
+				return keypressed;
+			}
+			break;
+
+
+		case SDL_JOYBUTTONDOWN:
+		case SDL_JOYAXISMOTION:
+		default:
+			printf("Unknown input action!\n");
+			break;
+
+		}
+	}
+
+	return 0;
+}
+
+
+
+
+static unsigned int color[16]={
+	0,		/*  0 black */
+	0xe31e60,	/*  1 magenta */
+	0x604ebd,	/*  2 dark blue */
+	0xff44fd,	/*  3 purple */
+	0x00a360,	/*  4 dark green */
+	0x9c9c9c,	/*  5 grey 1 */
+	0x14cffd,	/*  6 medium blue */
+	0xd0c3ff,	/*  7 light blue */
+	0x607203,	/*  8 brown */
+	0xff6a3c,	/*  9 orange */
+	0x9d9d9d,	/* 10 grey 2 */
+	0xffa0d0,	/* 11 pink */
+	0x14f53c,	/* 12 bright green */
+	0xd0dd8d,	/* 13 yellow */
+	0x72ffd0,	/* 14 aqua */
+	0xffffff,	/* 15 white */
+};
+
+static int gr_to_screen(SDL_Surface *screen) {
+
+	int x,y,i,j;
+	unsigned int *t_pointer;
+
+	t_pointer=((Uint32 *)screen->pixels);
+
+	for(y=0;y<YSIZE;y++) {
+		for(j=0;j<PIXEL_Y_SCALE;j++) {
+		for(x=0;x<XSIZE;x++) {
+			for(i=0;i<PIXEL_X_SCALE;i++) {
+				*t_pointer=color[framebuffer[x][y]];
+				t_pointer++;
+			}
+		}
+		}
+	}
+
+	SDL_UpdateRect(screen, 0, 0, xsize, ysize);
+
+	return 0;
+}
+
+
+int main(int argc, char **argv) {
+
+	SDL_Surface *sdl_screen=NULL;
+
+	int mode;
+	int ch;
+
+	int x,y;
+
+	mode=SDL_SWSURFACE|SDL_HWPALETTE|SDL_HWSURFACE;
+
+	if ( SDL_Init(SDL_INIT_VIDEO) < 0 ) {
+		fprintf(stderr,
+			"Couldn't initialize SDL: %s\n", SDL_GetError());
+		return -1;
+	}
+
+	/* Clean up on exit */
+	atexit(SDL_Quit);
+
+	/* assume 32-bit color */
+	sdl_screen = SDL_SetVideoMode(xsize, ysize, 32, mode);
+
+	if ( sdl_screen == NULL ) {
+		fprintf(stderr, "ERROR!  Couldn't set %dx%d video mode: %s\n",
+			xsize,ysize,SDL_GetError());
+		return -1;
+	}
+
+	/* Init screen */
+	for(y=0;y<YSIZE;y++) for(x=0;x<XSIZE;x++) framebuffer[x][y]=0;
+
+	/* Put rainbow on screen */
+	for(y=0;y<40;y++) for(x=0;x<XSIZE;x++) framebuffer[x][y]=y%16;
+
+	while(1) {
+		gr_to_screen(sdl_screen);
+
+		ch=get_input();
+		if (ch=='q') break;
+
+		usleep(100000);
+
+	}
+
+	return 0;
+}