changeset 449:7696d824489d opengl

Started work on OpenGL support in new branch
author Mike Pavone <pavone@retrodev.com>
date Tue, 23 Jul 2013 23:01:03 -0700
parents 006008a3f370
children c08a4efeee7f
files blastem.c render.h render_sdl.c
diffstat 3 files changed, 242 insertions(+), 147 deletions(-) [+]
line wrap: on
line diff
--- a/blastem.c	Sun Jul 07 15:05:50 2013 -0700
+++ b/blastem.c	Tue Jul 23 23:01:03 2013 -0700
@@ -50,7 +50,7 @@
 	uint8_t block[SMD_BLOCK_SIZE];
 	filesize -= SMD_HEADER_SIZE;
 	fseek(f, SMD_HEADER_SIZE, SEEK_SET);
-	
+
 	uint16_t * dst = cart;
 	while (filesize > 0) {
 		fread(block, 1, SMD_BLOCK_SIZE, f);
@@ -137,15 +137,15 @@
 				if (next_hint < context->int_cycle) {
 					context->int_cycle = next_hint;
 					context->int_num = 4;
-			
+
 				}
 			}
 		}
 	}
 
 	context->target_cycle = context->int_cycle < context->sync_cycle ? context->int_cycle : context->sync_cycle;
-	/*printf("Cyc: %d, Trgt: %d, Int Cyc: %d, Int: %d, Mask: %X, V: %d, H: %d, HICount: %d, HReg: %d, Line: %d\n", 
-		context->current_cycle, context->target_cycle, context->int_cycle, context->int_num, (context->status & 0x7), 
+	/*printf("Cyc: %d, Trgt: %d, Int Cyc: %d, Int: %d, Mask: %X, V: %d, H: %d, HICount: %d, HReg: %d, Line: %d\n",
+		context->current_cycle, context->target_cycle, context->int_cycle, context->int_num, (context->status & 0x7),
 		v_context->regs[REG_MODE_2] & 0x20, v_context->regs[REG_MODE_1] & 0x10, v_context->hint_counter, v_context->regs[REG_HINT], v_context->cycles / MCLKS_LINE);*/
 }
 
@@ -197,7 +197,7 @@
 	//printf("YM | Cycle: %d, bpos: %d, PSG | Cycle: %d, bpos: %d\n", gen->ym->current_cycle, gen->ym->buffer_pos, gen->psg->cycles, gen->psg->buffer_pos * 2);
 	psg_run(gen->psg, target);
 	ym_run(gen->ym, target);
-	
+
 	//printf("Target: %d, YM bufferpos: %d, PSG bufferpos: %d\n", target, gen->ym->buffer_pos, gen->psg->buffer_pos * 2);
 }
 
@@ -219,7 +219,7 @@
 		}
 		//printf("reached frame end | 68K Cycles: %d, MCLK Cycles: %d\n", context->current_cycle, mclks);
 		vdp_run_context(v_context, mclks_per_frame);
-		
+
 		if (!headless) {
 			break_on_sync |= wait_render_frame(v_context, frame_limit);
 		}
@@ -496,7 +496,7 @@
 				}
 				if (value & 1) {
 					dputs("bus requesting Z80");
-					
+
 					if(!reset && !busreq) {
 						busack_cycle = ((gen->z80->current_cycle + Z80_ACK_DELAY) * MCLKS_PER_Z80) / MCLKS_PER_68K;//context->current_cycle + Z80_ACK_DELAY;
 						new_busack = Z80_REQ_ACK;
@@ -518,7 +518,7 @@
 					}
 					//busack_cycle = CYCLE_NEVER;
 					//busack = Z80_REQ_BUSY;
-					
+
 				}
 			} else if (location == 0x1200) {
 				sync_z80(gen->z80, context->current_cycle * MCLKS_PER_68K);
@@ -1433,7 +1433,7 @@
 				//Z80 debug commands
 				switch(input_buf[1])
 				{
-				case 'b': 
+				case 'b':
 					param = find_param(input_buf);
 					if (!param) {
 						fputs("zb command requires a parameter\n", stderr);
@@ -1552,7 +1552,7 @@
 	context->flags[ZF_Z] = f & 1;
 	f >>= 1;
 	context->flags[ZF_S] = f;
-	
+
 	context->regs[Z80_A] = *curpos;
 	curpos += 3;
 	for (int reg = Z80_C; reg <= Z80_IYH; reg++) {
@@ -1640,7 +1640,7 @@
 	adjust_int_cycle(gen->m68k, gen->vdp);
 	fclose(gstfile);
 	return pc;
-	
+
 error_close:
 	fclose(gstfile);
 error:
@@ -1658,7 +1658,7 @@
 const memmap_chunk static_map[] = {
 		{0,        0x400000,  0xFFFFFF, 0, MMAP_READ,                          cart,
 		           NULL,          NULL,         NULL,            NULL},
-		{0xE00000, 0x1000000, 0xFFFF,   0, MMAP_READ | MMAP_WRITE | MMAP_CODE, ram, 
+		{0xE00000, 0x1000000, 0xFFFF,   0, MMAP_READ | MMAP_WRITE | MMAP_CODE, ram,
 		           NULL,          NULL,         NULL,            NULL},
 		{0xC00000, 0xE00000,  0x1FFFFF, 0, 0,                                  NULL,
 		           (read_16_fun)vdp_port_read,  (write_16_fun)vdp_port_write,
@@ -1711,7 +1711,7 @@
 			memmap[0].mask = 0xFFFFFF;
 			memmap[0].flags = MMAP_READ;
 			memmap[0].buffer = cart;
-			
+
 			ram_start &= 0xFFFFFE;
 			ram_end |= 1;
 			memmap[1].start = ram_start;
@@ -1728,7 +1728,7 @@
 				size /= 2;
 			}
 			memmap[1].buffer = gen->save_ram = malloc(size);
-			
+
 			memcpy(memmap+2, static_map+1, sizeof(static_map)-sizeof(static_map[0]));
 			num_chunks = sizeof(static_map)/sizeof(memmap_chunk)+1;
 		} else {
@@ -1737,7 +1737,7 @@
 			memmap[0].mask = 0xFFFFFF;
 			memmap[0].flags = MMAP_READ;
 			memmap[0].buffer = cart;
-			
+
 			memmap[1].start = 0x200000;
 			memmap[1].end = 0x400000;
 			memmap[1].mask = 0x1FFFFF;
@@ -1757,7 +1757,7 @@
 			memmap[num_chunks].end = 0xA13100;
 			memmap[num_chunks].mask = 0xFF;
 			memmap[num_chunks].write_16 = (write_16_fun)write_bank_reg_w;
-			memmap[num_chunks].write_8 = (write_8_fun)write_bank_reg_b; 
+			memmap[num_chunks].write_8 = (write_8_fun)write_bank_reg_b;
 			num_chunks++;
 			ram_end++;
 			size = ram_end-ram_start;
@@ -1786,7 +1786,7 @@
 	init_x86_68k_opts(&opts, memmap, num_chunks);
 	opts.address_log = address_log;
 	init_68k_context(&context, opts.native_code_map, &opts);
-	
+
 	context.video_context = gen->vdp;
 	context.system = gen;
 	//cartridge ROM
@@ -1958,18 +1958,18 @@
 		fps = 50;
 	}
 	if (!headless) {
-		render_init(width, height, title, fps);
+		render_init(width, height, title, fps, 0);
 	}
 	vdp_context v_context;
-	
+
 	init_vdp_context(&v_context);
-	
+
 	ym2612_context y_context;
 	ym_init(&y_context, render_sample_rate(), fps == 60 ? MCLKS_NTSC : MCLKS_PAL, MCLKS_PER_YM, render_audio_buffer(), ym_log ? YM_OPT_WAVE_LOG : 0);
-	
+
 	psg_context p_context;
 	psg_init(&p_context, render_sample_rate(), fps == 60 ? MCLKS_NTSC : MCLKS_PAL, MCLKS_PER_PSG, render_audio_buffer());
-	
+
 	z80_context z_context;
 	x86_z80_options z_opts;
 	init_x86_z80_opts(&z_opts);
@@ -1983,13 +1983,13 @@
 	z_context.sync_cycle = z_context.target_cycle = mclks_per_frame/MCLKS_PER_Z80;
 	z_context.int_cycle = CYCLE_NEVER;
 	z_context.mem_pointers[1] = z_context.mem_pointers[2] = (uint8_t *)cart;
-	
+
 	gen.z80 = &z_context;
 	gen.vdp = &v_context;
 	gen.ym = &y_context;
 	gen.psg = &p_context;
 	genesis = &gen;
-	
+
 	int fname_size = strlen(argv[1]);
 	sram_filename = malloc(fname_size+6);
 	memcpy(sram_filename, argv[1], fname_size);
@@ -2004,7 +2004,7 @@
 		strcpy(sram_filename + fname_size, ".sram");
 	}
 	set_keybindings();
-	
+
 	init_run_cpu(&gen, debug, address_log, statefile);
 	return 0;
 }
--- a/render.h	Sun Jul 07 15:05:50 2013 -0700
+++ b/render.h	Tue Jul 23 23:01:03 2013 -0700
@@ -4,9 +4,17 @@
 #include "vdp.h"
 #include "psg.h"
 #include "ym2612.h"
+
+typedef struct {
+	void *oddbuf;
+	void *evenbuf;
+	int  stride;
+} surface_info;
+
 uint32_t render_map_color(uint8_t r, uint8_t g, uint8_t b);
+surface_info render_alloc_surfaces();
 uint8_t render_depth();
-void render_init(int width, int height, char * title, uint32_t fps);
+void render_init(int width, int height, char * title, uint32_t fps, uint8_t use_gl);
 void render_context(vdp_context * context);
 void render_wait_quit(vdp_context * context);
 void render_wait_psg(psg_context * context);
--- a/render_sdl.c	Sun Jul 07 15:05:50 2013 -0700
+++ b/render_sdl.c	Tue Jul 23 23:01:03 2013 -0700
@@ -4,9 +4,14 @@
 #include "blastem.h"
 #include "io.h"
 
+#ifndef DISABLE_OPENGL
+#include <GL/gl.h>
+#endif
+
 SDL_Surface *screen;
 uint8_t render_dbg = 0;
 uint8_t debug_pal = 0;
+uint8_t render_gl;
 
 uint32_t last_frame = 0;
 
@@ -75,7 +80,54 @@
 
 uint32_t render_map_color(uint8_t r, uint8_t g, uint8_t b)
 {
-	return SDL_MapRGB(screen->format, r, g, b);
+	if (render_gl) {
+		return b << 24 | g << 16 | r << 8 | 255;
+	} else {
+		return SDL_MapRGB(screen->format, r, g, b);
+	}
+}
+
+GLuint textures[3], buffers[2];
+
+const GLfloat vertex_data[] = {
+	-1.0f, -1.0f,
+	 1.0f, -1.0f,
+	-1.0f,  1.0f,
+	 1.0f,  1.0f
+};
+
+const GLushort element_data[] = {0, 1, 2, 3};
+
+void render_alloc_surfaces(vdp_context * context)
+{
+	if (render_gl) {
+		context->oddbuf = context->framebuf = malloc(320 * 240 * 4 * 2);
+		memset(context->oddbuf, 0, 320 * 240 * 4 * 2);
+		context->evenbuf = ((char *)context->oddbuf) + 320 * 240 * 4;
+		glGenTextures(3, textures);
+		for (int i = 0; i < 3; i++)
+		{
+			glBindTexture(GL_TEXTURE_2D, textures[i]);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+			glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+			if (i < 2) {
+				glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8‚Äč, 512, 256, 0, GL_BGRA, GL_UNSIGNED_BYTE, i ? context->evenbuf : context->oddbuf);
+			} else {
+				uint32_t blank = 255;
+				glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 1, 1, 0, GL_BGRA, GL_UNSIGNED_BYTE, &blank);
+			}
+		}
+		glGenBuffers(2, buffers);
+		glBindBuffer(GL_ARRAY_BUFFER, buffers[0]);
+		glBufferData(GL_ARRAY_BUFFER, sizeof(vertex_data), vertex_data, GL_STATIC_DRAW);
+		glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffers[0]);
+		glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(element_data), element_data, GL_STATIC_DRAW);
+	} else {
+		context->oddbuf = context->framebuf = malloc(320 * 240 * screen->format->BytesPerPixel * 2);
+		context->evenbuf = ((char *)context->oddbuf) + 320 * 240 * screen->format->BytesPerPixel;
+	}
 }
 
 uint8_t render_depth()
@@ -83,74 +135,104 @@
 	return screen->format->BytesPerPixel * 8;
 }
 
-void render_init(int width, int height, char * title, uint32_t fps)
+void render_init(int width, int height, char * title, uint32_t fps, uint8_t use_gl)
 {
 	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO | SDL_INIT_JOYSTICK) < 0) {
-        fprintf(stderr, "Unable to init SDL: %s\n", SDL_GetError());
-        exit(1);
-    }
-    atexit(SDL_Quit);
-    atexit(render_close_audio);
-    printf("width: %d, height: %d\n", width, height);
-    screen = SDL_SetVideoMode(width, height, 32, SDL_SWSURFACE | SDL_ANYFORMAT);
-    if (!screen) {
-    	fprintf(stderr, "Unable to get SDL surface: %s\n", SDL_GetError());
-        exit(1);
-    }
-    if (screen->format->BytesPerPixel != 2 && screen->format->BytesPerPixel != 4) {
-    	fprintf(stderr, "BlastEm requires a 16-bit or 32-bit surface, SDL returned a %d-bit surface\n", screen->format->BytesPerPixel * 8);
-    	exit(1);
-    }
-    SDL_WM_SetCaption(title, title);
-    min_delay = 0;
-    for (int i = 0; i < 100; i++) {
-    	uint32_t start = SDL_GetTicks();
-    	SDL_Delay(1);
-    	uint32_t delay = SDL_GetTicks()-start;
-    	if (delay > min_delay) {
-    		min_delay = delay;
-    	}
-    }
-    if (!min_delay) {
-    	min_delay = 1;
-    }
-    printf("minimum delay: %d\n", min_delay);
-    
-    frame_delay = 1000/fps;
-    
-    audio_mutex = SDL_CreateMutex();
-    psg_cond = SDL_CreateCond();
-    ym_cond = SDL_CreateCond();
-    audio_ready = SDL_CreateCond();
-    
-    SDL_AudioSpec desired, actual;
-    desired.freq = 48000;
-    desired.format = AUDIO_S16SYS;
-    desired.channels = 2;
-    desired.samples = 2048;//1024;
-    desired.callback = audio_callback;
-    desired.userdata = NULL;
-    
-    if (SDL_OpenAudio(&desired, &actual) < 0) {
-    	fprintf(stderr, "Unable to open SDL audio: %s\n", SDL_GetError());
-    	exit(1);
-    }
-    buffer_samples = actual.samples;
-    sample_rate = actual.freq;
-    printf("Initialized audio at frequency %d with a %d sample buffer\n", actual.freq, actual.samples);
-    SDL_PauseAudio(0);
-    num_joysticks = SDL_NumJoysticks();
-    if (num_joysticks > MAX_JOYSTICKS) {
-    	num_joysticks = MAX_JOYSTICKS;
-    }
-    for (int i = 0; i < num_joysticks; i++) {
-    	printf("Joystick %d: %s\n", i, SDL_JoystickName(i));
-    	SDL_Joystick * joy = joysticks[i] = SDL_JoystickOpen(i);
-    	if (joy) {
-    		printf("\tNum Axes: %d\n\tNum Buttons: %d\n\tNum Hats: %d\n", SDL_JoystickNumAxes(joy), SDL_JoystickNumButtons(joy), SDL_JoystickNumHats(joy));
-    	}
-    }
-    SDL_JoystickEventState(SDL_ENABLE);
+		fprintf(stderr, "Unable to init SDL: %s\n", SDL_GetError());
+		exit(1);
+	}
+	atexit(SDL_Quit);
+	atexit(render_close_audio);
+	printf("width: %d, height: %d\n", width, height);
+	uint32_t flags
+#ifndef DISABLE_OPENGL
+	if (use_gl)
+	{
+		SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 5);
+		SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 5);
+		SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 5);
+		SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 0);
+		SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+		flags = SDL_OPENGL;
+	} else {
+#else
+	{
+#endif
+		flags = SDL_SWSURFACE | SDL_ANYFORMAT;
+	}
+	screen = SDL_SetVideoMode(width, height, 32, flags);
+	if (!screen) {
+		fprintf(stderr, "Unable to get SDL surface: %s\n", SDL_GetError());
+		exit(1);
+	}
+	if (!use_gl && screen->format->BytesPerPixel != 2 && screen->format->BytesPerPixel != 4) {
+		fprintf(stderr, "BlastEm requires a 16-bit or 32-bit surface, SDL returned a %d-bit surface\n", screen->format->BytesPerPixel * 8);
+		exit(1);
+	}
+#ifndef DISABLE_OPENGL
+	//TODO: Fallback to plain SDL if OpenGL 2.0 not available
+	render_gl = use_gl;
+#endif
+	SDL_WM_SetCaption(title, title);
+	min_delay = 0;
+	for (int i = 0; i < 100; i++) {
+		uint32_t start = SDL_GetTicks();
+		SDL_Delay(1);
+		uint32_t delay = SDL_GetTicks()-start;
+		if (delay > min_delay) {
+			min_delay = delay;
+		}
+	}
+	if (!min_delay) {
+		min_delay = 1;
+	}
+	printf("minimum delay: %d\n", min_delay);
+
+	frame_delay = 1000/fps;
+
+	audio_mutex = SDL_CreateMutex();
+	psg_cond = SDL_CreateCond();
+	ym_cond = SDL_CreateCond();
+	audio_ready = SDL_CreateCond();
+
+	SDL_AudioSpec desired, actual;
+	desired.freq = 48000;
+	desired.format = AUDIO_S16SYS;
+	desired.channels = 2;
+	desired.samples = 2048;//1024;
+	desired.callback = audio_callback;
+	desired.userdata = NULL;
+
+	if (SDL_OpenAudio(&desired, &actual) < 0) {
+		fprintf(stderr, "Unable to open SDL audio: %s\n", SDL_GetError());
+		exit(1);
+	}
+	buffer_samples = actual.samples;
+	sample_rate = actual.freq;
+	printf("Initialized audio at frequency %d with a %d sample buffer\n", actual.freq, actual.samples);
+	SDL_PauseAudio(0);
+	num_joysticks = SDL_NumJoysticks();
+	if (num_joysticks > MAX_JOYSTICKS) {
+		num_joysticks = MAX_JOYSTICKS;
+	}
+	for (int i = 0; i < num_joysticks; i++) {
+		printf("Joystick %d: %s\n", i, SDL_JoystickName(i));
+		SDL_Joystick * joy = joysticks[i] = SDL_JoystickOpen(i);
+		if (joy) {
+			printf("\tNum Axes: %d\n\tNum Buttons: %d\n\tNum Hats: %d\n", SDL_JoystickNumAxes(joy), SDL_JoystickNumButtons(joy), SDL_JoystickNumHats(joy));
+		}
+	}
+	SDL_JoystickEventState(SDL_ENABLE);
+}
+
+void render_context_gl(vdp_context * context)
+{
+	glBindTexture(GL_TEXTURE_2D, textures[context->framebuf == context->oddbuf ? 0 : 1]);
+	glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, 320, 240, GL_BGRA, GL_UNSIGNED_BYTE, context->framebuf);;
+
+	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
+	glClear(GL_COLOR_BUFFER_BIT);
+
 }
 
 uint32_t blankbuf[320*240];
@@ -158,64 +240,69 @@
 void render_context(vdp_context * context)
 {
 	uint16_t *buf_16;
-	uint32_t *buf_32; 
+	uint32_t *buf_32;
 	uint8_t b,g,r;
 	last_frame = SDL_GetTicks();
+	if (render_gl)
+	{
+		render_context_gl(context);
+		return;
+	}
 	if (SDL_MUSTLOCK(screen)) {
 		if (SDL_LockSurface(screen) < 0) {
 			return;
 		}
-    }
-    uint16_t repeat_x = screen->clip_rect.w / 320;
-    uint16_t repeat_y = screen->clip_rect.h / 240;
-    if (repeat_x > repeat_y) {
-    	repeat_x = repeat_y;
-    } else {
-    	repeat_y = repeat_x;
-    }
-    int othermask = repeat_y >> 1;
-    
-    if (screen->format->BytesPerPixel == 2) {
-    	uint16_t *otherbuf = (context->regs[REG_MODE_4] & BIT_INTERLACE) ? context->evenbuf : (uint16_t *)blankbuf;
-    	uint16_t * oddbuf = context->oddbuf;
-    	buf_16 = (uint16_t *)screen->pixels;
-    	for (int y = 0; y < 240; y++) {
-    		for (int i = 0; i < repeat_y; i++,buf_16 += screen->pitch/2) {
-        		uint16_t *line = buf_16;
-        		uint16_t *src_line = (i & othermask ? otherbuf : oddbuf) + y * 320;
-		    	for (int x = 0; x < 320; x++) {
-		    		uint16_t color = *(src_line++);
-		    		for (int j = 0; j < repeat_x; j++) {
-		    			*(line++) = color;
-		    		}
-		    	}
-		    }
-    	}
-    } else {
-    	uint32_t *otherbuf = (context->regs[REG_MODE_4] & BIT_INTERLACE) ? context->evenbuf : (uint32_t *)blankbuf;
-    	uint32_t * oddbuf = context->oddbuf;
-    	buf_32 = (uint32_t *)screen->pixels;
-    	for (int y = 0; y < 240; y++) {
-    		for (int i = 0; i < repeat_y; i++,buf_32 += screen->pitch/4) {
-        		uint32_t *line = buf_32;
-        		uint32_t *src_line = (i & othermask ? otherbuf : oddbuf) + y * 320;
-		    	for (int x = 0; x < 320; x++) {
-		    		uint32_t color = *(src_line++);
-		    		for (int j = 0; j < repeat_x; j++) {
-		    			*(line++) = color;
-		    		}
-		    	}
-		    }
-    	}
-    }
-    if ( SDL_MUSTLOCK(screen) ) {
-        SDL_UnlockSurface(screen);
-    }
-    SDL_UpdateRect(screen, 0, 0, screen->clip_rect.w, screen->clip_rect.h);
-    if (context->regs[REG_MODE_4] & BIT_INTERLACE)
-    {
-    	context->framebuf = context->framebuf == context->oddbuf ? context->evenbuf : context->oddbuf;
-    }
+	}
+	uint16_t repeat_x = screen->clip_rect.w / 320;
+	uint16_t repeat_y = screen->clip_rect.h / 240;
+	if (repeat_x > repeat_y) {
+		repeat_x = repeat_y;
+	} else {
+		repeat_y = repeat_x;
+	}
+	int othermask = repeat_y >> 1;
+
+	if (screen->format->BytesPerPixel == 2) {
+		uint16_t *otherbuf = (context->regs[REG_MODE_4] & BIT_INTERLACE) ? context->evenbuf : (uint16_t *)blankbuf;
+		uint16_t * oddbuf = context->oddbuf;
+		buf_16 = (uint16_t *)screen->pixels;
+		for (int y = 0; y < 240; y++) {
+			for (int i = 0; i < repeat_y; i++,buf_16 += screen->pitch/2) {
+				uint16_t *line = buf_16;
+				uint16_t *src_line = (i & othermask ? otherbuf : oddbuf) + y * 320;
+				for (int x = 0; x < 320; x++) {
+					uint16_t color = *(src_line++);
+					for (int j = 0; j < repeat_x; j++) {
+						*(line++) = color;
+					}
+				}
+			}
+		}
+	} else {
+		uint32_t *otherbuf = (context->regs[REG_MODE_4] & BIT_INTERLACE) ? context->evenbuf : (uint32_t *)blankbuf;
+		uint32_t * oddbuf = context->oddbuf;
+		buf_32 = (uint32_t *)screen->pixels;
+		for (int y = 0; y < 240; y++) {
+			for (int i = 0; i < repeat_y; i++,buf_32 += screen->pitch/4) {
+				uint32_t *line = buf_32;
+				uint32_t *src_line = (i & othermask ? otherbuf : oddbuf) + y * 320;
+				for (int x = 0; x < 320; x++) {
+					uint32_t color = *(src_line++);
+					for (int j = 0; j < repeat_x; j++) {
+						*(line++) = color;
+					}
+				}
+			}
+		}
+	}
+	if ( SDL_MUSTLOCK(screen) ) {
+		SDL_UnlockSurface(screen);
+	}
+	SDL_UpdateRect(screen, 0, 0, screen->clip_rect.w, screen->clip_rect.h);
+	if (context->regs[REG_MODE_4] & BIT_INTERLACE)
+	{
+		context->framebuf = context->framebuf == context->oddbuf ? context->evenbuf : context->oddbuf;
+	}
 }
 
 int render_joystick_num_buttons(int joystick)
@@ -321,8 +408,8 @@
 		}
 	}
 	render_context(context);
-	
-	
+
+
 	//TODO: Figure out why this causes segfaults
 	/*frame_counter++;
 	if ((last_frame - start) > 1000) {