From 6c3401b8a2ce7a2dfe21a253f840f286088b1921 Mon Sep 17 00:00:00 2001
From: Andreas Baumann <mail@andreasbaumann.cc>
Date: Sun, 22 Nov 2020 20:38:51 +0100
Subject: more work on emulator

---
 emu/emul.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 117 insertions(+)
 create mode 100644 emu/emul.c

(limited to 'emu/emul.c')

diff --git a/emu/emul.c b/emu/emul.c
new file mode 100644
index 0000000..dc7453b
--- /dev/null
+++ b/emu/emul.c
@@ -0,0 +1,117 @@
+#include "emul.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+void emul_init( emul_t *emul, cpu_6502_t *cpu, memory_t *memory )
+{
+	emul->cpu = cpu;
+	emul->memory = memory;
+	emul->gui = false;
+}
+
+void emul_start( emul_t *emul )
+{
+	if( emul->gui ) {
+#ifdef WITH_GUI
+		int rt = SDL_Init( SDL_INIT_TIMER | SDL_INIT_AUDIO | SDL_INIT_VIDEO );
+		if( rt < 0 ) {
+			fprintf( stderr, "ERROR: SDL_Init failed: %s\n", SDL_GetError( ) );
+			exit( EXIT_FAILURE );
+		}
+		atexit( SDL_Quit );
+		SDL_ShowCursor( SDL_ENABLE );
+		
+		int display = -1;
+		SDL_Rect display_rect;
+		for( int i = 0; i < SDL_GetNumVideoDisplays( ); i++ ) {
+			SDL_Rect rect;
+			if( SDL_GetDisplayBounds( i, &rect ) == 0 ) {
+				fprintf( stderr, "INFO: display %d has dimensions %dx%d\n",
+					i, rect.w, rect.h );
+				display = i;
+				display_rect = rect;
+			} else {
+				fprintf( stderr, "ERROR: SDL_GetDisplayBounds failed: %s\n", SDL_GetError( ) );
+				exit( EXIT_FAILURE );
+			}
+		}
+		if( display < 0 ) {
+			fprintf( stderr, "ERROR: no video display found\n" );
+			exit( EXIT_FAILURE );
+		}
+		
+		emul->window = SDL_CreateWindow( "6502 emu",  
+			SDL_WINDOWPOS_UNDEFINED_DISPLAY( display ),
+			SDL_WINDOWPOS_UNDEFINED_DISPLAY( display ),
+			600, 250, 0 );
+		if( emul->window == NULL ) {
+			fprintf( stderr, "ERROR: SDL_CreateWindow failed: %s\n", SDL_GetError( ) );
+			exit( EXIT_FAILURE );
+		}
+
+		emul->renderer = SDL_CreateRenderer( emul->window, -1, 0 );
+		if( emul->renderer == NULL ) {
+			fprintf( stderr, "ERROR: SDL_Renderer failed: %s\n", SDL_GetError( ) );
+			exit( EXIT_FAILURE );
+		}
+		
+		SDL_ShowWindow( emul->window );
+		SDL_SetRenderDrawColor( emul->renderer, 0, 0, 0, 255 );
+		SDL_RenderClear( emul->renderer );
+		
+		emul->background_image = SDL_LoadBMP( "../other/breadboard.bmp" );
+		emul->background_texture = SDL_CreateTextureFromSurface( emul->renderer, emul->background_image );
+		SDL_RenderCopy( emul->renderer, emul->background_texture, NULL, NULL );
+		
+		SDL_RenderPresent( emul->renderer );
+#else
+		fprintf( stderr, "WARN: gui enabled and not compiled with WITH_GUI (SDL2)\n" );
+#endif
+	}
+}
+
+void emul_run( emul_t *emul )
+{
+#ifdef WITH_GUI
+	if( emul->gui ) {
+		SDL_Event event;
+		bool done = false;
+		while( !done ) {
+			uint32_t frame_start = SDL_GetTicks( );
+			
+			SDL_PollEvent( &event );
+			
+			switch( event.type ) {
+				case SDL_QUIT:
+					done = true;
+					break;
+			}
+			
+			cpu_6502_run( emul->cpu, CPU_FREQUENCY / DISPLAY_FPS );
+			
+			cpu_6502_print_state( emul->cpu, 0 );
+			SDL_RenderCopy( emul->renderer, emul->background_texture, NULL, NULL );
+			SDL_RenderPresent( emul->renderer );
+
+			uint32_t frame_end = SDL_GetTicks( );
+			int delay = frame_start + 1000 / DISPLAY_FPS - frame_end;
+			if( delay > 0 ) {
+				SDL_Delay( delay );
+			}
+		}
+	} else {
+		cpu_6502_run( emul->cpu, 100 );
+	}
+#else
+	cpu_6502_run( emul->cpu, 100 );
+#endif
+}
+
+void emul_free( emul_t *emul )
+{
+	SDL_DestroyTexture( emul->background_texture );
+	SDL_FreeSurface( emul->background_image );
+	SDL_DestroyRenderer( emul->renderer );
+	SDL_DestroyWindow( emul->window );
+}
-- 
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