Made individual pixel rendering more efficient

src/main.c

@@ -31,17 +31,20 @@ uint8_t fpsCount = 0;
 uint8_t displayMmap = 0;
 uint8_t documentReload = 0;
 uint8_t randomize = 0;
+uint8_t trueViewport = 0;
 
 uint8_t fpsStore = 60;
 uint8_t FPS = 30;
-uint8_t cpuHealth;
+uint8_t cpuHealth = 100;
+uint32_t videoStore = 0;
+uint32_t videoUpdates = 0;
 
 unsigned long cpuTicks = 0;
 unsigned long tickTrigger = 0;
 
 char debugString[512];
 char snapshotFile[32];
-char *reloadExecute;
+char *reloadExecute = 0;
 char *inputFile;
 char *displaySpeed;
 
@@ -109,6 +112,7 @@ void fetchArgs(int argc, char *argv[]){
         else if (!strcmp(argv[i], "--script"))          reloadExecute = argv[++i];
         else if (!strcmp(argv[i], "--resizable"))       WINMODE |= SDL_WINDOW_RESIZABLE;
         else if (!strcmp(argv[i], "--randomize"))       randomize = 1;
+        else if (!strcmp(argv[i], "--true-viewport"))   trueViewport = 1;
         else {
             inputFile = argv[i];
             if (openFile()){
@@ -132,7 +136,6 @@ int main(int argc, char *argv[]){
         pollEvents();
         
         fpsCount++; 
-        updateVideo();
     
         if (!singleStep && !halt){
             for (int i = 0; i < ((float)cpuSpeed / (float)fpsStore); i++) {
@@ -142,32 +145,32 @@ int main(int argc, char *argv[]){
             irq6502();
         }
         
+        /* Ticker before menu draw */
         if ((unsigned)time(NULL) != tickTrigger){            
-            tickTrigger = (unsigned)time(NULL);
-            
             cpuHealth = (uint8_t)((cpuTicks / (float)cpuSpeed) * 100.);
             cpuTicks = 0;
             
             fpsStore = fpsCount; fpsCount = 0;
             
-            /* Refresh entire video buffer */
-            videoModified = 1;
+            /* Refresh entire video field every second */
+            updateVideo();
         }
         
         
         uint16_t vStack = 16;
     
         if (halt) {
-            drawString("!CPU Haltet!", renderMemory, 
+            drawString("!CPU HALTET!", renderMemory, 
                 SDL_X_SIZE, 0x000000FF, time(NULL) % 2 ? 0xAAAAAAFF : 0xFFFFFFFF, 16, vStack, 1);
             
             vStack += (FONT_HEIGHT * 2);
         } if (showDebug){
-            sprintf(debugString, "LOADED BINARY: \"%s\"\nSCREENSIZE: %dx%d\nFPS: %d\nSCALE: %d", inputFile, SDL_X_SIZE, SDL_Y_SIZE, fpsStore, (int)displayScale);
+            sprintf(debugString, "LOADED BINARY: \"%s\"\nSCREENSIZE: %dx%d\nFPS: %d\nSCALE: %d\nVIDEO UPDATES: %d", 
+                        inputFile, SDL_X_SIZE, SDL_Y_SIZE, fpsStore, (int)displayScale, videoStore);
             drawString(debugString, renderMemory, 
                     SDL_X_SIZE, 0x000000FF, 0xAAAAAAFF, 16, vStack, 1);
             
-            vStack += (FONT_HEIGHT * 4);
+            vStack += (FONT_HEIGHT * 5);
 
             sprintf(debugString, "CPU: %d%% @ %s", cpuHealth, displaySpeed);
             drawString(debugString, renderMemory, 
@@ -196,6 +199,15 @@ int main(int argc, char *argv[]){
         }
         
         SDL_RenderPresent(renderer);
+        
+        
+        /* Ticker after menu draw */
+        if ((unsigned)time(NULL) != tickTrigger){
+            tickTrigger = (unsigned)time(NULL);
+            
+            videoStore = videoUpdates;
+            videoUpdates = 0;
+        }
     }
 
     return EXIT_SUCCESS;

src/memory.c

@@ -2,6 +2,7 @@
 #include "config.h"
 
 extern void scanKeyboard();
+extern void updateVideo();
 extern void writeVideo();
 extern uint8_t readVideo();
 extern uint8_t videoX;
@@ -64,6 +65,7 @@ void write6502(uint16_t address, uint8_t value){
 					break;
 				case 2:			/* Video M Register */
 					videoMode = value;
+					updateVideo();
 					break;
 				case 3:			/* Video A Register */
 					videoA = value;

src/video.c

@@ -5,12 +5,10 @@
 #define HIGHCOLOR 255
 #define LOWCOLOR 96
 
+extern uint32_t videoUpdates;
 extern float displayScale;
 extern uint8_t randomize;
 
-/* Public Variables */
-int8_t videoModified;
-
 /* Hardware-like Registers */
 uint8_t videoX;
 uint8_t videoY;
@@ -47,22 +45,10 @@ void updatePalette(){
 }
 
 void initVideo(){
-	videoModified = 1;
 	videoMode = 0x01;
 	updatePalette();
 	
-	if (randomize) {
-		for (int i = 0; i < 0x8000; i++) videoMemory[i] = rand();
-	}
-}
-
-void writeVideo(){
-	videoMemory[videoX + (videoY * 128)] = videoA;
-	videoModified = 1;
-}
-
-uint8_t readVideo(){
-	return videoMemory[videoX + (videoY * 128)];
+	if (randomize) for (int i = 0; i < 0x8000; i++) videoMemory[i] = rand();
 }
 
 void setPixels(uint8_t x, uint8_t y){
@@ -84,6 +70,7 @@ void setPixels(uint8_t x, uint8_t y){
 		videoColorValue = videoMemory[(((y & 0xF8) >> 3) << 7) + (x | 0x40)];
 	}
 	else {
+		/* Bitmapped Graphics mode fetch */
 		videoValue = videoMemory[(y * 128) + x];
 		videoColorValue = videoMemory[(y * 128) + (x | 0x40)];
 	}
@@ -97,13 +84,35 @@ void setPixels(uint8_t x, uint8_t y){
 }
 
 void updateVideo(){
-	if (videoModified){		
 	for (uint16_t y = 0; y < 256; y++){
 		for (uint8_t x = 0; x < 48; x++){
 			setPixels(x, (uint8_t)y);
 		}
 	}
+}
 
-		videoModified = 0;
+void writeVideo(){
+	/* Update actual video memory */
+	videoMemory[videoX + (videoY * 128)] = videoA;
+	
+	/* X has to be in a viewable location and must not be in font */
+	if ((videoX > 0x3F || videoX < 0x30) && videoX < 0x70){
+		
+		if ((videoMode & 0x01) == 0) {
+			/* For text mode, update the entire block */
+			for (uint8_t i = 0; i < 8; i++){
+				setPixels((videoX & 0b00111111), (uint8_t)((videoY*8) + i));
+			}
+			videoUpdates++;
+		} else {
+			/* Graphics mode, just update line */
+			setPixels(videoX & 0b00111111, videoY);
+			videoUpdates++;
 		}
 	}
+}
+
+uint8_t readVideo(){
+	return videoMemory[videoX + (videoY * 128)];
+}
+