Reorgani

SDL2-Bits-And-Pieces/SDL2-Notes.org

@@ -1,14 +1,9 @@
-* Experiments 1-3: Basics:
-These experiments are mostly about learning to put things on the screen.
 - Experiment 01: A "Radar" which tracks the position of the mouse, drawn using
   SDL2 primitives and a loaded image.
 - Experiment 02: A stripped down version of the first experiment, using keyboard
   input to move the cursor.
 - Experiment 03: An improved version of 02, which uses movement acceleration to
   make it feel better to use.
-  
-* Experiment 4-8: Gravity
-These experiments are based around developing a gravity simulation.
 - Experiment 04: An example of simple gravity and bouncing simulation.
 - Experiment 05: A "Spacewar" style gravity simulation, with a ship orbiting a star.
 - Experiment 06: A modified version of 05, using delta-time scaling so it is
@@ -19,3 +14,9 @@ These experiments are based around developing a gravity simulation.
   "star." Fun to play aronud with.
 - Experiment 09: A version of the simulation where the ship can be steered and
   accelerated. 
+- Experiment 10: A version of the simulation where the ship has been given a
+  sprite. 
+- Experiment 11: A version of the simulation where the sprite animates while
+  accelerating. 
+- Experiment 12: A version of the simulation where the screen scrolls around
+  with the movement of the ship.

SDL2-Bits-And-Pieces/SDL2-UDP-Experiment-01-controller.c

@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+typedef struct position
+{
+	int x;
+	int y;		
+} position;
+
+int main()
+{
+	// Create the socket:
+	int socketFileDesc = socket(AF_INET, SOCK_DGRAM, 0);
+	if (socketFileDesc < 0)
+	{
+		fprintf(stderr, "\tSocket Creation is:\t\033[33;40mRED.\033[0m Aborting launch.\n");
+		exit(0);
+	}
+	printf("\tSocket Creation is:\t\033[32;40mGREEN.\033[0m\n");
+
+	// Create and fill the information needed to bind to the socket:
+	struct sockaddr_in serverAddress;
+	serverAddress.sin_family = AF_INET; // IPv4
+	serverAddress.sin_addr.s_addr = inet_addr("127.0.0.1");
+	serverAddress.sin_port = htons(12000);
+
+	position posToSend = {0, 0};
+
+	// Send data at the server:
+	while (1)
+	{
+		scanf("%d %d", &posToSend.x, &posToSend.y);
+		sendto(socketFileDesc, &posToSend, sizeof(posToSend), 0, (const struct sockaddr *)&serverAddress, sizeof(serverAddress));
+	}
+}

SDL2-Bits-And-Pieces/SDL2-UDP-Experiment-01.c

@@ -0,0 +1,147 @@
+// SDL/UDP Experiment 01, Barra Ó Catháin.
+// =======================================
+#include <SDL2/SDL.h>
+#include <SDL2/SDL_image.h>
+#include <SDL2/SDL_timer.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+void DrawCircle(SDL_Renderer * renderer, int32_t centreX, int32_t centreY, int32_t radius)
+{
+   const int32_t diameter = (radius * 2);
+
+   int32_t x = (radius - 1);
+   int32_t y = 0;
+   int32_t tx = 1;
+   int32_t ty = 1;
+   int32_t error = (tx - diameter);
+
+   while (x >= y)
+   {
+	 //  Each of the following renders an octant of the circle
+      SDL_RenderDrawPoint(renderer, centreX + x, centreY - y);
+      SDL_RenderDrawPoint(renderer, centreX + x, centreY + y);
+      SDL_RenderDrawPoint(renderer, centreX - x, centreY - y);
+      SDL_RenderDrawPoint(renderer, centreX - x, centreY + y);
+      SDL_RenderDrawPoint(renderer, centreX + y, centreY - x);
+      SDL_RenderDrawPoint(renderer, centreX + y, centreY + x);
+      SDL_RenderDrawPoint(renderer, centreX - y, centreY - x);
+      SDL_RenderDrawPoint(renderer, centreX - y, centreY + x);
+
+      if (error <= 0)
+      {
+         ++y;
+         error += ty;
+         ty += 2;
+      }
+
+      if (error > 0)
+      {
+         --x;
+         tx += 2;
+         error += (tx - diameter);
+      }
+   }
+}
+
+// Get the largest radius for a circle that can fit in the width and height of a rectangle:
+static inline int getRadius(int width, int height)
+{
+	return (width/2 < height/2) ? width/2 : height/2;
+}
+
+
+int main(int argc, char ** argv)
+{
+	SDL_Event event;
+	int positionX = 0, positionY = 0;
+	uint32_t rendererFlags = SDL_RENDERER_ACCELERATED;
+	
+	// Initialize the SDL library, video, sound, and input:
+	if (SDL_Init(SDL_INIT_EVERYTHING) != 0)
+	{
+		printf("SDL Initialization Error: %s\n", SDL_GetError());
+	}
+	
+	// Create an SDL window and rendering context in that window:
+	SDL_Window * window = SDL_CreateWindow("SDL_TEST", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 640, 640, 0);
+	SDL_Renderer * renderer = SDL_CreateRenderer(window, -1, rendererFlags);
+	
+	// Enable resizing the window:
+	SDL_SetWindowResizable(window, SDL_TRUE);
+
+	// Create the socket:
+	int socketFileDesc = socket(AF_INET, SOCK_DGRAM, 0);
+	if (socketFileDesc < 0)
+	{
+		fprintf(stderr, "\tSocket Creation is:\t\033[33;40mRED.\033[0m Aborting launch.\n");
+		exit(0);
+	}
+	printf("\tSocket Creation is:\t\033[32;40mGREEN.\033[0m\n");
+
+	// Make the socket timeout:
+	struct timeval read_timeout;
+	read_timeout.tv_sec = 0;
+	read_timeout.tv_usec = 10;
+	setsockopt(socketFileDesc, SOL_SOCKET, SO_RCVTIMEO, &read_timeout, sizeof read_timeout);
+	
+	// Create and fill the information needed to bind to the socket:
+	struct sockaddr_in serverAddress;
+	memset(&serverAddress, 0, sizeof(serverAddress));
+	serverAddress.sin_family = AF_INET; // IPv4
+	serverAddress.sin_addr.s_addr = INADDR_ANY;
+	serverAddress.sin_port = htons(12000);
+
+	// Bind to the socket:
+	if (bind(socketFileDesc, (const struct sockaddr *)&serverAddress, sizeof(serverAddress)) < 0)
+    {
+        perror("bind failed");
+        exit(EXIT_FAILURE);
+    }
+
+	// A struct to transfer the position data:
+	typedef struct position
+	{
+		int x;
+		int y;		
+	} position;
+
+	position currentPosition = {0, 0};
+	
+	while (true)
+	{
+		// Receive data from the socket:
+		recvfrom(socketFileDesc, &currentPosition, sizeof(position), 0, NULL, NULL);
+
+		// Set the position to the received one:
+		positionX = currentPosition.x;
+		positionY = currentPosition.y;
+		
+		// Set the colour to black:
+		SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);
+
+		// Clear the screen, filling it with black:
+		SDL_RenderClear(renderer);
+
+		// Set the colour to yellow:
+		SDL_SetRenderDrawColor(renderer, 255, 255, 0, 255);
+		
+		// Draw a circle around the position pointer:
+		DrawCircle(renderer, positionX, positionY, 15);
+
+		// Present the rendered graphics:
+		SDL_RenderPresent(renderer);
+
+		// Delay enough so that we run at 144 frames:
+		SDL_Delay(1000 / 144);
+	}
+	return 0;
+}
+// =============================================================================
+// Local Variables:
+// compile-command: "gcc `sdl2-config --libs --cflags` SDL2-UDP-Experiment-01.c"
+// End: