GDB Adventures

src/lorenz.c

@@ -13,7 +13,20 @@ float pos[3] = {0.0f, 0.0f, 0.0f};
 float rho=28.0;
 float sigma=10.0;
 float beta=8.0/3.0;
+void lorenzStep(float next[3], vec3 prev, float dt) {
+	float x, y, z, dx, dy, dz;
+	x = prev[0];
+	y = prev[1];
+	z = prev[2];
 
+	dx = (sigma * (y-x))*dt;
+	dy = (x * (rho - z) -y)*dt;
+	dz = (x*y - beta*z)*dt;
+
+	next[0] = prev[0] + dx;
+	next[1] = prev[1] + dy;
+	next[2] = prev[2] + dz;
+}
 
 int main(int argc, char *argv[]) {
 	
@@ -21,14 +34,9 @@ int main(int argc, char *argv[]) {
 	window = initOpenGL();
 	glfwSetKeyCallback(window, &key_pressed);
 	
-	
 	// CreateShader
-	char* vertex = "assets/shaders/vertex.glsl\0";
-	char* fragment = "assets/shaders/fragment.glsl\0";
 	unsigned int shader1;
-	shader1 = createShader(vertex, fragment);
-
-	int projectionLoc = glGetUniformLocation(shader1, "proj");
+	shader1 = createShader("assets/shaders/vertex.glsl\0", "assets/shaders/fragment.glsl\0");
 
 	// Initialise VBO and VAO
 	unsigned int VAO, VBO;
@@ -37,50 +45,42 @@ int main(int argc, char *argv[]) {
 		
 	glBindVertexArray(VAO);
 	glBindBuffer(GL_ARRAY_BUFFER, VBO);
-	glBufferData(GL_ARRAY_BUFFER, sizeof(vec3), NULL, GL_DYNAMIC_DRAW);
+	glBufferData(GL_ARRAY_BUFFER, 3000* sizeof(vec3), NULL, GL_STREAM_DRAW);
 	glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 3 * sizeof(float), (void*)0 );
 	glEnableVertexAttribArray(0);
 
-	vec3 vertices[3000];
-	int i=0;
-	float dx, dy, dz, dt=0.001;
-	vertices[0][0]=0.01;
-	vertices[0][1]=0.01;
-	vertices[0][2]=0.01;
-
-
+	// Projection Matrix
 	mat4x4 proj;
+	mat4x4_identity(proj);
 	mat4x4_ortho(proj, 0.0, 400.0, 0.0, 400.0, 0.1, 100.0);
 
+	// Uniform Projection Matrix
+	glUseProgram(shader1);
+	int projectionLoc = glGetUniformLocation(shader1, "proj");
+	glUniformMatrix4fv(projectionLoc, 1, GL_FALSE, *proj);
+	
+	vec3* lorenzPoints = malloc(3000 * sizeof(vec3));
+	memset(lorenzPoints, 0, 3000 * sizeof(vec3));
+	vec3 initial = {0.1f, 0.1f, 0.1f};
+	memcpy(lorenzPoints, initial, sizeof(vec3));
+
+	int i=1;
 	while(!glfwWindowShouldClose(window)) {
 		glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
 		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-	
 		glUseProgram(shader1);
 		
-		//glUniformMatrix4fv(projectionLoc, 1, GL_FALSE, *proj);
+		float increment = 0.1* (float)i;
+		float next[3] = {increment, increment, increment};
+		//lorenzStep(next, lorenzPoints[i], 0.01f);
+		memcpy(lorenzPoints[i++], next, sizeof(vec3));
 
-		if(i<3000) {
-			float x, y, z;
-			x = vertices[i][0];
-			y = vertices[i][1];
-			z = vertices[i][2];
 
-			printf("%i %f %f %f\n", i, x, y, z);
-
-			dx = (sigma * (y-x))*dt;
-			dy = (x * (rho - z) -y)*dt;
-			dz = (x*y - beta*z)*dt;
-
-			i++;
-			vertices[i][0] = x+dx;
-			vertices[i][1] = y+dy;
-			vertices[i][2] = z+dz;
-			
-			glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(vec3), vertices[i]);
-		}
-		glDrawArrays(GL_POINTS, 0, 1);
+		float* buff = glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY);
+		memcpy(buff, lorenzPoints, i * sizeof(vec3));
+		glUnmapBuffer(GL_ARRAY_BUFFER);
 
+		glDrawArrays(GL_LINE_STRIP, 0, i);
 		glfwSwapBuffers(window);
 		glfwPollEvents();
 		processInput();