Camera follows object in 3rd person

src/camera.c

@@ -4,7 +4,7 @@
 void Camera_Init(Camera* c)
 {
 	c->position[0] = 5.0f;
-	c->position[1] = 0.0f;
+	c->position[1] = 8.0f;
 	c->position[2] = 0.0f;
 	c->width[0] = 0.6f;
 	c->width[1] = 5.8f;

src/game.c

@@ -7,7 +7,8 @@
 
 GameState *Game_New()
 {
-	GameState *gs = calloc(1, sizeof(GameState));
+	GameState *gs = calloc(1, sizeof(GameState) + (2 * sizeof(Shape**)));
+	gs->shapes = (void*)(gs + 1);
 	
 	if (!Render_Init(gs)) return NULL;
 	
@@ -26,7 +27,12 @@ void Game_Update(GameState *gs)
 	else if (gs->input.d) move[1] = -speed;
 	if (gs->input.q) move[2] = speed;
 	else if (gs->input.e) move[2] = -speed;
-	glm_vec3_add(gs->camera.position, move, gs->camera.position);
+	
+	ShapeInstance *target = &(gs->shapes[0]->instances[2]);
+	vec3 displacement;
+	glm_vec3_scale(gs->camera.front, -10.0, displacement);
+	glm_vec3_add(target->position, move, target->position);
+	glm_vec3_add(target->position, displacement, gs->camera.position);
 	
 	Camera_UpdateVectors(&gs->camera);
 	SDL_Delay(5);

src/game.h

@@ -25,7 +25,8 @@ typedef struct
 	GLuint textureId;
 	int shaderProgramId;
 	Camera camera;
-	Shape *testShape;
+	Shape **shapes;
+	int numShapes;
 	mat4 projMatrix;
 	mat4 viewMatrix;
 } GameState;

src/render.c

@@ -227,6 +227,7 @@ bool Render_Init(GameState *gs)
 	if (gs->shaderProgramId < 0)
 	{
 		printf("Failed to load shaders.\n");
+		return false;
 	}
 	
 	glEnable(GL_DEPTH_TEST);
@@ -236,17 +237,32 @@ bool Render_Init(GameState *gs)
 	glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 	printf("Initialized OpenGL.\n");
 	
+	gs->numShapes = 2;
+	
 	Shape *shape = Shape_MakePyramid(5);
-	gs->testShape = shape;
+	gs->shapes[0] = shape;
 	glGenVertexArrays(1, &shape->VAO);
 	glGenBuffers(1, &shape->VBO);
 	glGenBuffers(1, &shape->IBO);
 	glGenBuffers(1, &shape->EBO);
+	printf("Created shape 0.\n");
+	
+	shape = Shape_MakePlane();
+	gs->shapes[1] = shape;
+	glGenVertexArrays(1, &shape->VAO);
+	glGenBuffers(1, &shape->VBO);
+	glGenBuffers(1, &shape->IBO);
+	glGenBuffers(1, &shape->EBO);
+	printf("Created shape 1.\n");
 	
 	LoadTexture(gs);
+	printf("Loaded textures.\n");
 	Camera_Init(&gs->camera);
 	
-	InitShapeBuffers(gs->testShape);
+	InitShapeBuffers(gs->shapes[0]);
+	InitShapeBuffers(gs->shapes[1]);
+	printf("Initialized buffers.\n");
+	return true;
 }
 
 void Render_Destroy(GameState *gs)
@@ -302,35 +318,38 @@ void Render_Draw(GameState *gs)
 	glBindTexture(GL_TEXTURE_2D, gs->textureId);
 	vec3 scale = { 0, 0, 0 };
 	
-	Shape *shape = gs->testShape;
+	for (int i = 0; i < gs->numShapes; i++)
-	glBindVertexArray(shape->VAO);
-	
-	// apply transformations to each instance
-	for (int j = 0; j < shape->numInstances; j++)
 	{
-		ShapeInstance* instance = shape->instances + j;
+		Shape *shape = gs->shapes[i];
-		mat4* matrix = (void*)(shape->instanceData + (j * 17) + 1);
+		glBindVertexArray(shape->VAO);
-		mat4 tempMat;
-		glm_mat4_identity(tempMat);
 		
-		glm_translate(tempMat, instance->position);
+		// apply transformations to each instance
-		glm_rotate_x(tempMat, instance->rotation[0], tempMat);
+		for (int j = 0; j < shape->numInstances; j++)
-		glm_rotate_y(tempMat, instance->rotation[1], tempMat);
+		{
-		glm_rotate_z(tempMat, instance->rotation[2], tempMat);
+			ShapeInstance* instance = shape->instances + j;
+			mat4* matrix = (void*)(shape->instanceData + (j * 17) + 1);
+			mat4 tempMat;
+			glm_mat4_identity(tempMat);
 			
-		scale[0] = instance->scale;
+			glm_translate(tempMat, instance->position);
-		scale[1] = instance->scale;
+			glm_rotate_x(tempMat, instance->rotation[0], tempMat);
-		scale[2] = instance->scale;
+			glm_rotate_y(tempMat, instance->rotation[1], tempMat);
-		glm_scale(tempMat, scale);
+			glm_rotate_z(tempMat, instance->rotation[2], tempMat);
 			
-		memcpy(matrix, tempMat, sizeof(mat4));
+			scale[0] = instance->scale;
+			scale[1] = instance->scale;
+			scale[2] = instance->scale;
+			glm_scale(tempMat, scale);
+			
+			memcpy(matrix, tempMat, sizeof(mat4));
+		}
+		
+		// re-buffer the instance data because transformations may have changed
+		glBindBuffer(GL_ARRAY_BUFFER, shape->IBO);
+		glBufferData(GL_ARRAY_BUFFER, shape->numInstances * SHAPE_INSTANCE_SIZE, shape->instanceData, GL_DYNAMIC_DRAW);
+		
+		glDrawElementsInstanced(GL_TRIANGLES, shape->numIndices, GL_UNSIGNED_SHORT, 0, shape->numInstances);
 	}
 	
-	// re-buffer the instance data because transformations may have changed
-	glBindBuffer(GL_ARRAY_BUFFER, shape->IBO);
-	glBufferData(GL_ARRAY_BUFFER, shape->numInstances * SHAPE_INSTANCE_SIZE, shape->instanceData, GL_DYNAMIC_DRAW);
-	
-	glDrawElementsInstanced(GL_TRIANGLES, shape->numIndices, GL_UNSIGNED_SHORT, 0, shape->numInstances);
-	
 	SDL_GL_SwapWindow(gs->window);
 }

src/shape.c

@@ -63,8 +63,8 @@ Shape *Shape_MakePyramid(int numInstances)
 	{
 		ShapeInstance *instance = shape->instances + i;
 		instance->position[0] = 0.0f;
-		instance->position[0] = 0.0f;
+		instance->position[1] = 3.0f;
-		instance->position[0] = (5.0f * i) - 10.0;
+		instance->position[2] = (5.0f * i) - 10.0f;
 		instance->scale = 1.0f;
 		instance->collisionRadius = 1.0f;
 		glm_vec3_zero(instance->velocity);
@@ -77,6 +77,54 @@ Shape *Shape_MakePyramid(int numInstances)
 	return shape;
 }
 
+Shape *Shape_MakePlane()
+{
+	GLfloat vertices[] =
+	{
+		-30.0f,  0.0f, -30.0f,		0.0f, 0.0f,
+		-30.0f,  0.0f,  30.0f,		0.0f, 1.0f,
+		 30.0f,  0.0f,  30.0f,		1.0f, 1.0f,
+		 30.0f,  0.0f, -30.0f,		1.0f, 0.0f,
+	};
+	
+	GLushort indices[] =
+	{
+		1, 2, 0,
+		2, 3, 0
+	};
+	
+	size_t numBytesVertices = sizeof(vertices);
+	size_t numBytesIndices = sizeof(indices);
+	
+	Shape *shape = malloc(sizeof(Shape) + numBytesVertices + numBytesIndices);
+	void *tempPtr = (void*)(shape + 1);
+	shape->vertices = tempPtr;
+	shape->numVertices = numBytesVertices / sizeof(vertices[0]);
+	shape->indices = tempPtr + numBytesVertices;
+	shape->numIndices = numBytesIndices / sizeof(indices[0]);
+	
+	memcpy(shape->vertices, vertices, numBytesVertices);
+	memcpy(shape->indices, indices, numBytesIndices);
+	
+	shape->instances = calloc(1, sizeof(ShapeInstance) + SHAPE_INSTANCE_SIZE);
+	shape->instanceData = (void*)(shape->instances + 1);
+	shape->numInstances = 1;
+	
+	ShapeInstance *instance = shape->instances;
+	instance->position[0] = 0.0f;
+	instance->position[1] = 0.0f;
+	instance->position[2] = 0.0f;
+	instance->scale = 1.0f;
+	instance->collisionRadius = 1.0f;
+	glm_vec3_zero(instance->velocity);
+	glm_vec3_zero(instance->rotation);
+	float *textureId = shape->instanceData + (0 * 17);
+	*textureId = 5;
+	mat4 *matrix = (void*)(textureId + 1);
+	
+	return shape;
+}
+
 void *Shape_Destroy(Shape *shape)
 {
 	free(shape);

src/shape.h

@@ -15,7 +15,6 @@ typedef struct
 	vec3 velocity;
 	float scale;
 	float collisionRadius;
-	
 } ShapeInstance;
 
 typedef struct
@@ -35,3 +34,4 @@ typedef struct
 } Shape;
 
 Shape *Shape_MakePyramid(int numInstances);
+Shape *Shape_MakePlane();