Various changes

- add release build
- control framerate
- fix bug that caused camera to shake
- enable double-buffering and VSync

.gitignore

@@ -1,3 +1,4 @@
 obj/*
 Game
+Release
 *.xcf

makefile

@@ -2,17 +2,19 @@ INC = include
 OBJ = obj
 SRC = src
 EXE = Game
+REL = Release
 
 CC = gcc
 CFLAGS = -w -ggdb -I$(INC)
 LIBS = -lGLEW -lGLU -lGL -lSDL2 -lcglm -lz -lm
+RELFLAGS = -O3 -s
 
 OBJFILES := $(patsubst $(SRC)/%.c, $(OBJ)/%.o, $(shell find $(SRC) -name '*.c'))
 OBJDIRS := $(patsubst $(SRC)%, $(OBJ)%, $(shell find $(SRC) -type d))
 CLEANDIRS := $(addsuffix /.clean, $(OBJDIRS));
 
 # Explicit targets
-.PHONY: all clean
+.PHONY: all release clean
 .DEFAULT_GOAL := all
 
 # Build executable
@@ -28,8 +30,12 @@ $(OBJ)/%.o: $(SRC)/%.c | $(OBJDIRS)
 $(OBJDIRS):
 	mkdir -p $@
 
+release: $(REL)
+$(REL): $(OBJFILES) | $(OBJDIRS)
+	$(CC) -o $@ $^ $(CFLAGS) $(LIBS) $(RELFLAGS)
+
 # Delete previously built files
 clean: $(CLEANDIRS)
-	rm -f $(EXE)
+	rm -f $(EXE) $(REL)
 %.clean:
 	rm -f $**.o

src/game.c

@@ -18,6 +18,26 @@ GameState *Game_New()
 
 void Game_Update(GameState *gs)
 {
+	const int fps = 60;
+	uint64_t currentTicks = SDL_GetTicks64();
+	uint64_t targetTicks = gs->previousTicks + (1000 / fps);
+	int32_t waitTicks = targetTicks - currentTicks;
+	
+	if (waitTicks > 0)
+	{
+		SDL_Delay(waitTicks);
+		currentTicks = SDL_GetTicks64();
+	}
+	else if (waitTicks <= -5)
+	{
+		printf("frame is late by %d ms\n", -waitTicks);
+	}
+	
+	uint32_t delta = currentTicks - gs->previousTicks;
+	gs->previousTicks = currentTicks;
+	
+	Camera_UpdateVectors(&gs->camera);
+	
 	const float speed = 0.3f;
 	vec3 move, front, right;
 	glm_vec3_zero(move);
@@ -47,7 +67,6 @@ void Game_Update(GameState *gs)
 	glm_vec3_add(target->position, displacement, gs->camera.position);
 	
 	Camera_UpdateVectors(&gs->camera);
-	SDL_Delay(5);
 }
 
 void Game_Destroy(GameState *gs)

src/game.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <stdbool.h>
+#include <stdint.h>
 #include "SDL2/SDL.h"
 #include "cglm/cglm.h"
 #include "camera.h"
@@ -20,6 +21,7 @@ typedef struct
 typedef struct
 {
 	bool running;
+	uint64_t previousTicks;
 	InputState input;
 	SDL_Window *window;
 	SDL_GLContext *glContext;

src/render.c

@@ -216,11 +216,15 @@ bool Render_Init(GameState *gs)
 	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 4);
 	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 5);
 	SDL_GL_SetAttribute(SDL_GL_STENCIL_SIZE, 8);
+	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
 	
 	gs->window = SDL_CreateWindow("Sandbox", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1920, 1080, SDL_WINDOW_OPENGL | SDL_WINDOW_RESIZABLE);;
 	gs->glContext = SDL_GL_CreateContext(gs->window);
 	printf("Created OpenGL window.\n");
 	
+	if (SDL_GL_SetSwapInterval(1) == 0) printf("Enabled VSync.\n");
+	else printf("Failed to enable VSync. SDL Error: %s\n", SDL_GetError());
+	
 	glewInit();
 	gs->shaderProgramId = LoadShaders("./res/glsl/vertex.glsl", "./res/glsl/fragment.glsl");
 	gs->modelShaderProgramId = LoadShaders("./res/glsl/model_vertex.glsl", "./res/glsl/fragment.glsl");