add base code for windowing and opengl crt-shader.

1 files changed, 134 insertions, 0 deletions

diff --git a/base/state.c b/base/state.c
new file mode 100644
index 0000000..f883d64
--- /dev/null
+++ b/base/state.c
@@ -0,0 +1,134 @@
+
+#define BUFFER_WIDTH  2048
+#define BUFFER_HEIGHT 1024
+#define FPS 50
+#ifdef _WIN32
+	#define SLEEP_MARGIN_NS 330000 // 0.33ms (Windows timing functionality is utter garbage)
+#else
+	#define SLEEP_MARGIN_NS 100000 // 0.1ms
+#endif
+
+#define ONE_SECOND_NS 1000000000
+#define FRAMETIME (ONE_SECOND_NS / FPS)
+
+#define SCREEN_WIDTH 360
+#define SCREEN_HEIGHT 270
+
+uint32_t buffer[BUFFER_WIDTH * BUFFER_HEIGHT] __attribute__((section(".bss"), aligned(4096)));
+uint32_t display_buffer[SCREEN_WIDTH * SCREEN_HEIGHT] __attribute__((section(".bss"), aligned(4096)));
+
+#ifdef PROFILER
+#define MAX_PROFILING_ENTRIES (64)
+
+struct function_cycles {
+	const char *name;
+	uint64_t cycles;
+	uint32_t count;
+};
+
+struct debug_state {
+	struct function_cycles timings[MAX_PROFILING_ENTRIES];
+};
+#endif
+
+struct state {
+	// Pointers (8-byte aligned)
+	uint32_t *display_buffer;
+	struct { int32_t x, y, w, h; } viewport;
+	int32_t mouse_dx;
+	int32_t mouse_dy;
+	int32_t filter_override;					// Manual override: -1 = automatic, 0 = off, 1 = on
+	float filter_frequency;						// Frequency in Hz for squarewave toggle
+
+	float contrast;
+	float saturation;
+	float brightness;
+	float tone_data[4];
+
+	// OpenGL Objects
+	GLuint shader_program;
+	GLuint texture;
+	GLuint vao;
+	GLuint vbo;
+	GLuint ebo;
+
+	// Shader Uniforms
+	GLuint uniform_resolution;
+	GLuint uniform_src_image_size;
+	GLuint uniform_brightness;
+	GLuint uniform_tone;
+	GLuint uniform_crt_emulation;
+	GLuint uniform_sampler_location;
+	GLuint uniform_tex_bounds;
+
+	// Rendering & Dynamic Resolution
+	uint32_t screen_width;	// for the debugger
+	uint32_t screen_height;	// for the debugger
+	uint32_t render_width;	// The actual remake resolution (e.g., 360)
+	uint32_t render_height;	// The actual remake resolution (e.g., 270)
+	uint32_t render_x;		// X position inside BUFFER_WIDTH (to track centering)
+	uint32_t render_y;		// Y position inside BUFFER_HEIGHT (to track centering)
+	uint32_t frame_number;
+	size_t total_allocated;
+	bool freewheeling;
+	bool toggle_crt_emulation;
+	bool fullscreen;
+#ifdef PROFILER
+	bool overlay;
+	struct debug_state debug;
+#endif
+};
+
+struct state state;
+
+static struct remake_callbacks *current_part = 0;
+static void render_callback();
+static void audio_callback(int16_t *audio_buffer, size_t frames);
+static void init_callback();
+
+#ifndef PROFILER
+#define PROFILE_NAMED(name)
+#define PROFILE_FUNCTION()
+
+#else
+
+struct profiling_context {
+	uint32_t func_id;
+};
+
+__attribute__((section(".bss")))
+uint8_t debug_line_buffer[MAX_PROFILING_ENTRIES * 256];	// NOTE(peter): for storing all performance strings in an array to print to the debug-output
+
+__attribute__((always_inline, hot))
+static inline uint64_t read_tsc() {
+	unsigned int aux;
+	uint64_t result = __rdtscp(&aux);
+	return result;
+}
+
+__attribute__((always_inline, hot))
+static inline void end_profiling(struct profiling_context *ctx) __attribute__((unused));
+__attribute__((always_inline, hot))
+static inline void end_profiling(struct profiling_context *ctx) {
+	state.debug.timings[ctx->func_id].cycles += read_tsc();
+	state.debug.timings[ctx->func_id].count++;
+}
+
+#define PROFILE_NAMED(name)																			\
+	uint32_t func_id = __COUNTER__;																	\
+	if((state).debug.timings[func_id].count == 0)												\
+		(state).debug.timings[func_id] = (struct function_cycles){(name), 0, 0};		\
+	(state).debug.timings[func_id].cycles -= read_tsc();										\
+	struct profiling_context ctx __attribute__((cleanup(end_profiling))) = { func_id };
+
+#define PROFILE_FUNCTION()																				\
+	uint32_t func_id = __COUNTER__;																	\
+	if((state).debug.timings[func_id].count == 0)												\
+		(state).debug.timings[func_id] = (struct function_cycles){__func__, 0, 0};		\
+	(state).debug.timings[func_id].cycles -= read_tsc();										\
+	struct profiling_context ctx __attribute__((cleanup(end_profiling))) = { func_id };
+#endif
+
+
+
+