X-Git-Url: https://git.sesse.net/?p=movit;a=blobdiff_plain;f=main.cpp;h=bbc775271b7d3c46b26caa03f5ed39997d7a0ae0;hp=84837395879a43f10f4a897f772846d3e757966a;hb=05ae48a62f4a507c1eef75b9220f88f2b9fda563;hpb=e61807327b9a1f98f39dd5e1496254905f78e581

diff --git a/main.cpp b/main.cpp
index 8483739..bbc7752 100644
--- a/main.cpp
+++ b/main.cpp
@@ -3,11 +3,11 @@
 
 #define WIDTH 1280
 #define HEIGHT 720
-#define BUFFER_OFFSET(i) ((char *)NULL + (i))
 
 #include <string.h>
 #include <math.h>
 #include <time.h>
+#include <sys/time.h>
 #include <assert.h>
 
 #include <string>
@@ -22,9 +22,9 @@
 #include <GL/glext.h>
 
 #include "effect.h"
+#include "effect_chain.h"
 #include "util.h"
 #include "widgets.h"
-#include "texture_enum.h"
 
 unsigned char result[WIDTH * HEIGHT * 4];
 
@@ -33,282 +33,31 @@ float gamma_theta = 0.0f, gamma_rad = 0.0f, gamma_v = 0.5f;
 float gain_theta = 0.0f, gain_rad = 0.0f, gain_v = 0.25f;
 float saturation = 1.0f;
 
-float lift_r = 0.0f, lift_g = 0.0f, lift_b = 0.0f;
-float gamma_r = 1.0f, gamma_g = 1.0f, gamma_b = 1.0f;
-float gain_r = 1.0f, gain_g = 1.0f, gain_b = 1.0f;
-
-enum PixelFormat { FORMAT_RGB, FORMAT_RGBA };
-
-enum ColorSpace {
-	COLORSPACE_sRGB = 0,
-	COLORSPACE_REC_709 = 0,  // Same as sRGB.
-	COLORSPACE_REC_601_525 = 1,
-	COLORSPACE_REC_601_625 = 2,
-};
-
-enum GammaCurve {
-	GAMMA_LINEAR = 0,
-	GAMMA_sRGB = 1,
-	GAMMA_REC_601 = 2,
-	GAMMA_REC_709 = 2,  // Same as Rec. 601.
-};
-
-struct ImageFormat {
-	PixelFormat pixel_format;
-	ColorSpace color_space;
-	GammaCurve gamma_curve;
-};
-
-enum EffectId {
-	// Mostly for internal use.
-	GAMMA_CONVERSION = 0,
-	RGB_PRIMARIES_CONVERSION,
-
-	// Color.
-	LIFT_GAMMA_GAIN,
-};
-
-// Can alias on a float[3].
-struct RGBTriplet {
-	RGBTriplet(float r, float g, float b)
-		: r(r), g(g), b(b) {}
-
-	float r, g, b;
-};
-
-class GammaExpansionEffect : public Effect {
-public:
-	GammaExpansionEffect()
-		: source_curve(GAMMA_LINEAR)
-	{
-		register_int("source_curve", (int *)&source_curve);
-	}
-
-private:
-	GammaCurve source_curve;
-};
-
-class ColorSpaceConversionEffect : public Effect {
-public:
-	ColorSpaceConversionEffect()
-		: source_space(COLORSPACE_sRGB),
-		  destination_space(COLORSPACE_sRGB)
-	{
-		register_int("source_space", (int *)&source_space);
-		register_int("destination_space", (int *)&destination_space);
-	}
-
-private:
-	ColorSpace source_space, destination_space;
-};
-
-class ColorSpaceConversionEffect;
-
-class LiftGammaGainEffect : public Effect {
-public:
-	LiftGammaGainEffect()
-		: lift(0.0f, 0.0f, 0.0f),
-		  gamma(1.0f, 1.0f, 1.0f),
-		  gain(1.0f, 1.0f, 1.0f),
-		  saturation(1.0f)
-	{
-		register_vec3("lift", (float *)&lift);
-		register_vec3("gamma", (float *)&gamma);
-		register_vec3("gain", (float *)&gain);
-		register_float("saturation", &saturation);
-	}
-
-private:
-	RGBTriplet lift, gamma, gain;
-	float saturation;
-};
-
-class EffectChain {
-public:
-	EffectChain(unsigned width, unsigned height);
-	void add_input(const ImageFormat &format);
-
-	// The pointer is owned by EffectChain.
-	Effect *add_effect(EffectId effect);
-
-	void add_output(const ImageFormat &format);
-
-	void render(unsigned char *src, unsigned char *dst);
-
-private:
-	unsigned width, height;
-	ImageFormat input_format, output_format;
-	std::vector<Effect *> effects;
-
-	ColorSpace current_color_space;
-	GammaCurve current_gamma_curve;	
-};
-
-EffectChain::EffectChain(unsigned width, unsigned height)
-	: width(width), height(height) {}
-
-void EffectChain::add_input(const ImageFormat &format)
-{
-	input_format = format;
-	current_color_space = format.color_space;
-	current_gamma_curve = format.gamma_curve;
-}
-
-void EffectChain::add_output(const ImageFormat &format)
-{
-	output_format = format;
-}
+//float radius = 0.3f;
+// float inner_radius = 0.3f;
+float blur_radius = 20.0f;
+float blurred_mix_amount = 0.5f;
 	
-Effect *instantiate_effect(EffectId effect)
+void update_hsv(Effect *lift_gamma_gain_effect, Effect *saturation_effect)
 {
-	switch (effect) {
-	case GAMMA_CONVERSION:
-		return new GammaExpansionEffect();
-	case RGB_PRIMARIES_CONVERSION:
-		return new GammaExpansionEffect();
-	case LIFT_GAMMA_GAIN:
-		return new LiftGammaGainEffect();
-	}
-	assert(false);
-}
-
-Effect *EffectChain::add_effect(EffectId effect_id)
-{
-	Effect *effect = instantiate_effect(effect_id);
-
-	if (effect->needs_linear_light() && current_gamma_curve != GAMMA_LINEAR) {
-		GammaExpansionEffect *gamma_conversion = new GammaExpansionEffect();
-		gamma_conversion->set_int("source_curve", current_gamma_curve);
-		effects.push_back(gamma_conversion);
-		current_gamma_curve = GAMMA_LINEAR;
-	}
-
-	if (effect->needs_srgb_primaries() && current_color_space != COLORSPACE_sRGB) {
-		assert(current_gamma_curve == GAMMA_LINEAR);
-		ColorSpaceConversionEffect *colorspace_conversion = new ColorSpaceConversionEffect();
-		colorspace_conversion->set_int("source_space", current_color_space);
-		colorspace_conversion->set_int("destination_space", COLORSPACE_sRGB);
-		effects.push_back(colorspace_conversion);
-		current_color_space = COLORSPACE_sRGB;
-	}
-
-	effects.push_back(effect);
-	return effect;
-}
-
-GLhandleARB read_shader(const char* filename, GLenum type)
-{
-	static char buf[131072];
-	FILE *fp = fopen(filename, "r");
-	if (fp == NULL) {
-		perror(filename);
-		exit(1);
-	}
-
-	int len = fread(buf, 1, sizeof(buf), fp);
-	fclose(fp);
-
-	GLhandleARB obj = glCreateShaderObjectARB(type);
-	const GLchar* source[] = { buf };
-	const GLint length[] = { len };
-	glShaderSource(obj, 1, source, length);
-	glCompileShader(obj);
-
-	GLchar info_log[4096];
-	GLsizei log_length = sizeof(info_log) - 1;
-	glGetShaderInfoLog(obj, log_length, &log_length, info_log);
-	info_log[log_length] = 0; 
-	printf("shader compile log: %s\n", info_log);
-
-	GLint status;
-	glGetShaderiv(obj, GL_COMPILE_STATUS, &status);
-	if (status == GL_FALSE) {
-		exit(1);
-	}
+	RGBTriplet lift(0.0f, 0.0f, 0.0f);
+	RGBTriplet gamma(1.0f, 1.0f, 1.0f);
+	RGBTriplet gain(1.0f, 1.0f, 1.0f);
 
-	return obj;
-}
+	hsv2rgb(lift_theta, lift_rad, lift_v, &lift.r, &lift.g, &lift.b);
+	hsv2rgb(gamma_theta, gamma_rad, gamma_v * 2.0f, &gamma.r, &gamma.g, &gamma.b);
+	hsv2rgb(gain_theta, gain_rad, gain_v * 4.0f, &gain.r, &gain.g, &gain.b);
 
-void draw_picture_quad(GLint prog, int frame)
-{
-	glUseProgramObjectARB(prog);
-	check_error();
-
-	glActiveTexture(GL_TEXTURE0);
-	glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
-	glUniform1i(glGetUniformLocation(prog, "tex"), 0);
-
-	glActiveTexture(GL_TEXTURE1);
-	glBindTexture(GL_TEXTURE_1D, SRGB_LUT);
-	glUniform1i(glGetUniformLocation(prog, "srgb_tex"), 1);
-
-	glActiveTexture(GL_TEXTURE2);
-	glBindTexture(GL_TEXTURE_1D, SRGB_REVERSE_LUT);
-	glUniform1i(glGetUniformLocation(prog, "srgb_reverse_tex"), 2);
-
-	glUniform3f(glGetUniformLocation(prog, "lift"), lift_r, lift_g, lift_b);
-	//glUniform3f(glGetUniformLocation(prog, "gamma"), gamma_r, gamma_g, gamma_b);
-	glUniform3f(glGetUniformLocation(prog, "inv_gamma_22"),
-	            2.2f / gamma_r,
-	            2.2f / gamma_g,
-	            2.2f / gamma_b);
-	glUniform3f(glGetUniformLocation(prog, "gain_pow_inv_gamma"),
-	            pow(gain_r, 1.0f / gamma_r),
-	            pow(gain_g, 1.0f / gamma_g),
-	            pow(gain_b, 1.0f / gamma_b));
-	glUniform1f(glGetUniformLocation(prog, "saturation"), saturation);
-
-	glDisable(GL_BLEND);
-	check_error();
-	glDisable(GL_DEPTH_TEST);
-	check_error();
-	glDepthMask(GL_FALSE);
-	check_error();
-
-	glMatrixMode(GL_PROJECTION);
-	glLoadIdentity();
-	glOrtho(0.0, 1.0, 0.0, 1.0, 0.0, 1.0);
-
-	glMatrixMode(GL_MODELVIEW);
-	glLoadIdentity();
-
-	glClearColor(1.0f, 0.0f, 0.0f, 1.0f);
-//	glClear(GL_COLOR_BUFFER_BIT);
-	check_error();
-
-	glBegin(GL_QUADS);
-
-	glTexCoord2f(0.0f, 1.0f);
-	glVertex2f(0.0f, 0.0f);
-
-	glTexCoord2f(1.0f, 1.0f);
-	glVertex2f(1.0f, 0.0f);
-
-	glTexCoord2f(1.0f, 0.0f);
-	glVertex2f(1.0f, 1.0f);
-
-	glTexCoord2f(0.0f, 0.0f);
-	glVertex2f(0.0f, 1.0f);
-
-	glEnd();
-	check_error();
-}
-
-void update_hsv()
-{
-	hsv2rgb(lift_theta, lift_rad, lift_v, &lift_r, &lift_g, &lift_b);
-	hsv2rgb(gamma_theta, gamma_rad, gamma_v * 2.0f, &gamma_r, &gamma_g, &gamma_b);
-	hsv2rgb(gain_theta, gain_rad, gain_v * 4.0f, &gain_r, &gain_g, &gain_b);
+	bool ok = lift_gamma_gain_effect->set_vec3("lift", (float *)&lift);
+	ok = ok && lift_gamma_gain_effect->set_vec3("gamma", (float *)&gamma);
+	ok = ok && lift_gamma_gain_effect->set_vec3("gain", (float *)&gain);
+	assert(ok);
 
 	if (saturation < 0.0) {
 		saturation = 0.0;
 	}
-
-	printf("lift: %f %f %f\n", lift_r, lift_g, lift_b);
-	printf("gamma: %f %f %f\n", gamma_r, gamma_g, gamma_b);
-	printf("gain: %f %f %f\n", gain_r, gain_g, gain_b);
-	printf("saturation: %f\n", saturation);
-	printf("\n");
+	ok = saturation_effect->set_float("saturation", saturation);
+	assert(ok);
 }
 
 void mouse(int x, int y)
@@ -324,12 +73,20 @@ void mouse(int x, int y)
 		read_colorwheel(xf, yf - 0.4f, &gain_rad, &gain_theta, &gain_v);
 	} else if (yf >= 0.6f && yf < 0.62f && xf < 0.2f) {
 		saturation = (xf / 0.2f) * 4.0f;
+#if 0
+	} else if (yf >= 0.65f && yf < 0.67f && xf < 0.2f) {
+		radius = (xf / 0.2f);
+	} else if (yf >= 0.70f && yf < 0.72f && xf < 0.2f) {
+		inner_radius = (xf / 0.2f);
+#endif
+	} else if (yf >= 0.75f && yf < 0.77f && xf < 0.2f) {
+		blur_radius = (xf / 0.2f) * 100.0f;
+	} else if (yf >= 0.80f && yf < 0.82f && xf < 0.2f) {
+		blurred_mix_amount = (xf / 0.2f);
 	}
-
-	update_hsv();
 }
 
-void load_texture(const char *filename)
+unsigned char *load_image(const char *filename, unsigned *w, unsigned *h)
 {
 	SDL_Surface *img = IMG_Load(filename);
 	if (img == NULL) {
@@ -337,48 +94,34 @@ void load_texture(const char *filename)
 		exit(1);
 	}
 
-	// Convert to RGB.
-	SDL_PixelFormat *fmt = img->format;
-	SDL_LockSurface(img);
-	unsigned char *src_pixels = (unsigned char *)img->pixels;
-	unsigned char *dst_pixels = (unsigned char *)malloc(img->w * img->h * 3);
-	for (unsigned i = 0; i < img->w * img->h; ++i) {
-		unsigned char r, g, b;
-		unsigned int temp;
-		unsigned int pixel = *(unsigned int *)(src_pixels + i * fmt->BytesPerPixel);
-
-		temp = pixel & fmt->Rmask;
-		temp = temp >> fmt->Rshift;
-		temp = temp << fmt->Rloss;
-		r = temp;
-
-		temp = pixel & fmt->Gmask;
-		temp = temp >> fmt->Gshift;
-		temp = temp << fmt->Gloss;
-		g = temp;
-
-		temp = pixel & fmt->Bmask;
-		temp = temp >> fmt->Bshift;
-		temp = temp << fmt->Bloss;
-		b = temp;
-
-		dst_pixels[i * 3 + 0] = r;
-		dst_pixels[i * 3 + 1] = g;
-		dst_pixels[i * 3 + 2] = b;
-	}
-	SDL_UnlockSurface(img);
+	SDL_PixelFormat rgba_fmt;
+	rgba_fmt.palette = NULL;
+	rgba_fmt.BitsPerPixel = 32;
+	rgba_fmt.BytesPerPixel = 8;
+	rgba_fmt.Rloss = rgba_fmt.Gloss = rgba_fmt.Bloss = rgba_fmt.Aloss = 0;
+
+	// NOTE: Assumes little endian.
+	rgba_fmt.Rmask = 0x00ff0000;
+	rgba_fmt.Gmask = 0x0000ff00;
+	rgba_fmt.Bmask = 0x000000ff;
+	rgba_fmt.Amask = 0xff000000;
+
+	rgba_fmt.Rshift = 16;
+	rgba_fmt.Gshift = 8;
+	rgba_fmt.Bshift = 0;
+	rgba_fmt.Ashift = 24;
+	
+	rgba_fmt.colorkey = 0;
+	rgba_fmt.alpha = 255;
+
+	SDL_Surface *converted = SDL_ConvertSurface(img, &rgba_fmt, SDL_SWSURFACE);
+
+	*w = img->w;
+	*h = img->h;
 
-#if 1
-	// we will convert to sRGB in the shader
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, img->w, img->h, 0, GL_RGB, GL_UNSIGNED_BYTE, dst_pixels);
-	check_error();
-#else
-	// implicit sRGB conversion in hardware
-	glTexImage2D(GL_TEXTURE_2D, 0, GL_SRGB8, img->w, img->h, 0, GL_RGB, GL_UNSIGNED_BYTE, dst_pixels);
-	check_error();
-#endif
-	free(dst_pixels);
 	SDL_FreeSurface(img);
+
+	return (unsigned char *)converted->pixels;
 }
 
 void write_ppm(const char *filename, unsigned char *screenbuf)
@@ -411,57 +154,26 @@ int main(int argc, char **argv)
 	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 	glPixelStorei(GL_PACK_ALIGNMENT, 1);
 
-	glBindTexture(GL_TEXTURE_2D, SOURCE_IMAGE);
-	check_error();
-	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-	check_error();
+	unsigned img_w, img_h;
+	unsigned char *src_img = load_image("blg_wheels_woman_1.jpg", &img_w, &img_h);
 
-	load_texture("blg_wheels_woman_1.jpg");
-	//glGenerateMipmap(GL_TEXTURE_2D);
-	//glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_BASE_LEVEL, 4);
-	//check_error();
+	EffectChain chain(WIDTH, HEIGHT);
 
-	//load_texture("maserati_gts_wallpaper_1280x720_01.jpg");
-	//load_texture("90630d1295075297-console-games-wallpapers-wallpaper_need_for_speed_prostreet_09_1920x1080.jpg");
-	//load_texture("glacier-lake-1280-720-4087.jpg");
+	ImageFormat inout_format;
+	inout_format.pixel_format = FORMAT_BGRA;
+	inout_format.color_space = COLORSPACE_sRGB;
+	inout_format.gamma_curve = GAMMA_sRGB;
 
-#if 0
-	// sRGB reverse LUT
-	glBindTexture(GL_TEXTURE_1D, SRGB_REVERSE_LUT);
-	check_error();
-	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-	check_error();
-	float srgb_reverse_tex[4096];
-	for (unsigned i = 0; i < 4096; ++i) {
-		float x = i / 4095.0;
-		if (x < 0.0031308f) {
-			srgb_reverse_tex[i] = 12.92f * x;
-		} else {
-			srgb_reverse_tex[i] = 1.055f * pow(x, 1.0f / 2.4f) - 0.055f;
-		}
-	}
-	glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE16F_ARB, 4096, 0, GL_LUMINANCE, GL_FLOAT, srgb_reverse_tex);
-	check_error();
-
-	// sRGB LUT
-	glBindTexture(GL_TEXTURE_1D, SRGB_LUT);
-	check_error();
-	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-	glTexParameteri(GL_TEXTURE_1D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-	check_error();
-	float srgb_tex[256];
-	for (unsigned i = 0; i < 256; ++i) {
-		float x = i / 255.0;
-		if (x < 0.04045f) {
-			srgb_tex[i] = x * (1.0f / 12.92f);
-		} else {
-			srgb_tex[i] = pow((x + 0.055) * (1.0 / 1.055f), 2.4);
-		}
-	}
-	glTexImage1D(GL_TEXTURE_1D, 0, GL_LUMINANCE16F_ARB, 256, 0, GL_LUMINANCE, GL_FLOAT, srgb_tex);
-	check_error();
-#endif
+	chain.add_input(inout_format);
+	Effect *lift_gamma_gain_effect = chain.add_effect(EFFECT_LIFT_GAMMA_GAIN);
+	Effect *saturation_effect = chain.add_effect(EFFECT_SATURATION);
+	Effect *diffusion_effect = chain.add_effect(EFFECT_DIFFUSION);
+	//Effect *vignette_effect = chain.add_effect(EFFECT_VIGNETTE);
+	//Effect *sandbox_effect = chain.add_effect(EFFECT_SANDBOX);
+	//sandbox_effect->set_float("parm", 42.0f);
+	//chain.add_effect(EFFECT_MIRROR);
+	chain.add_output(inout_format);
+	chain.finalize();
 
 	// generate a PDO to hold the data we read back with glReadPixels()
 	// (Intel/DRI goes into a slow path if we don't read to PDO)
@@ -469,28 +181,15 @@ int main(int argc, char **argv)
 	glBufferData(GL_PIXEL_PACK_BUFFER_ARB, WIDTH * HEIGHT * 4, NULL, GL_STREAM_READ);
 
 	make_hsv_wheel_texture();
-	update_hsv();
-
-	int prog = glCreateProgram();
-	GLhandleARB vs_obj = read_shader("vs.glsl", GL_VERTEX_SHADER);
-	GLhandleARB fs_obj = read_shader("fs.glsl", GL_FRAGMENT_SHADER);
-	glAttachObjectARB(prog, vs_obj);
-	check_error();
-	glAttachObjectARB(prog, fs_obj);
-	check_error();
-	glLinkProgram(prog);
-	check_error();
-
-	GLchar info_log[4096];
-	GLsizei log_length = sizeof(info_log) - 1;
-	log_length = sizeof(info_log) - 1;
-	glGetProgramInfoLog(prog, log_length, &log_length, info_log);
-	info_log[log_length] = 0; 
-	printf("link: %s\n", info_log);
 
-	struct timespec start, now;
 	int frame = 0, screenshot = 0;
+#if _POSIX_C_SOURCE >= 199309L
+	struct timespec start, now;
 	clock_gettime(CLOCK_MONOTONIC, &start);
+#else
+	struct timeval start, now;
+	gettimeofday(&start, NULL);
+#endif
 
 	while (!quit) {
 		SDL_Event event;
@@ -510,19 +209,40 @@ int main(int argc, char **argv)
 
 		++frame;
 
-		draw_picture_quad(prog, frame);
+		update_hsv(lift_gamma_gain_effect, saturation_effect);
+		//vignette_effect->set_float("radius", radius);
+		//vignette_effect->set_float("inner_radius", inner_radius);
+		//vignette_effect->set_vec2("center", (float[]){ 0.7f, 0.5f });
+
+		diffusion_effect->set_float("radius", blur_radius);
+		diffusion_effect->set_float("blurred_mix_amount", blurred_mix_amount);
+
+		chain.render_to_screen(src_img);
 		
+		glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 1);
+		check_error();
 		glReadPixels(0, 0, WIDTH, HEIGHT, GL_BGRA, GL_UNSIGNED_INT_8_8_8_8_REV, BUFFER_OFFSET(0));
 		check_error();
+		glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 0);
+		check_error();
 
+		glLoadIdentity();
 		draw_hsv_wheel(0.0f, lift_rad, lift_theta, lift_v);
 		draw_hsv_wheel(0.2f, gamma_rad, gamma_theta, gamma_v);
 		draw_hsv_wheel(0.4f, gain_rad, gain_theta, gain_v);
-		draw_saturation_bar(0.6f, saturation);
+		draw_saturation_bar(0.6f, saturation / 4.0f);
+#if 0
+		draw_saturation_bar(0.65f, radius);
+		draw_saturation_bar(0.70f, inner_radius);
+#endif
+		draw_saturation_bar(0.75f, blur_radius / 100.0f);
+		draw_saturation_bar(0.80f, blurred_mix_amount);
 
 		SDL_GL_SwapBuffers();
 		check_error();
 
+		glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 1);
+		check_error();
 		unsigned char *screenbuf = (unsigned char *)glMapBuffer(GL_PIXEL_PACK_BUFFER_ARB, GL_READ_ONLY);
 		check_error();
 		if (screenshot) {
@@ -534,11 +254,19 @@ int main(int argc, char **argv)
 		}
 		glUnmapBuffer(GL_PIXEL_PACK_BUFFER_ARB);
 		check_error();
+		glBindBuffer(GL_PIXEL_PACK_BUFFER_ARB, 0);
+		check_error();
 
 #if 1
+#if _POSIX_C_SOURCE >= 199309L
 		clock_gettime(CLOCK_MONOTONIC, &now);
 		double elapsed = now.tv_sec - start.tv_sec +
 			1e-9 * (now.tv_nsec - start.tv_nsec);
+#else
+		gettimeofday(&now, NULL);
+		double elapsed = now.tv_sec - start.tv_sec +
+			1e-6 * (now.tv_usec - start.tv_usec);
+#endif
 		printf("%d frames in %.3f seconds = %.1f fps (%.1f ms/frame)\n",
 			frame, elapsed, frame / elapsed,
 			1e3 * elapsed / frame);