Initial import

4 files changed, 636 insertions, 0 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
new file mode 100644
index 0000000..19b90d5
--- /dev/null
+++ b/src/Makefile.am
@@ -0,0 +1,27 @@
+# Copyright © 2012 Ian D. Romanick
+# All Rights Reserved.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a
+# copy of this software and associated documentation files (the "Software"),
+# to deal in the Software without restriction, including without limitation
+# on the rights to use, copy, modify, merge, publish, distribute, sub
+# license, and/or sell copies of the Software, and to permit persons to whom
+# the Software is furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice (including the next
+# paragraph) shall be included in all copies or substantial portions of the
+# Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.  IN NO EVENT SHALL
+# AUTHORS, COPYRIGHT HOLDERS, AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
+# DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+# OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
+# USE OR OTHER DEALINGS IN THE SOFTWARE.
+
+bin_PROGRAMS = complex-plane
+complex_plane_SOURCES = main.cpp shader.cpp
+
+AM_CXXFLAGS= $(GLU3_CFLAGS)
+complex_plane_LDADD = $(GLU3_LIBS)
diff --git a/src/main.cpp b/src/main.cpp
new file mode 100644
index 0000000..083427c
--- /dev/null
+++ b/src/main.cpp
@@ -0,0 +1,499 @@
+/*
+ * Copyright © 2012 Ian D. Romanick
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+#include <math.h>
+#include <GL/glew.h>
+#include <glu3.h>
+#include <SDL.h>
+#include <assert.h>
+#include "shader.h"
+
+#define NUM_POINTS 57
+
+static SDL_Surface *my_surf = NULL;
+
+static bool anim = true;
+static bool done = false;
+static int shift_status = 0;
+
+static float angle_offset = 0.0f;
+
+static GLuint buf =  0;
+
+class complex_points_program : public shader_program {
+public:
+	complex_points_program(GLuint vs, GLuint fs)
+		: shader_program(vs, fs, 0)
+	{
+		/* empty */
+	}
+
+	void get_uniform_locations()
+	{
+		this->angle_uniform =
+			glGetUniformLocation(this->program, "rotation_angle");
+		this->matrix_uniform =
+			glGetUniformLocation(this->program, "m");
+	}
+
+	GLint angle_uniform;
+	GLint matrix_uniform;
+};
+
+static complex_points_program *explicit_rotation = 0;
+static complex_points_program *angle_addition = 0;
+static complex_points_program *matrix_rotation = 0;
+
+static GLuint timer_queries[3] = { 0, 0, 0 };
+
+#define BUFFER_OFFSET(i) ((char *)0 + (i))
+
+#define CHECK_GL_ERROR(e) \
+	do { \
+		e = glGetError(); \
+		if (e != 0) { \
+			printf("%s:%u: GL error = 0x%04x\n", __func__, \
+			       __LINE__, e); \
+		} \
+	} while (0)
+
+
+static void
+Redisplay(void)
+{
+	const float m[4] = {
+		1.0, 0.0,
+		0.0, 1.0
+	};
+
+
+	/* Set the viewport to the whole window and clear the screen.
+	 */
+	glViewport(0, 0, my_surf->w, my_surf->h);
+	glClear(GL_COLOR_BUFFER_BIT);
+
+
+	/* Reset the viewport ot the lower left quadrant and draw using the
+	 * "explicit rotation" shader.  This shader uses the vertex data
+	 * stored as (real, imaginary) pairs.
+	 */
+	glViewport(0, 0, my_surf->w / 2, my_surf->h / 2);
+
+	glUseProgram(explicit_rotation->program);
+	glUniform1f(explicit_rotation->angle_uniform, angle_offset);
+	glUniformMatrix2fv(explicit_rotation->matrix_uniform, 1, false, m);
+
+	if (timer_queries[0])
+		glBeginQuery(GL_TIME_ELAPSED, timer_queries[0]);
+
+	glDrawArrays(GL_POINTS, 0, NUM_POINTS);
+
+	if (timer_queries[0])
+		glEndQuery(GL_TIME_ELAPSED);
+
+
+	/* Reset the viewport to the upper left quadrant and draw using the
+	 * "angle addition" shader.  This shader uses the vertex data stored
+	 * as (modulus, angle) pairs.
+	 */
+	glViewport(0, my_surf->h / 2, my_surf->w / 2, my_surf->h / 2);
+
+	glUseProgram(angle_addition->program);
+	glUniform1f(angle_addition->angle_uniform, angle_offset);
+	glUniformMatrix2fv(angle_addition->matrix_uniform, 1, false, m);
+
+	if (timer_queries[1])
+		glBeginQuery(GL_TIME_ELAPSED, timer_queries[1]);
+
+	glDrawArrays(GL_POINTS, NUM_POINTS, NUM_POINTS);
+
+	if (timer_queries[1])
+		glEndQuery(GL_TIME_ELAPSED);
+
+	/* Reset the viewport to the upper right quadrant and draw using the
+	 * "matrix rotation" shader.  This shader uses the vertex data stored
+	 * as (real, imaginary) pairs.
+	 */
+	glViewport(my_surf->w / 2, my_surf->h / 2,
+		   my_surf->w / 2, my_surf->h / 2);
+
+	glUseProgram(matrix_rotation->program);
+	glUniform1f(matrix_rotation->angle_uniform, angle_offset);
+	glUniformMatrix2fv(matrix_rotation->matrix_uniform, 1, false, m);
+
+	if (timer_queries[2])
+		glBeginQuery(GL_TIME_ELAPSED, timer_queries[2]);
+
+	glDrawArrays(GL_POINTS, 0, NUM_POINTS);
+
+	if (timer_queries[2])
+		glEndQuery(GL_TIME_ELAPSED);
+
+	SDL_GL_SwapBuffers();
+
+	assert((timer_queries[0] == 0) == (timer_queries[1] == 0));
+	if (timer_queries[0]) {
+		static GLuint64 totals[3] = { 0, 0, 0 };
+		static unsigned count = 0;
+		GLuint64 result[3] = { 0, 0, 0 };
+
+		for (unsigned i = 0; i < 3; i++) {
+			glGetQueryObjectui64vEXT(timer_queries[i],
+						 GL_QUERY_RESULT,
+						 &result[i]);
+			totals[i] += result[i];
+		}
+
+		count++;
+		if (count > 100) {
+			printf("Timings: %lu, %lu, %lu\n",
+			       totals[0] / 100,
+			       totals[1] / 100,
+			       totals[2] / 100);
+
+			memset(totals, 0, sizeof(totals));
+			count = 0;
+		}
+	}
+}
+
+
+static void Idle(void)
+{
+	static Uint32 last_t = ~0;
+	Uint32 t = SDL_GetTicks();
+
+
+	if (last_t != (Uint32)~0) {
+		float dt = (float) (t - last_t) / 1000.0f;
+
+		if (anim) {
+			angle_offset += M_PI * dt;
+		}
+	}
+
+	last_t = t;
+}
+
+
+
+
+static GLuint
+compile_shader_from_file(GLenum target, const char *filename)
+{
+	static const char *const paths_to_try[] = {
+		"",
+		"data/",
+		"../data/",
+		0
+	};
+
+	GLuint shader;
+	char *log = NULL;
+	const char *code;
+
+	const size_t name_len = strlen(filename);
+	for (unsigned i = 0; paths_to_try[i] != 0; i++) {
+		const size_t path_len = strlen(paths_to_try[i]);
+		char *name_with_path = new char [path_len + name_len + 1];
+
+		memcpy(name_with_path, paths_to_try[i], path_len);
+		memcpy(&name_with_path[path_len], filename, name_len);
+		name_with_path[path_len + name_len] = '\0';
+	
+		code = gluLoadTextFile(name_with_path);
+		delete [] name_with_path;
+
+		if (code != NULL)
+			break;
+	}
+
+	if (code == NULL) {
+		fprintf(stderr, "Unable to load shader code for %s.\n",
+			filename);
+		exit(1);
+	}
+
+	shader = gluCompileShader(target, code, &log);
+	if (log != NULL) {
+		printf("Shader compile log for %s:\n%s\n", filename, log);
+		gluReleaseInfoLog(log);
+		log = NULL;
+	}
+
+	if (shader == 0) {
+		fprintf(stderr, "Failed to compile %s.\n", filename);
+		exit(1);
+	}
+
+	gluUnloadTextFile(code);
+
+	return shader;
+}
+
+
+static complex_points_program *
+create_program(GLuint vs, GLuint fs, const char *name)
+{
+	complex_points_program *p = new complex_points_program(vs, fs);
+
+	const bool linked = p->link();
+	if (p->log != NULL)
+		printf("%s link log:\n%s\n", name, p->log);
+
+	if (!linked) {
+		fprintf(stderr, "Failed to link %s.\n", name);
+		exit(1);
+	}
+
+	p->get_uniform_locations();
+	return p;
+}
+
+/* Load, compile, link, etc. the vertex and fragment programs.
+ */
+static void
+build_all_shaders(void)
+{
+	GLuint vs[3];
+	GLuint fs;
+
+	/* If there are dangling instances of these program hanging around,
+	 * clean them up.
+	 */
+	if (explicit_rotation)
+		delete explicit_rotation;
+
+	if (angle_addition)
+		delete angle_addition;
+
+	if (matrix_rotation)
+		delete matrix_rotation;
+
+
+	/* Compile all of the shaders
+	 */
+	vs[0] = compile_shader_from_file(GL_VERTEX_SHADER,
+					 "explicit_rotation.vert");
+	vs[1] = compile_shader_from_file(GL_VERTEX_SHADER,
+					 "angle_addition.vert");
+	vs[2] = compile_shader_from_file(GL_VERTEX_SHADER,
+					 "matrix_rotation.vert");
+
+	fs = compile_shader_from_file(GL_FRAGMENT_SHADER,
+				      "ellipse.frag");
+
+	/* Create all of the programs that use the previously created shaders.
+	 */
+	explicit_rotation = create_program(vs[0], fs, "explicit rotation");
+	angle_addition = create_program(vs[1], fs, "angle addition");
+	matrix_rotation = create_program(vs[2], fs, "matrix rotation");
+
+	/* The individual shaders have been attached to the programs, so they
+	 * can safely be deleted.
+	 */
+	glDeleteShader(vs[0]);
+	glDeleteShader(vs[1]);
+	glDeleteShader(vs[2]);
+	glDeleteShader(fs);
+}
+
+
+static void
+Init(void)
+{
+	glewInit();
+
+	if (!GLEW_VERSION_2_0) {
+		printf ("Sorry, this demo requires OpenGL 2.0 or later.\n");
+		exit(1);
+	}
+
+	if (GLEW_EXT_timer_query || GLEW_ARB_timer_query)
+		glGenQueries(3, timer_queries);
+
+	gluInitializeCompiler();
+	
+	explicit_rotation = 0;
+	angle_addition = 0;
+	matrix_rotation = 0;
+
+	build_all_shaders();
+
+	float data[2 * (2 * NUM_POINTS)];
+
+	for (unsigned i = 0; i < NUM_POINTS; i++) {
+		const float angle = float(i) * M_PI * 2.0f / float(NUM_POINTS);
+		const float r = cos(5.0f * angle) * 0.4f + 0.5f;
+
+		data[(i +          0) * 2 + 0] = r * cos(angle);
+		data[(i +          0) * 2 + 1] = r * sin(angle);
+		data[(i + NUM_POINTS) * 2 + 0] = r;
+		data[(i + NUM_POINTS) * 2 + 1] = angle;
+	}
+
+	glGenBuffers(1, &buf);
+	glBindBuffer(GL_ARRAY_BUFFER, buf);
+	glBufferData(GL_ARRAY_BUFFER, sizeof(data), data, GL_STATIC_DRAW);
+
+	glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 2 * sizeof(GLfloat),
+			      BUFFER_OFFSET(0));
+	glEnableVertexAttribArray(0);
+
+	glEnable(GL_VERTEX_PROGRAM_POINT_SIZE);
+
+
+	printf("GL_RENDERER = %s\n", (const char *) glGetString(GL_RENDERER));
+	printf("Keyboard input:\n"
+	       "    a: Toggle animation of object.\n"
+	       "    c: Re-load and compile shader program code.\n"
+	       "  ESC: Exit program.\n");
+}
+
+
+static void
+Reshape(int w, int h)
+{
+	my_surf = SDL_SetVideoMode(w, h, 0, SDL_OPENGL | SDL_RESIZABLE);
+	if (my_surf == NULL) {
+		exit(1);
+	}
+
+	glViewport(0, 0, my_surf->w, my_surf->h);
+	Init();
+}
+
+
+static void
+Key(SDLKey sym)
+{
+	switch (sym) {
+	case SDLK_ESCAPE:
+		done = true;
+		break;
+
+	case ' ':
+	case 'a':
+		anim = !anim;
+		break;
+
+	case 'c':
+		printf("Reloading and compiling program code...\n");
+		build_all_shaders();
+		break;
+
+	default:
+		break;
+	}
+}
+
+
+/**
+ * Push an event each time the timer callback fires.
+ */
+Uint32
+timer_callback(Uint32 interval, void *not_used)
+{
+	SDL_Event e;
+
+	(void) not_used;
+
+	e.type = SDL_USEREVENT;
+	e.user.code = 0;
+	e.user.data1 = NULL;
+	e.user.data2 = NULL;
+	SDL_PushEvent(& e);
+
+	return interval;
+}
+
+
+int
+main(int argc, char **argv)
+{
+	(void) argc;
+	(void) argv;
+
+	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER) < 0) {
+		exit(1);
+	}
+
+	atexit(SDL_Quit);
+
+	Reshape(800, 600);
+
+	SDL_TimerID timer_id = SDL_AddTimer(10, timer_callback, NULL);
+
+	while (!done) {
+		SDL_Event event;
+
+		SDL_WaitEvent(&event);
+		do {
+			switch (event.type) {
+			case SDL_VIDEORESIZE:
+				Reshape(event.resize.w, event.resize.h);
+				break;
+
+			case SDL_QUIT:
+				done = true;
+				break;
+
+			case SDL_KEYDOWN:
+				if ((event.key.keysym.sym == SDLK_RSHIFT)
+				    || (event.key.keysym.sym == SDLK_LSHIFT)) {
+					shift_status++;
+				} else {
+					Key(event.key.keysym.sym);
+				}
+				break;
+
+			case SDL_KEYUP:
+				if ((event.key.keysym.sym == SDLK_RSHIFT)
+				    || (event.key.keysym.sym == SDLK_LSHIFT)) {
+					shift_status--;
+				}
+
+				/* By clamping the shift status value to 0 we
+				 * prevent some bugs when the program is
+				 * started with one or both of the shift keys
+				 * held down.
+				 */
+				if (shift_status < 0) {
+					shift_status = 0;
+				}
+				break;
+
+			default:
+				break;
+			}
+		} while (SDL_PollEvent(&event));
+
+
+		Idle();
+		Redisplay();
+	}
+
+	SDL_RemoveTimer(timer_id);
+
+	SDL_Quit();
+	return 0;
+}
diff --git a/src/shader.cpp b/src/shader.cpp
new file mode 100644
index 0000000..8456362
--- /dev/null
+++ b/src/shader.cpp
@@ -0,0 +1,69 @@
+/*
+ * Copyright © 2012 Ian D. Romanick
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+#include <stdarg.h>
+#include <GL/glew.h>
+#include <glu3.h>
+#include "shader.h"
+
+void shader_program::init()
+{
+	this->program = glCreateProgram();
+	this->log = 0;
+}
+
+shader_program::shader_program()
+{
+	init();
+}
+
+shader_program::shader_program(GLint shader, ...)
+{
+	va_list ap;
+	GLint sh;
+
+	init();
+
+	glAttachShader(this->program, shader);
+
+	va_start(ap, shader);
+	while ((sh = va_arg(ap, GLint)) != 0) {
+		glAttachShader(this->program, sh);
+	}
+	va_end(ap);
+}
+
+shader_program::~shader_program()
+{
+	glDeleteProgram(this->program);
+	this->program = 0;
+
+	if (this->log) {
+		gluReleaseInfoLog(this->log);
+		this->log = 0;
+	}
+}
+
+bool shader_program::link()
+{
+	return gluLinkProgram(this->program, &this->log);
+}
diff --git a/src/shader.h b/src/shader.h
new file mode 100644
index 0000000..5e49dc3
--- /dev/null
+++ b/src/shader.h
@@ -0,0 +1,41 @@
+/*
+ * Copyright © 2012 Ian D. Romanick
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+#ifndef SHADER_PROGRAM_H
+#define SHADER_PROGRAM_H
+
+class shader_program {
+public:
+	shader_program();
+	shader_program(GLint shader, ...);
+	~shader_program();
+
+	bool link();
+
+	GLint program;
+	char *log;
+
+private:
+	void init();
+};
+
+#endif /* SHADER_PROGRAM_H */