gtk/tests/gtkgears.c
2014-10-14 14:33:08 +02:00

440 lines
13 KiB
C

/* The rendering code in here is taken from glxgears, which has the
* following copyright notice:
*
* Copyright (C) 1999-2001 Brian Paul 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
* 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 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
* BRIAN PAUL 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 <epoxy/gl.h>
#include "gtkgears.h"
typedef struct {
GLfloat view_rot[GTK_GEARS_N_AXIS];
GLint gear1, gear2, gear3;
GLfloat angle;
gint64 first_frame_time;
guint tick;
GtkLabel *fps_label;
} GtkGearsPrivate;
G_DEFINE_TYPE_WITH_PRIVATE (GtkGears, gtk_gears, GTK_TYPE_GL_AREA);
static gboolean gtk_gears_render (GtkGLArea *area,
GdkGLContext *context);
static void gtk_gears_size_allocate (GtkWidget *widget,
GtkAllocation *allocation);
static void gtk_gears_realize (GtkWidget *widget);
static gboolean gtk_gears_tick (GtkWidget *widget,
GdkFrameClock *frame_clock,
gpointer user_data);
GtkWidget *
gtk_gears_new (void)
{
GtkWidget *gears;
gears = g_object_new (gtk_gears_get_type (),
"has-depth-buffer", TRUE,
NULL);
return gears;
}
static void
gtk_gears_init (GtkGears *gears)
{
GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
priv->view_rot[GTK_GEARS_X_AXIS] = 20.0;
priv->view_rot[GTK_GEARS_Y_AXIS] = 30.0;
priv->view_rot[GTK_GEARS_Z_AXIS] = 20.0;
priv->tick = gtk_widget_add_tick_callback (GTK_WIDGET (gears), gtk_gears_tick, gears, NULL);
}
static void
gtk_gears_finalize (GObject *obj)
{
GtkGears *gears = GTK_GEARS (obj);
GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
gtk_widget_remove_tick_callback (GTK_WIDGET (gears), priv->tick);
g_clear_object (&priv->fps_label);
G_OBJECT_CLASS (gtk_gears_parent_class)->finalize (obj);
}
static void
gtk_gears_class_init (GtkGearsClass *klass)
{
GTK_GL_AREA_CLASS (klass)->render = gtk_gears_render;
GTK_WIDGET_CLASS (klass)->realize = gtk_gears_realize;
GTK_WIDGET_CLASS (klass)->size_allocate = gtk_gears_size_allocate;
G_OBJECT_CLASS (klass)->finalize = gtk_gears_finalize;
}
/*
*
* Draw a gear wheel. You'll probably want to call this function when
* building a display list since we do a lot of trig here.
*
* Input: inner_radius - radius of hole at center
* outer_radius - radius at center of teeth
* width - width of gear
* teeth - number of teeth
* tooth_depth - depth of tooth
*/
static void
gear(GLfloat inner_radius, GLfloat outer_radius, GLfloat width,
GLint teeth, GLfloat tooth_depth)
{
GLint i;
GLfloat r0, r1, r2;
GLfloat angle, da;
GLfloat u, v, len;
r0 = inner_radius;
r1 = outer_radius - tooth_depth / 2.0;
r2 = outer_radius + tooth_depth / 2.0;
da = 2.0 * G_PI / teeth / 4.0;
glShadeModel(GL_FLAT);
glNormal3f(0.0, 0.0, 1.0);
/* draw front face */
glBegin(GL_QUAD_STRIP);
for (i = 0; i <= teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
if (i < teeth) {
glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
width * 0.5);
}
}
glEnd();
/* draw front sides of teeth */
glBegin(GL_QUADS);
da = 2.0 * M_PI / teeth / 4.0;
for (i = 0; i < teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
width * 0.5);
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
width * 0.5);
}
glEnd();
glNormal3f(0.0, 0.0, -1.0);
/* draw back face */
glBegin(GL_QUAD_STRIP);
for (i = 0; i <= teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
if (i < teeth) {
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
-width * 0.5);
glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
}
}
glEnd();
/* draw back sides of teeth */
glBegin(GL_QUADS);
da = 2.0 * M_PI / teeth / 4.0;
for (i = 0; i < teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
-width * 0.5);
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
-width * 0.5);
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
}
glEnd();
/* draw outward faces of teeth */
glBegin(GL_QUAD_STRIP);
for (i = 0; i < teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glVertex3f(r1 * cos(angle), r1 * sin(angle), width * 0.5);
glVertex3f(r1 * cos(angle), r1 * sin(angle), -width * 0.5);
u = r2 * cos(angle + da) - r1 * cos(angle);
v = r2 * sin(angle + da) - r1 * sin(angle);
len = sqrt(u * u + v * v);
u /= len;
v /= len;
glNormal3f(v, -u, 0.0);
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), width * 0.5);
glVertex3f(r2 * cos(angle + da), r2 * sin(angle + da), -width * 0.5);
glNormal3f(cos(angle), sin(angle), 0.0);
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
width * 0.5);
glVertex3f(r2 * cos(angle + 2 * da), r2 * sin(angle + 2 * da),
-width * 0.5);
u = r1 * cos(angle + 3 * da) - r2 * cos(angle + 2 * da);
v = r1 * sin(angle + 3 * da) - r2 * sin(angle + 2 * da);
glNormal3f(v, -u, 0.0);
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
width * 0.5);
glVertex3f(r1 * cos(angle + 3 * da), r1 * sin(angle + 3 * da),
-width * 0.5);
glNormal3f(cos(angle), sin(angle), 0.0);
}
glVertex3f(r1 * cos(0), r1 * sin(0), width * 0.5);
glVertex3f(r1 * cos(0), r1 * sin(0), -width * 0.5);
glEnd();
glShadeModel(GL_SMOOTH);
/* draw inside radius cylinder */
glBegin(GL_QUAD_STRIP);
for (i = 0; i <= teeth; i++) {
angle = i * 2.0 * M_PI / teeth;
glNormal3f(-cos(angle), -sin(angle), 0.0);
glVertex3f(r0 * cos(angle), r0 * sin(angle), -width * 0.5);
glVertex3f(r0 * cos(angle), r0 * sin(angle), width * 0.5);
}
glEnd();
}
/* new window size or exposure */
static void
reshape(int width, int height)
{
GLfloat h = (GLfloat) height / (GLfloat) width;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -40.0);
}
static gboolean
gtk_gears_render (GtkGLArea *area,
GdkGLContext *context)
{
GtkGearsPrivate *priv = gtk_gears_get_instance_private (GTK_GEARS (area));
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glRotatef(priv->view_rot[GTK_GEARS_X_AXIS], 1.0, 0.0, 0.0);
glRotatef(priv->view_rot[GTK_GEARS_Y_AXIS], 0.0, 1.0, 0.0);
glRotatef(priv->view_rot[GTK_GEARS_Z_AXIS], 0.0, 0.0, 1.0);
glPushMatrix();
glTranslatef(-3.0, -2.0, 0.0);
glRotatef(priv->angle, 0.0, 0.0, 1.0);
glCallList(priv->gear1);
glPopMatrix();
glPushMatrix();
glTranslatef(3.1, -2.0, 0.0);
glRotatef(-2.0 * priv->angle - 9.0, 0.0, 0.0, 1.0);
glCallList(priv->gear2);
glPopMatrix();
glPushMatrix();
glTranslatef(-3.1, 4.2, 0.0);
glRotatef(-2.0 * priv->angle - 25.0, 0.0, 0.0, 1.0);
glCallList(priv->gear3);
glPopMatrix();
glPopMatrix();
return TRUE;
}
static void
gtk_gears_size_allocate (GtkWidget *widget,
GtkAllocation *allocation)
{
GtkGLArea *glarea = GTK_GL_AREA (widget);
GTK_WIDGET_CLASS (gtk_gears_parent_class)->size_allocate (widget, allocation);
if (gtk_widget_get_realized (widget))
{
gtk_gl_area_make_current (glarea);
reshape (allocation->width, allocation->height);
}
}
static void
gtk_gears_realize (GtkWidget *widget)
{
GtkGLArea *glarea = GTK_GL_AREA (widget);
GtkGears *gears = GTK_GEARS(widget);
GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
GtkAllocation allocation;
static GLfloat pos[4] = { 5.0, 5.0, 10.0, 0.0 };
static GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
static GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 };
static GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };
GTK_WIDGET_CLASS (gtk_gears_parent_class)->realize (widget);
gtk_gl_area_make_current (glarea);
glLightfv(GL_LIGHT0, GL_POSITION, pos);
glEnable(GL_CULL_FACE);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glEnable(GL_DEPTH_TEST);
/* make the gears */
priv->gear1 = glGenLists(1);
glNewList(priv->gear1, GL_COMPILE);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, red);
gear(1.0, 4.0, 1.0, 20, 0.7);
glEndList();
priv->gear2 = glGenLists(1);
glNewList(priv->gear2, GL_COMPILE);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, green);
gear(0.5, 2.0, 2.0, 10, 0.7);
glEndList();
priv->gear3 = glGenLists(1);
glNewList(priv->gear3, GL_COMPILE);
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, blue);
gear(1.3, 2.0, 0.5, 10, 0.7);
glEndList();
glEnable(GL_NORMALIZE);
gtk_widget_get_allocation (widget, &allocation);
reshape (allocation.width, allocation.height);
}
static gboolean
gtk_gears_tick (GtkWidget *widget,
GdkFrameClock *frame_clock,
gpointer user_data)
{
GtkGears *gears = GTK_GEARS (widget);
GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
GdkFrameTimings *timings, *previous_timings;
gint64 previous_frame_time = 0;
gint64 frame_time;
gint64 history_start, history_len;
gint64 frame;
char *s;
frame = gdk_frame_clock_get_frame_counter (frame_clock);
frame_time = gdk_frame_clock_get_frame_time (frame_clock);
if (priv->first_frame_time == 0)
{
/* No need for changes on first frame */
priv->first_frame_time = frame_time;
if (priv->fps_label)
gtk_label_set_label (priv->fps_label, "FPS: ---");
return G_SOURCE_CONTINUE;
}
/* glxgears advances 70 degrees per second, so do the same */
priv->angle = fmod ((frame_time - priv->first_frame_time) / (double)G_USEC_PER_SEC * 70.0, 360.0);
gtk_widget_queue_draw (widget);
history_start = gdk_frame_clock_get_history_start (frame_clock);
if (priv->fps_label && frame % 60 == 0)
{
history_len = frame - history_start;
if (history_len > 0)
{
previous_timings = gdk_frame_clock_get_timings (frame_clock, frame - history_len);
previous_frame_time = gdk_frame_timings_get_frame_time (previous_timings);
s = g_strdup_printf ("FPS: %-4.1f", (G_USEC_PER_SEC * history_len) / (double)(frame_time - previous_frame_time));
gtk_label_set_label (priv->fps_label, s);
g_free (s);
}
}
timings = gdk_frame_clock_get_current_timings (frame_clock);
previous_timings = gdk_frame_clock_get_timings (frame_clock,
gdk_frame_timings_get_frame_counter (timings) - 1);
if (previous_timings != NULL)
previous_frame_time = gdk_frame_timings_get_frame_time (previous_timings);
return G_SOURCE_CONTINUE;
}
void
gtk_gears_set_axis (GtkGears *gears, int axis, double value)
{
GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
if (axis < 0 || axis >= GTK_GEARS_N_AXIS)
return;
priv->view_rot[axis] = value;
gtk_widget_queue_draw (GTK_WIDGET (gears));
}
double
gtk_gears_get_axis (GtkGears *gears, int axis)
{
GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
if (axis < 0 || axis >= GTK_GEARS_N_AXIS)
return 0.0;
return priv->view_rot[axis];
}
void
gtk_gears_set_fps_label (GtkGears *gears, GtkLabel *label)
{
GtkGearsPrivate *priv = gtk_gears_get_instance_private (gears);
if (label)
g_object_ref (label);
g_clear_object (&priv->fps_label);
priv->fps_label = label;
}