+++ /dev/null
-/*
- * Copyright (C) 2009 Chia-I Wu <olv@0xlab.org>
- *
- * Based on eglgears by
- * 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 <stdlib.h>
-#include <stdio.h>
-#include <math.h>
-#include <assert.h>
-
-#include <GLES/gl.h>
-#include "eglut.h"
-
-#ifndef M_PI
-#define M_PI 3.14159265
-#endif
-
-
-struct gear {
- GLuint vbo;
- GLfloat *vertices;
- GLsizei stride;
-
- GLint num_teeth;
-};
-
-static GLfloat view_rotx = 20.0, view_roty = 30.0, view_rotz = 0.0;
-static struct gear gears[3];
-static GLfloat angle = 0.0;
-
-/*
- * Initialize a gear wheel.
- *
- * Input: gear - gear to initialize
- * 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
-init_gear(struct gear *gear, GLfloat inner_radius, GLfloat outer_radius,
- GLfloat width, GLint teeth, GLfloat tooth_depth)
-{
- GLfloat r0, r1, r2;
- GLfloat a0, da;
- GLint verts_per_tooth, total_verts, total_size;
- GLint count, i;
- GLfloat *verts;
-
- r0 = inner_radius;
- r1 = outer_radius - tooth_depth / 2.0;
- r2 = outer_radius + tooth_depth / 2.0;
-
- a0 = 2.0 * M_PI / teeth;
- da = a0 / 4.0;
-
- gear->vbo = 0;
- gear->vertices = NULL;
- gear->stride = sizeof(GLfloat) * 6; /* XYZ + normal */
- gear->num_teeth = teeth;
-
- verts_per_tooth = 10 + 4;
- total_verts = teeth * verts_per_tooth;
- total_size = total_verts * gear->stride;
-
- verts = malloc(total_size);
- if (!verts) {
- printf("failed to allocate vertices\n");
- return;
- }
-
-#define GEAR_VERT(r, n, sign) \
- do { \
- verts[count * 6 + 0] = (r) * vx[n]; \
- verts[count * 6 + 1] = (r) * vy[n]; \
- verts[count * 6 + 2] = (sign) * width * 0.5; \
- verts[count * 6 + 3] = normal[0]; \
- verts[count * 6 + 4] = normal[1]; \
- verts[count * 6 + 5] = normal[2]; \
- count++; \
- } while (0)
-
- count = 0;
- for (i = 0; i < teeth; i++) {
- GLfloat normal[3];
- GLfloat vx[5], vy[5];
- GLfloat u, v;
-
- normal[0] = 0.0;
- normal[1] = 0.0;
- normal[2] = 0.0;
-
- vx[0] = cos(i * a0 + 0 * da);
- vy[0] = sin(i * a0 + 0 * da);
- vx[1] = cos(i * a0 + 1 * da);
- vy[1] = sin(i * a0 + 1 * da);
- vx[2] = cos(i * a0 + 2 * da);
- vy[2] = sin(i * a0 + 2 * da);
- vx[3] = cos(i * a0 + 3 * da);
- vy[3] = sin(i * a0 + 3 * da);
- vx[4] = cos(i * a0 + 4 * da);
- vy[4] = sin(i * a0 + 4 * da);
-
- /* outward faces of a tooth, 10 verts */
- normal[0] = vx[0];
- normal[1] = vy[0];
- GEAR_VERT(r1, 0, 1);
- GEAR_VERT(r1, 0, -1);
-
- u = r2 * vx[1] - r1 * vx[0];
- v = r2 * vy[1] - r1 * vy[0];
- normal[0] = v;
- normal[1] = -u;
- GEAR_VERT(r2, 1, 1);
- GEAR_VERT(r2, 1, -1);
-
- normal[0] = vx[0];
- normal[1] = vy[0];
- GEAR_VERT(r2, 2, 1);
- GEAR_VERT(r2, 2, -1);
-
- u = r1 * vx[3] - r2 * vx[2];
- v = r1 * vy[3] - r2 * vy[2];
- normal[0] = v;
- normal[1] = -u;
- GEAR_VERT(r1, 3, 1);
- GEAR_VERT(r1, 3, -1);
-
- normal[0] = vx[0];
- normal[1] = vy[0];
- GEAR_VERT(r1, 4, 1);
- GEAR_VERT(r1, 4, -1);
-
- /* inside radius cylinder, 4 verts */
- normal[0] = -vx[4];
- normal[1] = -vy[4];
- GEAR_VERT(r0, 4, 1);
- GEAR_VERT(r0, 4, -1);
-
- normal[0] = -vx[0];
- normal[1] = -vy[0];
- GEAR_VERT(r0, 0, 1);
- GEAR_VERT(r0, 0, -1);
-
- assert(count % verts_per_tooth == 0);
- }
- assert(count == total_verts);
-#undef GEAR_VERT
-
- gear->vertices = verts;
-
- /* setup VBO */
- glGenBuffers(1, &gear->vbo);
- if (gear->vbo) {
- glBindBuffer(GL_ARRAY_BUFFER, gear->vbo);
- glBufferData(GL_ARRAY_BUFFER, total_size, verts, GL_STATIC_DRAW);
- }
-}
-
-
-static void
-draw_gear(const struct gear *gear)
-{
- GLint i;
-
- if (!gear->vbo && !gear->vertices) {
- printf("nothing to be drawn\n");
- return;
- }
-
- if (gear->vbo) {
- glBindBuffer(GL_ARRAY_BUFFER, gear->vbo);
- glVertexPointer(3, GL_FLOAT, gear->stride, (const GLvoid *) 0);
- glNormalPointer(GL_FLOAT, gear->stride, (const GLvoid *) (sizeof(GLfloat) * 3));
- } else {
- glBindBuffer(GL_ARRAY_BUFFER, 0);
- glVertexPointer(3, GL_FLOAT, gear->stride, gear->vertices);
- glNormalPointer(GL_FLOAT, gear->stride, gear->vertices + 3);
- }
-
- glEnableClientState(GL_VERTEX_ARRAY);
-
- for (i = 0; i < gear->num_teeth; i++) {
- const GLint base = (10 + 4) * i;
- GLushort indices[7];
-
- glShadeModel(GL_FLAT);
-
- /* front face */
- indices[0] = base + 12;
- indices[1] = base + 0;
- indices[2] = base + 2;
- indices[3] = base + 4;
- indices[4] = base + 6;
- indices[5] = base + 8;
- indices[6] = base + 10;
-
- glNormal3f(0.0, 0.0, 1.0);
- glDrawElements(GL_TRIANGLE_FAN, 7, GL_UNSIGNED_SHORT, indices);
-
- /* back face */
- indices[0] = base + 13;
- indices[1] = base + 11;
- indices[2] = base + 9;
- indices[3] = base + 7;
- indices[4] = base + 5;
- indices[5] = base + 3;
- indices[6] = base + 1;
-
- glNormal3f(0.0, 0.0, -1.0);
- glDrawElements(GL_TRIANGLE_FAN, 7, GL_UNSIGNED_SHORT, indices);
-
- glEnableClientState(GL_NORMAL_ARRAY);
-
- /* outward face of a tooth */
- glDrawArrays(GL_TRIANGLE_STRIP, base, 10);
-
- /* inside radius cylinder */
- glShadeModel(GL_SMOOTH);
- glDrawArrays(GL_TRIANGLE_STRIP, base + 10, 4);
-
- glDisableClientState(GL_NORMAL_ARRAY);
- }
-
- glDisableClientState(GL_VERTEX_ARRAY);
-}
-
-
-static void
-gears_draw(void)
-{
- static const GLfloat red[4] = { 0.8, 0.1, 0.0, 1.0 };
- static const GLfloat green[4] = { 0.0, 0.8, 0.2, 1.0 };
- static const GLfloat blue[4] = { 0.2, 0.2, 1.0, 1.0 };
-
- glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
-
- glPushMatrix();
- glRotatef(view_rotx, 1.0, 0.0, 0.0);
- glRotatef(view_roty, 0.0, 1.0, 0.0);
- glRotatef(view_rotz, 0.0, 0.0, 1.0);
-
- glPushMatrix();
- glTranslatef(-3.0, -2.0, 0.0);
- glRotatef(angle, 0.0, 0.0, 1.0);
-
- glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, red);
- draw_gear(&gears[0]);
-
- glPopMatrix();
-
- glPushMatrix();
- glTranslatef(3.1, -2.0, 0.0);
- glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0);
-
- glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, green);
- draw_gear(&gears[1]);
-
- glPopMatrix();
-
- glPushMatrix();
- glTranslatef(-3.1, 4.2, 0.0);
- glRotatef(-2.0 * angle - 25.0, 0.0, 0.0, 1.0);
-
- glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, blue);
- draw_gear(&gears[2]);
-
- glPopMatrix();
-
- glPopMatrix();
-}
-
-
-static void gears_fini(void)
-{
- GLint i;
- for (i = 0; i < 3; i++) {
- struct gear *gear = &gears[i];
- if (gear->vbo) {
- glDeleteBuffers(1, &gear->vbo);
- gear->vbo = 0;
- }
- if (gear->vertices) {
- free(gear->vertices);
- gear->vertices = NULL;
- }
- }
-}
-
-
-static void gears_init(void)
-{
- static const GLfloat pos[4] = { 5.0, 5.0, 10.0, 0.0 };
-
- glLightfv(GL_LIGHT0, GL_POSITION, pos);
- glEnable(GL_CULL_FACE);
- glEnable(GL_LIGHTING);
- glEnable(GL_LIGHT0);
- glEnable(GL_DEPTH_TEST);
- glEnable(GL_NORMALIZE);
-
- init_gear(&gears[0], 1.0, 4.0, 1.0, 20, 0.7);
- init_gear(&gears[1], 0.5, 2.0, 2.0, 10, 0.7);
- init_gear(&gears[2], 1.3, 2.0, 0.5, 10, 0.7);
-}
-
-
-/* new window size or exposure */
-static void
-gears_reshape(int width, int height)
-{
- GLfloat h = (GLfloat) height / (GLfloat) width;
-
- glViewport(0, 0, (GLint) width, (GLint) height);
-
- glMatrixMode(GL_PROJECTION);
- glLoadIdentity();
- glFrustumf(-1.0, 1.0, -h, h, 5.0, 60.0);
-
- glMatrixMode(GL_MODELVIEW);
- glLoadIdentity();
- glTranslatef(0.0, 0.0, -40.0);
-}
-
-
-static void
-gears_idle(void)
-{
- static double t0 = -1.;
- double dt, t = eglutGet(EGLUT_ELAPSED_TIME) / 1000.0;
- if (t0 < 0.0)
- t0 = t;
- dt = t - t0;
- t0 = t;
-
- angle += 70.0 * dt; /* 70 degrees per second */
- angle = fmod(angle, 360.0); /* prevents eventual overflow */
-
- eglutPostRedisplay();
-}
-
-
-int
-main(int argc, char *argv[])
-{
- eglutInitWindowSize(300, 300);
- eglutInitAPIMask(EGLUT_OPENGL_ES1_BIT);
- eglutInit(argc, argv);
-
- eglutCreateWindow("gears");
-
- eglutIdleFunc(gears_idle);
- eglutReshapeFunc(gears_reshape);
- eglutDisplayFunc(gears_draw);
-
- gears_init();
-
- eglutMainLoop();
-
- gears_fini();
-
- return 0;
-}
projects / mesa.git / blobdiff