ref: 41b182552016aaf23ae7bfa0133f45668a16905e
dir: /Raw_Demos/gears.c/
/* sdlGears.c */
/*
* 3-D gear wheels by Brian Paul. This program is in the public domain.
*
* ported to libSDL/TinyGL by Gerald Franz (gfz@o2online.de)
*/
//#define PLAY_MUSIC
//Only C standard library includes.
//These are ALL the external dependencies of this program!!! ALL of them!!!
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
//Doesn't drag in anything.
#include "../include/GL/gl.h"
//Doesn't drag in anything.
#include "../include/zbuffer.h"
#define CHAD_MATH_IMPL
//Drags in Math and String (which are already dragged in above.)
#include "../include-demo/3dMath.h"
//Requires
/*
#include <math.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
and
#include <assert.h>
if I didn't define STBIW_ASSERT
*/
#define STBIW_ASSERT(x) /* a comment */
#define STB_IMAGE_WRITE_IMPLEMENTATION
#include "../include-demo/stb_image_write.h"
typedef unsigned char uchar;
#ifndef M_PI
#define M_PI 3.14159265
#endif
int override_drawmodes = 0;
GLubyte stipplepattern[128] = {0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55,
0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55, 0xAA, 0xAA, 0xAA, 0xAA, 0x55, 0x55, 0x55, 0x55};
/*
* 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 * M_PI / teeth / 4.0;
glNormal3f(0.0, 0.0, 1.0);
/* draw front face */
if(override_drawmodes == 1)
glBegin(GL_LINES);
else if (override_drawmodes == 2)
glBegin(GL_POINTS);
else
{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);
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 */
if(override_drawmodes == 1)
glBegin(GL_LINES);
else if (override_drawmodes == 2)
glBegin(GL_POINTS);
else
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 */
if(override_drawmodes == 1)
glBegin(GL_LINES);
else if (override_drawmodes == 2)
glBegin(GL_POINTS);
else
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);
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 */
if(override_drawmodes == 1)
glBegin(GL_LINES);
else if (override_drawmodes == 2)
glBegin(GL_POINTS);
else
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 */
if(override_drawmodes == 1)
glBegin(GL_LINES);
else if (override_drawmodes == 2)
glBegin(GL_POINTS);
else
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();
/* draw inside radius cylinder */
if(override_drawmodes == 1)
glBegin(GL_LINES);
else if (override_drawmodes == 2)
glBegin(GL_POINTS);
else
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();
}
static GLfloat view_rotx = 20.0, view_roty = 30.0;
static GLint gear1, gear2, gear3;
static GLfloat angle = 0.0;
void draw() {
angle += 2.0;
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);
glCallList(gear1);
glPopMatrix();
glPushMatrix();
glTranslatef(3.1, -2.0, 0.0);
glRotatef(-2.0 * angle - 9.0, 0.0, 0.0, 1.0);
glCallList(gear2);
glPopMatrix();
glPushMatrix();
glTranslatef(-3.1, 4.2, 0.0);
glRotatef(-2.0 * angle - 25.0, 0.0, 0.0, 1.0);
glCallList(gear3);
glPopMatrix();
glPopMatrix();
}
void initScene() {
// static GLfloat pos[4] = {0.408248290463863, 0.408248290463863, 0.816496580927726, 0.0 }; //Light at infinity.
static GLfloat pos[4] = {5, 5, 10, 0.0}; // Light at infinity.
//static GLfloat pos[4] = {5, 5, -10, 0.0}; // Light at infinity.
static GLfloat red[4] = {1.0, 0.0, 0.0, 0.0};
static GLfloat green[4] = {0.0, 1.0, 0.0, 0.0};
static GLfloat blue[4] = {0.0, 0.0, 1.0, 0.0};
static GLfloat white[4] = {1.0, 1.0, 1.0, 0.0};
static GLfloat shininess = 5;
glLightfv(GL_LIGHT0, GL_POSITION, pos);
glLightfv(GL_LIGHT0, GL_DIFFUSE, white);
// glLightfv( GL_LIGHT0, GL_AMBIENT, white);
glLightfv( GL_LIGHT0, GL_SPECULAR, white);
glEnable(GL_CULL_FACE);
glEnable(GL_LIGHT0);
//glEnable(GL_DEPTH_TEST);
glEnable(GL_POLYGON_STIPPLE);
// glDisable(GL_POLYGON_STIPPLE);
glPolygonStipple(stipplepattern);
glPointSize(10.0f);
glTextSize(GL_TEXT_SIZE24x24);
/* make the gears */
gear1 = glGenLists(1);
glNewList(gear1, GL_COMPILE);
glMaterialfv(GL_FRONT, GL_DIFFUSE, blue);
glMaterialfv(GL_FRONT, GL_SPECULAR, white);
glMaterialfv(GL_FRONT, GL_SHININESS, &shininess);
glColor3fv(blue);
gear(1.0, 4.0, 1.0, 20, 0.7); // The largest gear.
glEndList();
gear2 = glGenLists(1);
glNewList(gear2, GL_COMPILE);
glMaterialfv(GL_FRONT, GL_DIFFUSE, red);
glMaterialfv(GL_FRONT, GL_SPECULAR, white);
glColor3fv(red);
gear(0.5, 2.0, 2.0, 10, 0.7); // The small gear with the smaller hole, to the right.
glEndList();
gear3 = glGenLists(1);
glNewList(gear3, GL_COMPILE);
glMaterialfv(GL_FRONT, GL_DIFFUSE, green);
glMaterialfv(GL_FRONT, GL_SPECULAR, white);
glColor3fv(green);
gear(1.3, 2.0, 0.5, 10, 0.7); // The small gear above with the large hole.
glEndList();
// glEnable( GL_NORMALIZE );
}
int main(int argc, char** argv) {
// initialize SDL video:
int winSizeX = 640;
int winSizeY = 480;
PIXEL* imbuf = NULL;
uchar* pbuf = NULL;
unsigned int flat = 0;
unsigned int setenspec = 1;
unsigned int dotext = 1;
unsigned int blending = 0;
if (argc > 1) {
char* larg = "";
for (int i = 1; i < argc; i++) {
if (!strcmp(larg, "-w"))
winSizeX = atoi(argv[i]);
if (!strcmp(larg, "-h"))
winSizeY = atoi(argv[i]);
if (!strcmp(argv[i],"-flat"))
flat = 1;
if (!strcmp(argv[i],"-smooth"))
flat = 0;
if (!strcmp(argv[i],"-blend"))
blending = 1;
if (!strcmp(argv[i],"-nospecular"))
setenspec = 0;
if (!strcmp(argv[i],"-lines"))
override_drawmodes = 1;
if (!strcmp(argv[i],"-points"))
override_drawmodes = 2;
if (!strcmp(argv[i],"-notext"))
dotext = 0;
larg = argv[i];
}
}
fflush(stdout);
imbuf = calloc(1,sizeof(PIXEL) * winSizeX * winSizeY);
// initialize TinyGL:
// unsigned int pitch;
//int mode;
ZBuffer* frameBuffer = NULL;
if(TGL_FEATURE_RENDER_BITS == 32)
frameBuffer = ZB_open(winSizeX, winSizeY, ZB_MODE_RGBA, 0);
else
frameBuffer = ZB_open(winSizeX, winSizeY, ZB_MODE_5R6G5B, 0);
if(!frameBuffer){printf("\nZB_open failed!");exit(1);}
glInit(frameBuffer);
//Print version info
printf("\nVersion string:\n%s",glGetString(GL_VERSION));
printf("\nVendor string:\n%s",glGetString(GL_VENDOR));
printf("\nRenderer string:\n%s",glGetString(GL_RENDERER));
printf("\nExtensions string:\n%s",glGetString(GL_EXTENSIONS));
printf("\nLicense string:\n%s",glGetString(GL_LICENSE));
// initialize GL:
glClearColor(0.0, 0.0, 0.0, 0.0);
glViewport(0, 0, winSizeX, winSizeY);
if(flat) glShadeModel(GL_FLAT); else glShadeModel(GL_SMOOTH);
//TESTING BLENDING...
//glDisable(GL_DEPTH_TEST);
//glDisable( GL_LIGHTING );
glEnable(GL_LIGHTING);
//glBlendFunc(GL_ONE_MINUS_SRC_COLOR, GL_ZERO);
glBlendEquation(GL_FUNC_ADD);
if(blending){
glDisable(GL_DEPTH_TEST);
glEnable(GL_BLEND);
glDepthMask(GL_FALSE);
glBlendFunc(GL_ONE_MINUS_SRC_COLOR, GL_DST_COLOR);
glBlendEquation(GL_FUNC_ADD);
}else{
glEnable(GL_DEPTH_TEST);
glDisable(GL_BLEND);
glDepthMask(GL_TRUE);
}
GLfloat h = (GLfloat)winSizeY / (GLfloat)winSizeX;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-1.0, 1.0, -h, h, 5.0, 60.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0.0, 0.0, -45.0);
initScene();
if(setenspec) glSetEnableSpecular(GL_TRUE); else glSetEnableSpecular(GL_FALSE);
// variables for timing:
unsigned int frames = 0;
//unsigned int tLastFps = tNow;
// main loop:
int isRunning = 1;
//float test = 0;
while (isRunning) {
++frames;
//Depending on SDL to give us ticks even without a window open...
// test = TEST_fastInvSqrt(tNow);
// printf("\n%f",test);
// do event handling:
// draw scene:
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
draw();
if(dotext){
glDrawText((unsigned char*)"RED text", 0, 0, 0xFF0000);
glDrawText((unsigned char*)"GREEN text", 0, 24, 0x00FF00);
glDrawText((unsigned char*)"BLUE text", 0, 48, 0xFF);
}
// swap buffers:
// Quickly convert all pixels to the correct format
ZB_copyFrameBuffer(frameBuffer, imbuf, winSizeX * sizeof(PIXEL));
if(frames > 0) break;
}
if(TGL_FEATURE_RENDER_BITS == 32){ //very little conversion.
pbuf = malloc(3 * winSizeX * winSizeY);
for(int i = 0; i < winSizeX * winSizeY; i++){
//pbuf[3*i+0] = (imbuf[i]&0xff0000)>>16;
//pbuf[3*i+1] = (imbuf[i]&0x00ff00)>>8;
//pbuf[3*i+2] = (imbuf[i]&0x0000ff);
pbuf[3*i+0] = GET_RED(imbuf[i]);
pbuf[3*i+1] = GET_GREEN(imbuf[i]);
pbuf[3*i+2] = GET_BLUE(imbuf[i]);
}
stbi_write_png("render.png", winSizeX, winSizeY, 3, pbuf, 0);
free(imbuf);
free(pbuf);
} else if(TGL_FEATURE_RENDER_BITS == 16){
puts("\nTesting 16 bit rendering...\n");
pbuf = malloc(3 * winSizeX * winSizeY);
for(int i = 0; i < winSizeX * winSizeY; i++){
pbuf[3*i+0] = GET_RED(imbuf[i]);
pbuf[3*i+1] = GET_GREEN(imbuf[i]);
pbuf[3*i+2] = GET_BLUE(imbuf[i]);
}
stbi_write_png("render.png", winSizeX, winSizeY, 3, pbuf, 0);
free(imbuf);
free(pbuf);
}
// cleanup:
glDeleteList(gear1);
glDeleteList(gear2);
glDeleteList(gear3);
//ZB_close(frameBuffer);
glClose();
glInit(frameBuffer);
glClose();
glInit(frameBuffer);
glClose();
glInit(frameBuffer);
glClose();
glInit(frameBuffer);
ZB_close(frameBuffer);
glClose();
return 0;
}