qbit/xenocara
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
8c9bfd57b8
xenocara/dist/Mesa/progs/demos/engine.c

1294 lines
29 KiB
C
Raw Normal View History

Import MesaDemos 6.5.1
2006-11-25 11:56:37 -07:00
/**
* Simple engine demo (crankshaft, pistons, connecting rods)
*
* Brian Paul
* June 2006
*/
#define GL_GLEXT_PROTOTYPES
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glut.h>
#include "readtex.h"
#include "trackball.h"
#define DEG_TO_RAD(DEG) ((DEG) * M_PI / 180.0)
#define TEXTURE_FILE "../images/reflect.rgb"
/* Target engine speed: */
const int RPM = 100.0;
/**
* Engine description.
*/
typedef struct
{
const char *Name;
int Pistons;
int Cranks;
float V_Angle;
float PistonRadius;
float PistonHeight;
float WristPinRadius;
float Throw;
float CrankPlateThickness;
float CrankPinRadius;
float CrankJournalRadius;
float CrankJournalLength;
float ConnectingRodLength;
float ConnectingRodThickness;
/* display list IDs */
GLuint CrankList;
GLuint ConnRodList;
GLuint PistonList;
GLuint BlockList;
} Engine;
typedef struct
{
float CurQuat[4];
float Distance;
/* When mouse is moving: */
GLboolean Rotating, Translating;
GLint StartX, StartY;
float StartDistance;
} ViewInfo;
typedef enum
{
LIT,
WIREFRAME,
TEXTURED
} RenderMode;
typedef struct
{
RenderMode Mode;
GLboolean Anim;
GLboolean Wireframe;
GLboolean Blend;
GLboolean Antialias;
GLboolean Texture;
GLboolean UseLists;
GLboolean DrawBox;
GLboolean ShowInfo;
GLboolean ShowBlock;
} RenderInfo;
static GLUquadric *Q;
static GLfloat Theta = 0.0;
static const GLfloat PistonColor[4] = { 1.0, 0.5, 0.5, 1.0 };
static const GLfloat ConnRodColor[4] = { 0.7, 1.0, 0.7, 1.0 };
static const GLfloat CrankshaftColor[4] = { 0.7, 0.7, 1.0, 1.0 };
static const GLfloat BlockColor[4] = {0.8, 0.8, 0.8, 0.75 };
static GLuint TextureObj;
static GLint WinWidth = 800, WinHeight = 500;
static ViewInfo View;
static RenderInfo Render;
#define NUM_ENGINES 3
static Engine Engines[NUM_ENGINES] =
{
{
"V-6",
6, /* Pistons */
3, /* Cranks */
90.0, /* V_Angle */
0.5, /* PistonRadius */
0.6, /* PistonHeight */
0.1, /* WristPinRadius */
0.5, /* Throw */
0.2, /* CrankPlateThickness */
0.25, /* CrankPinRadius */
0.3, /* CrankJournalRadius */
0.4, /* CrankJournalLength */
1.5, /* ConnectingRodLength */
0.1 /* ConnectingRodThickness */
},
{
"Inline-4",
4, /* Pistons */
4, /* Cranks */
0.0, /* V_Angle */
0.5, /* PistonRadius */
0.6, /* PistonHeight */
0.1, /* WristPinRadius */
0.5, /* Throw */
0.2, /* CrankPlateThickness */
0.25, /* CrankPinRadius */
0.3, /* CrankJournalRadius */
0.4, /* CrankJournalLength */
1.5, /* ConnectingRodLength */
0.1 /* ConnectingRodThickness */
},
{
"Boxer-6",
6, /* Pistons */
3, /* Cranks */
180.0,/* V_Angle */
0.5, /* PistonRadius */
0.6, /* PistonHeight */
0.1, /* WristPinRadius */
0.5, /* Throw */
0.2, /* CrankPlateThickness */
0.25, /* CrankPinRadius */
0.3, /* CrankJournalRadius */
0.4, /* CrankJournalLength */
1.5, /* ConnectingRodLength */
0.1 /* ConnectingRodThickness */
}
};
static int CurEngine = 0;
static void
InitViewInfo(ViewInfo *view)
{
view->Rotating = GL_FALSE;
view->Translating = GL_FALSE;
view->StartX = view->StartY = 0;
view->Distance = 12.0;
view->StartDistance = 0.0;
view->CurQuat[0] = -0.194143;
view->CurQuat[1] = 0.507848;
view->CurQuat[2] = 0.115245;
view->CurQuat[3] = 0.831335;
}
static void
InitRenderInfo(RenderInfo *render)
{
render->Mode = LIT;
render->Anim = GL_TRUE;
render->Wireframe = GL_FALSE;
render->Blend = GL_FALSE;
render->Antialias = GL_FALSE;
render->Texture = GL_FALSE;
render->DrawBox = GL_FALSE;
render->ShowInfo = GL_TRUE;
render->ShowBlock = GL_FALSE;
render->UseLists = GL_FALSE;
}
/**
* Set GL for given rendering mode.
*/
static void
SetRenderState(RenderMode mode)
{
static const GLfloat gray2[4] = { 0.2, 0.2, 0.2, 1.0 };
static const GLfloat gray4[4] = { 0.4, 0.4, 0.4, 1.0 };
/* defaults */
glDisable(GL_LIGHTING);
glDisable(GL_TEXTURE_2D);
glDisable(GL_BLEND);
glDisable(GL_LINE_SMOOTH);
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
glDisable(GL_TEXTURE_GEN_S);
glDisable(GL_TEXTURE_GEN_T);
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, gray2);
switch (mode) {
case LIT:
glEnable(GL_LIGHTING);
break;
case WIREFRAME:
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
glEnable(GL_LINE_SMOOTH);
glEnable(GL_BLEND);
glLineWidth(1.5);
break;
case TEXTURED:
glEnable(GL_LIGHTING);
glEnable(GL_TEXTURE_2D);
glEnable(GL_TEXTURE_GEN_S);
glEnable(GL_TEXTURE_GEN_T);
glLightModelfv(GL_LIGHT_MODEL_AMBIENT, gray4);
break;
default:
;
}
}
/**
* Animate the engine parts.
*/
static void
Idle(void)
{
/* convert degrees per millisecond to RPM: */
const float m = 360.0 / 1000.0 / 60.0;
GLint t = glutGet(GLUT_ELAPSED_TIME);
Theta = ((int) (t * RPM * m)) % 360;
glutPostRedisplay();
}
/**
* Compute piston's position along its stroke.
*/
static float
PistonStrokePosition(float throwDist, float crankAngle, float connRodLength)
{
float x = throwDist * cos(DEG_TO_RAD(crankAngle));
float y = throwDist * sin(DEG_TO_RAD(crankAngle));
float pos = y + sqrt(connRodLength * connRodLength - x * x);
return pos;
}
/**
* Compute position of nth piston along the crankshaft.
*/
static float
PistonShaftPosition(const Engine *eng, int piston)
{
const int i = piston / (eng->Pistons / eng->Cranks);
float z;
assert(piston < eng->Pistons);
z = 1.5 * eng->CrankJournalLength + eng->CrankPlateThickness
+ i * (2.0 * (eng->CrankJournalLength + eng->CrankPlateThickness));
if (eng->Pistons > eng->Cranks) {
if (piston & 1)
z += eng->ConnectingRodThickness;
else
z -= eng->ConnectingRodThickness;
}
return z;
}
/**
* Compute distance between two adjacent pistons
*/
static float
PistonSpacing(const Engine *eng)
{
const int pistonsPerCrank = eng->Pistons / eng->Cranks;
const float z0 = PistonShaftPosition(eng, 0);
const float z1 = PistonShaftPosition(eng, pistonsPerCrank);
return z1 - z0;
}
/**
* (x0, y0) = position of big end on crankshaft
* (x1, y1) = position of small end on piston
*/
static void
ComputeConnectingRodPosition(float throwDist, float crankAngle,
float connRodLength,
float *x0, float *y0, float *x1, float *y1)
{
*x0 = throwDist * cos(DEG_TO_RAD(crankAngle));
*y0 = throwDist * sin(DEG_TO_RAD(crankAngle));
*x1 = 0.0;
*y1 = PistonStrokePosition(throwDist, crankAngle, connRodLength);
}
/**
* Compute total length of the crankshaft.
*/
static float
CrankshaftLength(const Engine *eng)
{
float len = (eng->Cranks * 2 + 1) * eng->CrankJournalLength
+ 2 * eng->Cranks * eng->CrankPlateThickness;
return len;
}
/**
* Draw a piston.
* Axis of piston = Z axis. Wrist pin is centered on (0, 0, 0).
*/
static void
DrawPiston(const Engine *eng)
{
const int slices = 30, stacks = 4, loops = 4;
const float innerRadius = 0.9 * eng->PistonRadius;
const float innerHeight = eng->PistonHeight - 0.15;
const float wristPinLength = 1.8 * eng->PistonRadius;
assert(Q);
glPushMatrix();
glTranslatef(0, 0, -1.1 * eng->WristPinRadius);
gluQuadricOrientation(Q, GLU_INSIDE);
/* bottom rim */
gluDisk(Q, innerRadius, eng->PistonRadius, slices, 1/*loops*/);
/* inner cylinder */
gluCylinder(Q, innerRadius, innerRadius, innerHeight, slices, stacks);
/* inside top */
glPushMatrix();
glTranslatef(0, 0, innerHeight);
gluDisk(Q, 0, innerRadius, slices, loops);
glPopMatrix();
gluQuadricOrientation(Q, GLU_OUTSIDE);
/* outer cylinder */
gluCylinder(Q, eng->PistonRadius, eng->PistonRadius, eng->PistonHeight,
slices, stacks);
/* top */
glTranslatef(0, 0, eng->PistonHeight);
gluDisk(Q, 0, eng->PistonRadius, slices, loops);
glPopMatrix();
/* wrist pin */
glPushMatrix();
glTranslatef(0, 0.5 * wristPinLength, 0.0);
glRotatef(90, 1, 0, 0);
gluCylinder(Q, eng->WristPinRadius, eng->WristPinRadius, wristPinLength,
slices, stacks);
glPopMatrix();
}
/**
* Draw piston at particular position.
*/
static void
DrawPositionedPiston(const Engine *eng, float crankAngle)
{
const float pos = PistonStrokePosition(eng->Throw, crankAngle,
eng->ConnectingRodLength);
glPushMatrix();
glRotatef(-90, 1, 0, 0);
glTranslatef(0, 0, pos);
DrawPiston(eng);
glPopMatrix();
}
/**
* Draw connector plate. Used for crankshaft and connecting rods.
*/
static void
DrawConnector(float length, float thickness,
float bigEndRadius, float smallEndRadius)
{
const float bigRadius = 1.2 * bigEndRadius;
const float smallRadius = 1.2 * smallEndRadius;
const float z0 = -0.5 * thickness, z1 = -z0;
GLfloat points[36][2], normals[36][2];
int i;
/* compute vertex locations, normals */
for (i = 0; i < 36; i++) {
const int angle = i * 10;
float x = cos(DEG_TO_RAD(angle));
float y = sin(DEG_TO_RAD(angle));
normals[i][0] = x;
normals[i][1] = y;
if (angle >= 0 && angle <= 180) {
x *= smallRadius;
y = y * smallRadius + length;
}
else {
x *= bigRadius;
y *= bigRadius;
}
points[i][0] = x;
points[i][1] = y;
}
/* front face */
glNormal3f(0, 0, 1);
glBegin(GL_POLYGON);
for (i = 0; i < 36; i++) {
glVertex3f(points[i][0], points[i][1], z1);
}
glEnd();
/* back face */
glNormal3f(0, 0, -1);
glBegin(GL_POLYGON);
for (i = 0; i < 36; i++) {
glVertex3f(points[35-i][0], points[35-i][1], z0);
}
glEnd();
/* edge */
glBegin(GL_QUAD_STRIP);
for (i = 0; i <= 36; i++) {
const int j = i % 36;
glNormal3f(normals[j][0], normals[j][1], 0);
glVertex3f(points[j][0], points[j][1], z0);
glVertex3f(points[j][0], points[j][1], z1);
}
glEnd();
}
/**
* Draw a crankshaft. Shaft lies along +Z axis, starting at zero.
*/
static void
DrawCrankshaft(const Engine *eng)
{
const int slices = 20, stacks = 2;
const int n = eng->Cranks * 4 + 1;
const float phiStep = 360 / eng->Cranks;
float phi = -90.0;
int i;
float z = 0.0;
for (i = 0; i < n; i++) {
glPushMatrix();
glTranslatef(0, 0, z);
if (i & 1) {
/* draw a crank plate */
glRotatef(phi, 0, 0, 1);
glTranslatef(0, 0, 0.5 * eng->CrankPlateThickness);
DrawConnector(eng->Throw, eng->CrankPlateThickness,
eng->CrankJournalRadius, eng->CrankPinRadius);
z += 0.2;
if (i % 4 == 3)
phi += phiStep;
}
else if (i % 4 == 0) {
/* draw crank journal segment */
gluCylinder(Q, eng->CrankJournalRadius, eng->CrankJournalRadius,
eng->CrankJournalLength, slices, stacks);
z += eng->CrankJournalLength;
}
else if (i % 4 == 2) {
/* draw crank pin segment */
glRotatef(phi, 0, 0, 1);
glTranslatef(0, eng->Throw, 0);
gluCylinder(Q, eng->CrankPinRadius, eng->CrankPinRadius,
eng->CrankJournalLength, slices, stacks);
z += eng->CrankJournalLength;
}
glPopMatrix();
}
}
/**
* Draw crankshaft at a particular rotation.
* \param crankAngle current crankshaft rotation, in radians
*/
static void
DrawPositionedCrankshaft(const Engine *eng, float crankAngle)
{
glPushMatrix();
glRotatef(crankAngle, 0, 0, 1);
if (eng->CrankList)
glCallList(eng->CrankList);
else
DrawCrankshaft(eng);
glPopMatrix();
}
/**
* Draw a connecting rod at particular position.
* \param eng description of connecting rod to draw
* \param crankAngle current crankshaft rotation, in radians
*/
static void
DrawPositionedConnectingRod(const Engine *eng, float crankAngle)
{
float x0, y0, x1, y1;
float d, phi;
ComputeConnectingRodPosition(eng->Throw, crankAngle,
eng->ConnectingRodLength,
&x0, &y0, &x1, &y1);
d = sqrt(eng->ConnectingRodLength * eng->ConnectingRodLength - x0 * x0);
phi = atan(x0 / d) * 180.0 / M_PI;
glPushMatrix();
glTranslatef(x0, y0, 0);
glRotatef(phi, 0, 0, 1);
if (eng->ConnRodList)
glCallList(eng->ConnRodList);
else
DrawConnector(eng->ConnectingRodLength, eng->ConnectingRodThickness,
eng->CrankPinRadius, eng->WristPinRadius);
glPopMatrix();
}
/**
* Draw a square with a hole in middle.
*/
static void
SquareWithHole(float squareSize, float holeRadius)
{
int i;
glBegin(GL_QUAD_STRIP);
glNormal3f(0, 0, 1);
for (i = 0; i <= 360; i += 5) {
const float x1 = holeRadius * cos(DEG_TO_RAD(i));
const float y1 = holeRadius * sin(DEG_TO_RAD(i));
float x2, y2;
if (i > 315 || i <= 45) {
x2 = squareSize;
y2 = squareSize * tan(DEG_TO_RAD(i));
}
else if (i > 45 && i <= 135) {
x2 = -squareSize * tan(DEG_TO_RAD(i - 90));
y2 = squareSize;
}
else if (i > 135 && i <= 225) {
x2 = -squareSize;
y2 = -squareSize * tan(DEG_TO_RAD(i-180));
}
else if (i > 225 && i <= 315) {
x2 = squareSize * tan(DEG_TO_RAD(i - 270));
y2 = -squareSize;
}
glVertex2f(x1, y1); /* inner circle */
glVertex2f(x2, y2); /* outer square */
}
glEnd();
}
/**
* Draw block with hole through middle.
* Hole is centered on Z axis.
* Bottom of block is at z=0, top of block is at z = blockHeight.
* index is in [0, count - 1] to determine which block faces are drawn.
*/
static void
DrawBlockWithHole(float blockSize, float blockHeight, float holeRadius,
int index, int count)
{
const int slices = 30, stacks = 4;
const float x = blockSize;
const float y = blockSize;
const float z0 = 0;
const float z1 = blockHeight;
assert(index < count);
assert(Q);
gluQuadricOrientation(Q, GLU_INSIDE);
glBegin(GL_QUADS);
/* +X face */
glNormal3f(1, 0, 0);
glVertex3f( x, -y, z0);
glVertex3f( x, y, z0);
glVertex3f( x, y, z1);
glVertex3f( x, -y, z1);
/* -X face */
glNormal3f(-1, 0, 0);
glVertex3f(-x, -y, z1);
glVertex3f(-x, y, z1);
glVertex3f(-x, y, z0);
glVertex3f(-x, -y, z0);
if (index == 0) {
/* +Y face */
glNormal3f(0, 1, 0);
glVertex3f(-x, y, z1);
glVertex3f( x, y, z1);
glVertex3f( x, y, z0);
glVertex3f(-x, y, z0);
}
if (index == count - 1) {
/* -Y face */
glNormal3f(0, -1, 0);
glVertex3f(-x, -y, z0);
glVertex3f( x, -y, z0);
glVertex3f( x, -y, z1);
glVertex3f(-x, -y, z1);
}
glEnd();
/* cylinder / hole */
gluCylinder(Q, holeRadius, holeRadius, blockHeight, slices, stacks);
/* face at z0 */
glPushMatrix();
glRotatef(180, 1, 0, 0);
SquareWithHole(blockSize, holeRadius);
glPopMatrix();
/* face at z1 */
glTranslatef(0, 0, z1);
SquareWithHole(blockSize, holeRadius);
gluQuadricOrientation(Q, GLU_OUTSIDE);
}
/**
* Draw the engine block.
*/
static void
DrawEngineBlock(const Engine *eng)
{
const float blockHeight = eng->Throw + 1.5 * eng->PistonHeight;
const float cylRadius = 1.01 * eng->PistonRadius;
const float blockSize = 0.5 * PistonSpacing(eng);
const int pistonsPerCrank = eng->Pistons / eng->Cranks;
int i;
for (i = 0; i < eng->Pistons; i++) {
const float z = PistonShaftPosition(eng, i);
const int crank = i / pistonsPerCrank;
int k;
glPushMatrix();
glTranslatef(0, 0, z);
/* additional rotation for kth piston per crank */
k = i % pistonsPerCrank;
glRotatef(k * -eng->V_Angle, 0, 0, 1);
/* the block */
glRotatef(-90, 1, 0, 0);
glTranslatef(0, 0, eng->Throw * 2);
DrawBlockWithHole(blockSize, blockHeight, cylRadius,
crank, eng->Cranks);
glPopMatrix();
}
}
/**
* Generate display lists for engine parts.
*/
static void
GenerateDisplayLists(Engine *eng)
{
eng->CrankList = glGenLists(1);
glNewList(eng->CrankList, GL_COMPILE);
DrawCrankshaft(eng);
glEndList();
eng->ConnRodList = glGenLists(1);
glNewList(eng->ConnRodList, GL_COMPILE);
DrawConnector(eng->ConnectingRodLength, eng->ConnectingRodThickness,
eng->CrankPinRadius, eng->WristPinRadius);
glEndList();
eng->PistonList = glGenLists(1);
glNewList(eng->PistonList, GL_COMPILE);
DrawPiston(eng);
glEndList();
eng->BlockList = glGenLists(1);
glNewList(eng->BlockList, GL_COMPILE);
DrawEngineBlock(eng);
glEndList();
}
/**
* Free engine display lists (render with immediate mode).
*/
static void
FreeDisplayLists(Engine *eng)
{
glDeleteLists(eng->CrankList, 1);
eng->CrankList = 0;
glDeleteLists(eng->ConnRodList, 1);
eng->ConnRodList = 0;
glDeleteLists(eng->PistonList, 1);
eng->PistonList = 0;
glDeleteLists(eng->BlockList, 1);
eng->BlockList = 0;
}
/**
* Draw complete engine.
* \param eng description of engine to draw
* \param crankAngle current crankshaft angle, in radians
*/
static void
DrawEngine(const Engine *eng, float crankAngle)
{
const float crankDelta = 360.0 / eng->Cranks;
const float crankLen = CrankshaftLength(eng);
const int pistonsPerCrank = eng->Pistons / eng->Cranks;
int i;
glPushMatrix();
glRotatef(eng->V_Angle * 0.5, 0, 0, 1);
glTranslatef(0, 0, -0.5 * crankLen);
/* crankshaft */
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, CrankshaftColor);
glColor4fv(CrankshaftColor);
DrawPositionedCrankshaft(eng, crankAngle);
for (i = 0; i < eng->Pistons; i++) {
const float z = PistonShaftPosition(eng, i);
const int crank = i / pistonsPerCrank;
float rot = crankAngle + crank * crankDelta;
int k;
glPushMatrix();
glTranslatef(0, 0, z);
/* additional rotation for kth piston per crank */
k = i % pistonsPerCrank;
glRotatef(k * -eng->V_Angle, 0, 0, 1);
rot += k * eng->V_Angle;
/* piston */
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, PistonColor);
glColor4fv(PistonColor);
DrawPositionedPiston(eng, rot);
/* connecting rod */
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, ConnRodColor);
glColor4fv(ConnRodColor);
DrawPositionedConnectingRod(eng, rot);
glPopMatrix();
}
if (Render.ShowBlock) {
const GLboolean blend = glIsEnabled(GL_BLEND);
glDepthMask(GL_FALSE);
if (!blend) {
glEnable(GL_BLEND);
}
glEnable(GL_CULL_FACE);
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, BlockColor);
glColor4fv(BlockColor);
if (eng->CrankList)
glCallList(eng->BlockList);
else
DrawEngineBlock(eng);
glDisable(GL_CULL_FACE);
glDepthMask(GL_TRUE);
if (!blend) {
glDisable(GL_BLEND);
}
}
glPopMatrix();
}
static void
DrawBox(void)
{
const float xmin = -3.0, xmax = 3.0;
const float ymin = -1.0, ymax = 3.0;
const float zmin = -4.0, zmax = 4.0;
const float step = 0.5;
const float d = 0.01;
float x, y, z;
GLboolean lit = glIsEnabled(GL_LIGHTING);
GLboolean tex = glIsEnabled(GL_TEXTURE_2D);
glDisable(GL_LIGHTING);
glDisable(GL_TEXTURE_2D);
glColor3f(1, 1, 1);
/* Z min */
glBegin(GL_LINES);
for (x = xmin; x <= xmax; x += step) {
glVertex3f(x, ymin, zmin);
glVertex3f(x, ymax, zmin);
}
glEnd();
glBegin(GL_LINES);
for (y = ymin; y <= ymax; y += step) {
glVertex3f(xmin, y, zmin);
glVertex3f(xmax, y, zmin);
}
glEnd();
/* Y min */
glBegin(GL_LINES);
for (x = xmin; x <= xmax; x += step) {
glVertex3f(x, ymin, zmin);
glVertex3f(x, ymin, zmax);
}
glEnd();
glBegin(GL_LINES);
for (z = zmin; z <= zmax; z += step) {
glVertex3f(xmin, ymin, z);
glVertex3f(xmax, ymin, z);
}
glEnd();
/* X min */
glBegin(GL_LINES);
for (y = ymin; y <= ymax; y += step) {
glVertex3f(xmin, y, zmin);
glVertex3f(xmin, y, zmax);
}
glEnd();
glBegin(GL_LINES);
for (z = zmin; z <= zmax; z += step) {
glVertex3f(xmin, ymin, z);
glVertex3f(xmin, ymax, z);
}
glEnd();
glColor3f(0.4, 0.4, 0.6);
glBegin(GL_QUADS);
/* xmin */
glVertex3f(xmin-d, ymin, zmin);
glVertex3f(xmin-d, ymax, zmin);
glVertex3f(xmin-d, ymax, zmax);
glVertex3f(xmin-d, ymin, zmax);
/* ymin */
glVertex3f(xmin, ymin-d, zmin);
glVertex3f(xmax, ymin-d, zmin);
glVertex3f(xmax, ymin-d, zmax);
glVertex3f(xmin, ymin-d, zmax);
/* zmin */
glVertex3f(xmin, ymin, zmin-d);
glVertex3f(xmax, ymin, zmin-d);
glVertex3f(xmax, ymax, zmin-d);
glVertex3f(xmin, ymax, zmin-d);
glEnd();
if (lit)
glEnable(GL_LIGHTING);
if (tex)
glEnable(GL_TEXTURE_2D);
}
static void
PrintString(const char *s)
{
while (*s) {
glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
s++;
}
}
static int
ComputeFPS(void)
{
static double t0 = -1.0;
static int frames = 0;
double t = glutGet(GLUT_ELAPSED_TIME) / 1000.0;
static int fps = 0;
frames++;
if (t0 < 0.0) {
t0 = t;
fps = 0;
}
else if (t - t0 >= 1.0) {
fps = (int) (frames / (t - t0) + 0.5);
t0 = t;
frames = 0;
}
return fps;
}
static void
Draw(void)
{
int fps;
GLfloat rot[4][4];
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glTranslatef(0.0, 0.0, -View.Distance);
build_rotmatrix(rot, View.CurQuat);
glMultMatrixf(&rot[0][0]);
glPushMatrix();
glTranslatef(0, -0.75, 0);
if (Render.DrawBox)
DrawBox();
DrawEngine(Engines + CurEngine, Theta);
glPopMatrix();
glPopMatrix();
fps = ComputeFPS();
if (Render.ShowInfo) {
GLboolean lit = glIsEnabled(GL_LIGHTING);
GLboolean tex = glIsEnabled(GL_TEXTURE_2D);
char s[100];
sprintf(s, "%s %d FPS %s", Engines[CurEngine].Name, fps,
Render.UseLists ? "Display Lists" : "Immediate mode");
glDisable(GL_LIGHTING);
glDisable(GL_TEXTURE_2D);
glColor3f(1, 1 , 1);
glWindowPos2iARB(10, 10);
PrintString(s);
if (lit)
glEnable(GL_LIGHTING);
if (tex)
glEnable(GL_TEXTURE_2D);
}
glutSwapBuffers();
}
/**
* Handle window resize.
*/
static void
Reshape(int width, int height)
{
float ar = (float) width / height;
float s = 0.5;
glViewport(0, 0, width, height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glFrustum(-ar * s, ar * s, -s, s, 2.0, 50.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
WinWidth = width;
WinHeight = height;
}
/**
* Handle mouse button.
*/
static void
Mouse(int button, int state, int x, int y)
{
if (button == GLUT_LEFT_BUTTON) {
if (state == GLUT_DOWN) {
View.StartX = x;
View.StartY = y;
View.Rotating = GL_TRUE;
}
else if (state == GLUT_UP) {
View.Rotating = GL_FALSE;
}
}
else if (button == GLUT_MIDDLE_BUTTON) {
if (state == GLUT_DOWN) {
View.StartX = x;
View.StartY = y;
View.StartDistance = View.Distance;
View.Translating = GL_TRUE;
}
else if (state == GLUT_UP) {
View.Translating = GL_FALSE;
}
}
}
/**
* Handle mouse motion
*/
static void
Motion(int x, int y)
{
int i;
if (View.Rotating) {
float x0 = (2.0 * View.StartX - WinWidth) / WinWidth;
float y0 = (WinHeight - 2.0 * View.StartY) / WinHeight;
float x1 = (2.0 * x - WinWidth) / WinWidth;
float y1 = (WinHeight - 2.0 * y) / WinHeight;
float q[4];
trackball(q, x0, y0, x1, y1);
View.StartX = x;
View.StartY = y;
for (i = 0; i < 1; i++)
add_quats(q, View.CurQuat, View.CurQuat);
glutPostRedisplay();
}
else if (View.Translating) {
float dz = 0.01 * (y - View.StartY);
View.Distance = View.StartDistance + dz;
glutPostRedisplay();
}
}
/**
** Menu Callbacks
**/
static void
OptAnimation(void)
{
Render.Anim = !Render.Anim;
if (Render.Anim)
glutIdleFunc(Idle);
else
glutIdleFunc(NULL);
}
static void
OptChangeEngine(void)
{
CurEngine = (CurEngine + 1) % NUM_ENGINES;
}
static void
OptRenderMode(void)
{
Render.Mode++;
if (Render.Mode > TEXTURED)
Render.Mode = 0;
SetRenderState(Render.Mode);
}
static void
OptDisplayLists(void)
{
int i;
Render.UseLists = !Render.UseLists;
if (Render.UseLists) {
for (i = 0; i < NUM_ENGINES; i++) {
GenerateDisplayLists(Engines + i);
}
}
else {
for (i = 0; i < NUM_ENGINES; i++) {
FreeDisplayLists(Engines + i);
}
}
}
static void
OptShowBlock(void)
{
Render.ShowBlock = !Render.ShowBlock;
}
static void
OptShowInfo(void)
{
Render.ShowInfo = !Render.ShowInfo;
}
static void
OptShowBox(void)
{
Render.DrawBox = !Render.DrawBox;
}
static void
OptRotate(void)
{
Theta += 5.0;
}
static void
OptExit(void)
{
exit(0);
}
/**
* Define menu entries (w/ keyboard shortcuts)
*/
typedef struct
{
const char *Text;
const char Key;
void (*Function)(void);
} MenuInfo;
static const MenuInfo MenuItems[] = {
{ "Animation", 'a', OptAnimation },
{ "Change Engine", 'e', OptChangeEngine },
{ "Rendering Style", 'm', OptRenderMode },
{ "Display Lists", 'd', OptDisplayLists },
{ "Show Block", 'b', OptShowBlock },
{ "Show Info", 'i', OptShowInfo },
{ "Show Box", 'x', OptShowBox },
{ "Exit", 27, OptExit },
{ NULL, 'r', OptRotate },
{ NULL, 0, NULL }
};
/**
* Handle menu selection.
*/
static void
MenuHandler(int entry)
{
MenuItems[entry].Function();
glutPostRedisplay();
}
/**
* Make pop-up menu.
*/
static void
MakeMenu(void)
{
int i;
glutCreateMenu(MenuHandler);
for (i = 0; MenuItems[i].Text; i++) {
glutAddMenuEntry(MenuItems[i].Text, i);
}
glutAttachMenu(GLUT_RIGHT_BUTTON);
}
/**
* Handle keyboard event.
*/
static void
Key(unsigned char key, int x, int y)
{
int i;
(void) x; (void) y;
for (i = 0; MenuItems[i].Key; i++) {
if (MenuItems[i].Key == key) {
MenuItems[i].Function();
glutPostRedisplay();
break;
}
}
}
static
void LoadTexture(void)
{
GLboolean convolve = GL_FALSE;
glGenTextures(1, &TextureObj);
glBindTexture(GL_TEXTURE_2D, TextureObj);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP);
glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP);
if (convolve) {
#define FILTER_SIZE 7
/* use convolution to blur the texture to simulate a dull finish
* on the object.
*/
GLubyte *img;
GLenum format;
GLint w, h;
GLfloat filter[FILTER_SIZE][FILTER_SIZE][4];
for (h = 0; h < FILTER_SIZE; h++) {
for (w = 0; w < FILTER_SIZE; w++) {
const GLfloat k = 1.0 / (FILTER_SIZE * FILTER_SIZE);
filter[h][w][0] = k;
filter[h][w][1] = k;
filter[h][w][2] = k;
filter[h][w][3] = k;
}
}
glEnable(GL_CONVOLUTION_2D);
glConvolutionParameteri(GL_CONVOLUTION_2D,
GL_CONVOLUTION_BORDER_MODE, GL_CONSTANT_BORDER);
glConvolutionFilter2D(GL_CONVOLUTION_2D, GL_RGBA,
FILTER_SIZE, FILTER_SIZE,
GL_RGBA, GL_FLOAT, filter);
img = LoadRGBImage(TEXTURE_FILE, &w, &h, &format);
if (!img) {
printf("Error: couldn't load texture image file %s\n", TEXTURE_FILE);
exit(1);
}
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, w, h, 0,
format, GL_UNSIGNED_BYTE, img);
free(img);
}
else {
if (!LoadRGBMipmaps(TEXTURE_FILE, GL_RGB)) {
printf("Error: couldn't load texture image file %s\n", TEXTURE_FILE);
exit(1);
}
}
}
static void
Init(void)
{
const GLfloat lightColor[4] = { 0.7, 0.7, 0.7, 1.0 };
const GLfloat specular[4] = { 0.8, 0.8, 0.8, 1.0 };
Q = gluNewQuadric();
gluQuadricNormals(Q, GLU_SMOOTH);
LoadTexture();
glClearColor(0.3, 0.3, 0.3, 0.0);
glEnable(GL_DEPTH_TEST);
glEnable(GL_LIGHTING);
glEnable(GL_LIGHT0);
glLightfv(GL_LIGHT0, GL_DIFFUSE, lightColor);
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 40);
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
glEnable(GL_NORMALIZE);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
InitViewInfo(&View);
InitRenderInfo(&Render);
}
int
main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitWindowSize(WinWidth, WinHeight);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
glutCreateWindow("OpenGL Engine Demo");
glutReshapeFunc(Reshape);
glutMouseFunc(Mouse);
glutMotionFunc(Motion);
glutKeyboardFunc(Key);
glutDisplayFunc(Draw);
MakeMenu();
Init();
if (Render.Anim)
glutIdleFunc(Idle);
glutMainLoop();
return 0;
}
Reference in New Issue Copy Permalink