/** * 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" #ifndef M_PI #define M_PI 3.14159265358979323846 #endif #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], z1); glVertex3f(points[j][0], points[j][1], z0); } 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, 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, GL_AMBIENT_AND_DIFFUSE, PistonColor); glColor4fv(PistonColor); DrawPositionedPiston(eng, rot); /* connecting rod */ glMaterialfv(GL_FRONT, 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, 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 }; const GLfloat backColor[4] = { 1, 1, 0, 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, GL_SHININESS, 40); glMaterialfv(GL_FRONT, GL_SPECULAR, specular); glEnable(GL_NORMALIZE); glMaterialfv(GL_BACK, GL_DIFFUSE, backColor); #if 0 glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, 1); #endif 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; }