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-rw-r--r--progs/demos/engine.c216
1 files changed, 205 insertions, 11 deletions
diff --git a/progs/demos/engine.c b/progs/demos/engine.c
index 8ef7346217..143b02a889 100644
--- a/progs/demos/engine.c
+++ b/progs/demos/engine.c
@@ -47,6 +47,7 @@ typedef struct
GLuint CrankList;
GLuint ConnRodList;
GLuint PistonList;
+ GLuint BlockList;
} Engine;
@@ -80,6 +81,7 @@ typedef struct
GLboolean UseLists;
GLboolean DrawBox;
GLboolean ShowInfo;
+ GLboolean ShowBlock;
} RenderInfo;
@@ -87,9 +89,10 @@ static GLUquadric *Q;
static GLfloat Theta = 0.0;
-static GLfloat PistonColor[4] = { 1.0, 0.5, 0.5, 1.0 };
-static GLfloat ConnRodColor[4] = { 0.7, 1.0, 0.7, 1.0 };
-static GLfloat CrankshaftColor[4] = { 0.7, 0.7, 1.0, 1.0 };
+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;
@@ -113,7 +116,7 @@ static Engine Engines[NUM_ENGINES] =
0.25, /* CrankPinRadius */
0.3, /* CrankJournalRadius */
0.4, /* CrankJournalLength */
- 1.3, /* ConnectingRodLength */
+ 1.5, /* ConnectingRodLength */
0.1 /* ConnectingRodThickness */
},
{
@@ -129,7 +132,7 @@ static Engine Engines[NUM_ENGINES] =
0.25, /* CrankPinRadius */
0.3, /* CrankJournalRadius */
0.4, /* CrankJournalLength */
- 1.3, /* ConnectingRodLength */
+ 1.5, /* ConnectingRodLength */
0.1 /* ConnectingRodThickness */
},
{
@@ -145,7 +148,7 @@ static Engine Engines[NUM_ENGINES] =
0.25, /* CrankPinRadius */
0.3, /* CrankJournalRadius */
0.4, /* CrankJournalLength */
- 1.3, /* ConnectingRodLength */
+ 1.5, /* ConnectingRodLength */
0.1 /* ConnectingRodThickness */
}
};
@@ -180,6 +183,7 @@ InitRenderInfo(RenderInfo *render)
render->Texture = GL_FALSE;
render->DrawBox = GL_FALSE;
render->ShowInfo = GL_TRUE;
+ render->ShowBlock = GL_FALSE;
render->UseLists = GL_FALSE;
}
@@ -190,6 +194,9 @@ InitRenderInfo(RenderInfo *render)
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);
@@ -198,6 +205,7 @@ SetRenderState(RenderMode mode)
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:
@@ -214,6 +222,7 @@ SetRenderState(RenderMode mode)
glEnable(GL_TEXTURE_2D);
glEnable(GL_TEXTURE_GEN_S);
glEnable(GL_TEXTURE_GEN_T);
+ glLightModelfv(GL_LIGHT_MODEL_AMBIENT, gray4);
break;
default:
;
@@ -270,6 +279,19 @@ PistonShaftPosition(const Engine *eng, int piston)
/**
+ * 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
*/
@@ -518,6 +540,144 @@ DrawPositionedConnectingRod(const Engine *eng, float crankAngle)
/**
+ * 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
@@ -538,6 +698,11 @@ GenerateDisplayLists(Engine *eng)
glNewList(eng->PistonList, GL_COMPILE);
DrawPiston(eng);
glEndList();
+
+ eng->BlockList = glGenLists(1);
+ glNewList(eng->BlockList, GL_COMPILE);
+ DrawEngineBlock(eng);
+ glEndList();
}
@@ -553,10 +718,11 @@ FreeDisplayLists(Engine *eng)
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
@@ -602,10 +768,32 @@ DrawEngine(const Engine *eng, float crankAngle)
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();
}
@@ -745,9 +933,9 @@ Draw(void)
glPushMatrix();
glTranslatef(0, -0.75, 0);
- DrawEngine(Engines + CurEngine, Theta);
if (Render.DrawBox)
DrawBox();
+ DrawEngine(Engines + CurEngine, Theta);
glPopMatrix();
glPopMatrix();
@@ -900,6 +1088,12 @@ OptDisplayLists(void)
}
static void
+OptShowBlock(void)
+{
+ Render.ShowBlock = !Render.ShowBlock;
+}
+
+static void
OptShowInfo(void)
{
Render.ShowInfo = !Render.ShowInfo;
@@ -940,8 +1134,9 @@ static const MenuInfo MenuItems[] = {
{ "Change Engine", 'e', OptChangeEngine },
{ "Rendering Style", 'm', OptRenderMode },
{ "Display Lists", 'd', OptDisplayLists },
+ { "Show Block", 'b', OptShowBlock },
{ "Show Info", 'i', OptShowInfo },
- { "Show Box", 'b', OptShowBox },
+ { "Show Box", 'x', OptShowBox },
{ "Exit", 27, OptExit },
{ NULL, 'r', OptRotate },
{ NULL, 0, NULL }
@@ -1070,7 +1265,6 @@ Init(void)
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
glEnable(GL_NORMALIZE);
- glBlendFunc(GL_SRC_ALPHA, GL_ZERO);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
InitViewInfo(&View);
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-25 07:55:27 +0000