507 lines
16 KiB
C
507 lines
16 KiB
C
/******************************Module*Header*******************************\
|
|
* Module Name: gentex.c
|
|
*
|
|
* The Textured Flag style of the 3D Flying Objects screen saver.
|
|
*
|
|
* Texture maps .BMP files onto a simulation of a flag waving in the breeze.
|
|
*
|
|
* Copyright (c) 1994 Microsoft Corporation
|
|
*
|
|
\**************************************************************************/
|
|
|
|
#include <stdlib.h>
|
|
#include <windows.h>
|
|
#include <GL\gl.h>
|
|
#include <GL\glu.h>
|
|
#include <string.h>
|
|
#include <math.h>
|
|
#include "ss3dfo.h"
|
|
|
|
static float winTotalwidth = (float)0.75;
|
|
static float winTotalheight = (float)0.75 * (float)0.75;
|
|
|
|
#define MAX_FRAMES 20
|
|
|
|
// IPREC is the number of faces in the mesh that models the flag.
|
|
|
|
#define IPREC 15
|
|
|
|
static int Frames = 10;
|
|
static MESH winMesh[MAX_FRAMES];
|
|
static float sinAngle = (float)0.0;
|
|
static float xTrans = (float)0.0;
|
|
static int curMatl = 0;
|
|
|
|
// Material properties.
|
|
|
|
static RGBA matlBrightSpecular = {1.0f, 1.0f, 1.0f, 1.0f};
|
|
static RGBA matlDimSpecular = {0.5f, 0.5f, 0.5f, 1.0f};
|
|
static RGBA matlNoSpecular = {0.0f, 0.0f, 0.0f, 0.0f};
|
|
|
|
// Lighting properties.
|
|
|
|
static GLfloat light0Pos[] = {20.0f, 5.0f, 20.0f, 0.0f};
|
|
static GLfloat light1Pos[] = {-20.0f, 5.0f, 0.0f, 0.0f};
|
|
static RGBA light1Ambient = {0.0f, 0.0f, 0.0f, 0.0f};
|
|
static RGBA light1Diffuse = {0.4f, 0.4f, 0.4f, 1.0f};
|
|
static RGBA light1Specular = {0.0f, 0.0f, 0.0f, 0.0f};
|
|
|
|
static RGBA flagColors[] = {{1.0f, 1.0f, 1.0f, 1.0f},
|
|
{0.94f, 0.37f, 0.13f, 1.0f}, // red
|
|
};
|
|
|
|
// Default texture resource
|
|
|
|
static TEX_RES gTexRes = { TEX_BMP, IDB_DEFTEX };
|
|
|
|
static TEXTURE gTex = {0}; // One global texture
|
|
|
|
/******************************Public*Routine******************************\
|
|
* iPtInList
|
|
*
|
|
* Add a vertex and its normal to the mesh. If the vertex already exists,
|
|
* add in the normal to the existing normal (we to accumulate the average
|
|
* normal at each vertex). Normalization of the normals is the
|
|
* responsibility of the caller.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
static int iPtInList(MESH *mesh, int start,
|
|
POINT3D *p, POINT3D *norm, BOOL blend)
|
|
{
|
|
int i;
|
|
POINT3D *pts = mesh->pts + start;
|
|
|
|
if (blend) {
|
|
for (i = start; i < mesh->numPoints; i++, pts++) {
|
|
if ((pts->x == p->x) && (pts->y == p->y) && (pts->z == p->z)) {
|
|
mesh->norms[i].x += norm->x;
|
|
mesh->norms[i].y += norm->y;
|
|
mesh->norms[i].z += norm->z;
|
|
return i;
|
|
}
|
|
}
|
|
} else {
|
|
i = mesh->numPoints;
|
|
}
|
|
|
|
mesh->pts[i] = *p;
|
|
mesh->norms[i] = *norm;
|
|
mesh->numPoints++;
|
|
return i;
|
|
}
|
|
|
|
/******************************Public*Routine******************************\
|
|
* getZpos
|
|
*
|
|
* Get the z-position (depth) of the "wavy" flag component at the given x.
|
|
*
|
|
* The function used to model the wave is:
|
|
*
|
|
* 1/2
|
|
* z = x * sin((2*PI*x + sinAngle) / 4)
|
|
*
|
|
* The shape of the wave varies from frame to frame by changing the
|
|
* phase, sinAngle.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
float getZpos(float x)
|
|
{
|
|
float xAbs = x - xTrans;
|
|
float angle = sinAngle + ((float) (2.0 * PI) * (xAbs / winTotalwidth));
|
|
|
|
xAbs = winTotalwidth - xAbs;
|
|
// xAbs += (winTotalwidth / 2.0);
|
|
|
|
return (float)((sin((double)angle) / 4.0) *
|
|
sqrt((double)(xAbs / winTotalwidth )));
|
|
}
|
|
|
|
/******************************Public*Routine******************************\
|
|
* genTex
|
|
*
|
|
* Generate a mesh representing a frame of the flag. The phase, sinAngle,
|
|
* is a global variable.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
void genTex(MESH *winMesh)
|
|
{
|
|
POINT3D pos;
|
|
POINT3D pts[4];
|
|
float w, h;
|
|
int i;
|
|
|
|
newMesh(winMesh, IPREC * IPREC, IPREC * IPREC);
|
|
|
|
// Width and height of each face
|
|
|
|
w = (winTotalwidth) / (float)(IPREC + 1);
|
|
h = winTotalheight;
|
|
|
|
// Generate the mesh data. At equally spaced intervals along the x-axis,
|
|
// we compute the z-position of the flag surface.
|
|
|
|
pos.y = (float) 0.0;
|
|
pos.z = (float) 0.0;
|
|
|
|
for (i = 0, pos.x = xTrans; i < IPREC; i++, pos.x += w) {
|
|
int faceCount = winMesh->numFaces;
|
|
|
|
pts[0].x = (float)pos.x;
|
|
pts[0].y = (float)(pos.y);
|
|
pts[0].z = getZpos(pos.x);
|
|
|
|
pts[1].x = (float)pos.x;
|
|
pts[1].y = (float)(pos.y + h);
|
|
pts[1].z = getZpos(pos.x);
|
|
|
|
pts[2].x = (float)(pos.x + w);
|
|
pts[2].y = (float)(pos.y);
|
|
pts[2].z = getZpos(pos.x + w);
|
|
|
|
pts[3].x = (float)(pos.x + w);
|
|
pts[3].y = (float)(pos.y + h);
|
|
pts[3].z = getZpos(pos.x + w);
|
|
|
|
// Compute the face normal.
|
|
|
|
ss_calcNorm(&winMesh->faces[faceCount].norm, pts + 2, pts + 1, pts);
|
|
|
|
// Add the face to the mesh.
|
|
|
|
winMesh->faces[faceCount].material = 0;
|
|
winMesh->faces[faceCount].p[0] = iPtInList(winMesh, 0, pts,
|
|
&winMesh->faces[faceCount].norm, TRUE);
|
|
winMesh->faces[faceCount].p[1] = iPtInList(winMesh, 0, pts + 1,
|
|
&winMesh->faces[faceCount].norm, TRUE);
|
|
winMesh->faces[faceCount].p[2] = iPtInList(winMesh, 0, pts + 2,
|
|
&winMesh->faces[faceCount].norm, TRUE);
|
|
winMesh->faces[faceCount].p[3] = iPtInList(winMesh, 0, pts + 3,
|
|
&winMesh->faces[faceCount].norm, TRUE);
|
|
|
|
winMesh->numFaces++;
|
|
}
|
|
|
|
// Normalize the vertex normals in the mesh.
|
|
|
|
ss_normalizeNorms(winMesh->norms, winMesh->numPoints);
|
|
}
|
|
|
|
/******************************Public*Routine******************************\
|
|
* initTexScene
|
|
*
|
|
* Initialize the screen saver.
|
|
*
|
|
* This function is exported to the main module in ss3dfo.c.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
void initTexScene()
|
|
{
|
|
int i;
|
|
float angleDelta;
|
|
float aspectRatio;
|
|
|
|
// Initialize the transform.
|
|
|
|
glMatrixMode(GL_PROJECTION);
|
|
glLoadIdentity();
|
|
glOrtho(-0.25, 1.0, -0.25, 1.0, 0.0, 3.0);
|
|
glTranslatef(0.0f, 0.0f, -1.5f);
|
|
|
|
// Initialize and turn on lighting.
|
|
|
|
glLightfv(GL_LIGHT0, GL_POSITION, light0Pos);
|
|
|
|
glLightfv(GL_LIGHT1, GL_AMBIENT, (GLfloat *) &light1Ambient);
|
|
glLightfv(GL_LIGHT1, GL_DIFFUSE, (GLfloat *) &light1Diffuse);
|
|
glLightfv(GL_LIGHT1, GL_SPECULAR, (GLfloat *) &light1Specular);
|
|
glLightfv(GL_LIGHT1, GL_POSITION, light1Pos);
|
|
glEnable(GL_LIGHT1);
|
|
glDisable(GL_DEPTH_TEST);
|
|
|
|
// Leave OpenGL in a state ready to accept the model view transform (we
|
|
// are going to have the flag vary its orientation from frame to frame).
|
|
|
|
glMatrixMode(GL_MODELVIEW);
|
|
|
|
// Define orientation of polygon faces.
|
|
|
|
glFrontFace(GL_CW);
|
|
// glEnable(GL_CULL_FACE);
|
|
|
|
Frames = (int)((float)(MAX_FRAMES / 2) * fTesselFact);
|
|
|
|
// Load user texture - if that fails load default texture resource
|
|
|
|
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
|
|
if( ss_LoadTextureFile( &gTexFile, &gTex ) ||
|
|
ss_LoadTextureResource( &gTexRes, &gTex) )
|
|
{
|
|
glEnable(GL_TEXTURE_2D);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
|
|
glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
|
|
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
|
|
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
|
|
|
|
ss_SetTexture( &gTex );
|
|
|
|
// Correct aspect ratio of flag to match image.
|
|
//
|
|
// The 1.4 is a correction factor to account for the length of the
|
|
// curve that models the surface ripple of the waving flag. This
|
|
// factor is the length of the curve at zero phase. It would be
|
|
// more accurate to determine the length of the curve at each phase,
|
|
// but this is a sufficient approximation for our purposes.
|
|
|
|
aspectRatio = ((float) gTex.height / (float) gTex.width)
|
|
* (float) 1.4;
|
|
|
|
if (aspectRatio < (float) 1.0) {
|
|
winTotalwidth = (float)0.75;
|
|
winTotalheight = winTotalwidth * aspectRatio;
|
|
} else {
|
|
winTotalheight = (float) 0.75;
|
|
winTotalwidth = winTotalheight / aspectRatio;
|
|
};
|
|
}
|
|
|
|
if (Frames < 5)
|
|
Frames = 5;
|
|
if (Frames > MAX_FRAMES)
|
|
Frames = MAX_FRAMES;
|
|
|
|
// Generate the geometry data (stored in the array of mesh structures),
|
|
// for each frame of the animation. The shape of the flag is varied by
|
|
// changing the global variable sinAngle.
|
|
|
|
angleDelta = (float)(2.0 * PI) / (float)Frames;
|
|
sinAngle = (float) 0.0;
|
|
|
|
for (i = 0; i < Frames; i++) {
|
|
genTex(&winMesh[i]);
|
|
sinAngle += angleDelta;
|
|
}
|
|
}
|
|
|
|
/******************************Public*Routine******************************\
|
|
* delTexScene
|
|
*
|
|
* Cleanup the data associated with this screen saver.
|
|
*
|
|
* This function is exported to the main module in ss3dfo.c.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
void delTexScene()
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < Frames; i++)
|
|
delMesh(&winMesh[i]);
|
|
|
|
// Delete the texture
|
|
ss_DeleteTexture( &gTex );
|
|
}
|
|
|
|
/******************************Public*Routine******************************\
|
|
* updateTexScene
|
|
*
|
|
* Generate a scene by taking one of the meshes and rendering it with
|
|
* OpenGL.
|
|
*
|
|
* This function is exported to the main module in ss3dfo.c.
|
|
*
|
|
\**************************************************************************/
|
|
|
|
void updateTexScene(int flags)
|
|
{
|
|
MESH *mesh;
|
|
MFACE *faces;
|
|
int i;
|
|
static double mxrot = 23.0;
|
|
static double myrot = 23.0;
|
|
static double mzrot = 5.7;
|
|
static double mxrotInc = 0.0;
|
|
static double myrotInc = 3.0;
|
|
static double mzrotInc = 0.0;
|
|
static int h = 0;
|
|
static int frameNum = 0;
|
|
POINT3D *pp;
|
|
POINT3D *pn;
|
|
int lastC, lastD;
|
|
int aOffs, bOffs, cOffs, dOffs;
|
|
int a, b;
|
|
GLfloat s = (GLfloat) 0.0;
|
|
GLfloat ds;
|
|
|
|
// In addition to having the flag wave (an effect acheived by switching
|
|
// meshes from frame to frame), the flag changes its orientation from
|
|
// frame to frame. This is done by applying a model view transform.
|
|
|
|
glLoadIdentity();
|
|
glRotatef((float)mxrot, 1.0f, 0.0f, 0.0f);
|
|
glRotatef((float)myrot, 0.0f, 1.0f, 0.0f);
|
|
glRotatef((float)mzrot, 0.0f, 0.0f, 1.0f);
|
|
|
|
// Divide the texture into IPREC slices. ds is the texture coordinate
|
|
// delta we apply as we move along the x-axis.
|
|
|
|
ds = (GLfloat)1.0 / (GLfloat)IPREC;
|
|
|
|
// Setup the material property of the flag. The material property, light
|
|
// properties, and polygon orientation will interact with the texture.
|
|
|
|
curMatl = 0;
|
|
// glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE, &flagColors[0]);
|
|
// glMaterialfv(GL_FRONT, GL_SPECULAR, &matlBrightSpecular);
|
|
// glMaterialf(GL_FRONT, GL_SHININESS, 60.0);
|
|
glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, (GLfloat *) &flagColors[0]);
|
|
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, (GLfloat *) &matlBrightSpecular);
|
|
glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, (float) 60.0);
|
|
|
|
// Pick the mesh for the current frame.
|
|
|
|
mesh = &winMesh[frameNum];
|
|
|
|
// Take the geometry data is the mesh and convert it to a single OpenGL
|
|
// quad strip. If smooth shading is required, use the vertex normals stored
|
|
// in the mesh. Otherwise, use the face normals.
|
|
//
|
|
// As we define each vertex, we also define a corresponding vertex and
|
|
// texture coordinate.
|
|
|
|
glBegin(GL_QUAD_STRIP);
|
|
|
|
pp = mesh->pts;
|
|
pn = mesh->norms;
|
|
|
|
for (i = 0, faces = mesh->faces, lastC = faces->p[0], lastD = faces->p[1];
|
|
i < mesh->numFaces; i++, faces++) {
|
|
|
|
a = faces->p[0];
|
|
b = faces->p[1];
|
|
|
|
if (!bSmoothShading) {
|
|
// Since flag is a single quad strip, this isn't needed.
|
|
// But lets keep it in case we ever change to a more
|
|
// complex model (ie., one that uses more than one quad
|
|
// strip).
|
|
#if 0
|
|
if ((a != lastC) || (b != lastD)) {
|
|
glNormal3fv((GLfloat *)&(faces - 1)->norm);
|
|
|
|
glTexCoord2f(s, (float) 0.0);
|
|
glVertex3fv((GLfloat *)((char *)pp +
|
|
(lastC << 3) + (lastC << 2)));
|
|
glTexCoord2f(s, (float) 1.0);
|
|
glVertex3fv((GLfloat *)((char *)pp +
|
|
(lastD << 3) + (lastD << 2)));
|
|
s += ds;
|
|
glEnd();
|
|
glBegin(GL_QUAD_STRIP);
|
|
}
|
|
#endif
|
|
|
|
if (faces->material != curMatl) {
|
|
curMatl = faces->material;
|
|
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR,
|
|
(GLfloat *) &matlNoSpecular);
|
|
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE,
|
|
(GLfloat *) &flagColors[curMatl]);
|
|
}
|
|
|
|
glNormal3fv((GLfloat *)&faces->norm);
|
|
glTexCoord2f(s, (float) 0.0);
|
|
glVertex3fv((GLfloat *)((char *)pp + (a << 3) + (a << 2)));
|
|
glTexCoord2f(s, (float) 1.0);
|
|
glVertex3fv((GLfloat *)((char *)pp + (b << 3) + (b << 2)));
|
|
s += ds;
|
|
} else {
|
|
// Since flag is a single quad strip, this isn't needed.
|
|
// But lets keep it in case we ever change to a more
|
|
// complex model (ie., one that uses more than one quad
|
|
// strip).
|
|
#if 0
|
|
if ((a != lastC) || (b != lastD)) {
|
|
cOffs = (lastC << 3) + (lastC << 2);
|
|
dOffs = (lastD << 3) + (lastD << 2);
|
|
|
|
glTexCoord2f(s, (float) 0.0);
|
|
glNormal3fv((GLfloat *)((char *)pn + cOffs));
|
|
glVertex3fv((GLfloat *)((char *)pp + cOffs));
|
|
glTexCoord2f(s, (float) 1.0);
|
|
glNormal3fv((GLfloat *)((char *)pn + dOffs));
|
|
glVertex3fv((GLfloat *)((char *)pp + dOffs));
|
|
s += ds;
|
|
glEnd();
|
|
glBegin(GL_QUAD_STRIP);
|
|
}
|
|
#endif
|
|
|
|
aOffs = (a << 3) + (a << 2);
|
|
bOffs = (b << 3) + (b << 2);
|
|
|
|
if (faces->material != curMatl) {
|
|
curMatl = faces->material;
|
|
glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR,
|
|
(GLfloat *) &matlNoSpecular);
|
|
glMaterialfv(GL_FRONT, GL_AMBIENT_AND_DIFFUSE,
|
|
(GLfloat *) &flagColors[curMatl]);
|
|
}
|
|
|
|
glTexCoord2f(s, (float) 0.0);
|
|
glNormal3fv((GLfloat *)((char *)pn + aOffs));
|
|
glVertex3fv((GLfloat *)((char *)pp + aOffs));
|
|
glTexCoord2f(s, (float) 1.0);
|
|
glNormal3fv((GLfloat *)((char *)pn + bOffs));
|
|
glVertex3fv((GLfloat *)((char *)pp + bOffs));
|
|
s += ds;
|
|
}
|
|
|
|
lastC = faces->p[2];
|
|
lastD = faces->p[3];
|
|
}
|
|
|
|
if (!bSmoothShading) {
|
|
glNormal3fv((GLfloat *)&(faces - 1)->norm);
|
|
glTexCoord2f(s, (float) 0.0);
|
|
glVertex3fv((GLfloat *)((char *)pp + (lastC << 3) + (lastC << 2)));
|
|
glTexCoord2f(s, (float) 1.0);
|
|
glVertex3fv((GLfloat *)((char *)pp + (lastD << 3) + (lastD << 2)));
|
|
} else {
|
|
cOffs = (lastC << 3) + (lastC << 2);
|
|
dOffs = (lastD << 3) + (lastD << 2);
|
|
|
|
glTexCoord2f(s, (float) 0.0);
|
|
glNormal3fv((GLfloat *)((char *)pn + cOffs));
|
|
glVertex3fv((GLfloat *)((char *)pp + cOffs));
|
|
glTexCoord2f(s, (float) 1.0);
|
|
glNormal3fv((GLfloat *)((char *)pn + dOffs));
|
|
glVertex3fv((GLfloat *)((char *)pp + dOffs));
|
|
}
|
|
|
|
glEnd();
|
|
|
|
// Transfer the image to the floating OpenGL window.
|
|
|
|
// Determine the flag orientation for the next frame.
|
|
// What we are doing is an oscillating rotation about the y-axis
|
|
// (mxrotInc and mzrotInc are currently 0).
|
|
|
|
mxrot += mxrotInc;
|
|
myrot += myrotInc;
|
|
mzrot += mzrotInc;
|
|
|
|
if ((myrot < -65.0) || (myrot > 25.0))
|
|
myrotInc = -myrotInc;
|
|
|
|
frameNum++;
|
|
if (frameNum >= Frames)
|
|
frameNum = 0;
|
|
}
|