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authorKeith Whitwell <keith@tungstengraphics.com>2003-02-23 21:04:38 +0000
committerKeith Whitwell <keith@tungstengraphics.com>2003-02-23 21:04:38 +0000
commit2b3cd8510793ed01a85466d8064837608f1c9bcb (patch)
treef0d2b28a2b5c85fe0d1c135614b01b42805ee93d /progs
parent12acb24b608fdb4f01d5cf4aaf68344fade7581d (diff)
Subset terrain
Diffstat (limited to 'progs')
-rw-r--r--progs/demos/terrain.c167
1 files changed, 139 insertions, 28 deletions
diff --git a/progs/demos/terrain.c b/progs/demos/terrain.c
index 9063c939d5e..f389f54cd68 100644
--- a/progs/demos/terrain.c
+++ b/progs/demos/terrain.c
@@ -51,7 +51,7 @@ static GLfloat terraincolor[256 * 256][3];
static int win = 0;
-static int fog = 1;
+static int fog = 0;
static int bfcull = 1;
static int usetex = 1;
static int poutline = 0;
@@ -105,6 +105,21 @@ calcposobs(void)
obs[1] = 0.0;
}
+static void
+perspective(GLdouble fovy, GLdouble aspect, GLdouble zNear, GLdouble zFar)
+{
+ GLdouble xmin, xmax, ymin, ymax;
+
+ ymax = zNear * tan(fovy * M_PI / 360.0);
+ ymin = -ymax;
+ xmin = ymin * aspect;
+ xmax = ymax * aspect;
+
+ /* don't call glFrustum() because of error semantics (covglu) */
+ glFrustum(xmin, xmax, ymin, ymax, zNear, zFar);
+}
+
+
static void
reshape(int width, int height)
{
@@ -113,7 +128,7 @@ reshape(int width, int height)
glViewport(0, 0, (GLint) width, (GLint) height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
- gluPerspective(50.0, ((GLfloat) width / (GLfloat) height),
+ perspective(50.0, ((GLfloat) width / (GLfloat) height),
lenghtXmnt * stepYmnt * 0.01, lenghtXmnt * stepYmnt * 0.7);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
@@ -209,13 +224,25 @@ printstring(void *font, char *string)
glutBitmapCharacter(font, string[i]);
}
+
+
+static void _subset_Rectf( GLfloat x1, GLfloat y1, GLfloat x2, GLfloat y2 )
+{
+ glBegin( GL_QUADS );
+ glVertex2f( x1, y1 );
+ glVertex2f( x2, y1 );
+ glVertex2f( x2, y2 );
+ glVertex2f( x1, y2 );
+ glEnd();
+}
+
static void
printhelp(void)
{
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glColor4f(0.0, 0.0, 0.0, 0.5);
- glRecti(40, 40, 600, 440);
+ _subset_Rectf(40, 40, 600, 440);
glDisable(GL_BLEND);
glColor3f(1.0, 0.0, 0.0);
@@ -351,6 +378,87 @@ dojoy(void)
#endif
}
+static void
+lookAt(GLfloat eyex, GLfloat eyey, GLfloat eyez,
+ GLfloat centerx, GLfloat centery, GLfloat centerz,
+ GLfloat upx, GLfloat upy, GLfloat upz)
+{
+ GLfloat m[16];
+ GLfloat x[3], y[3], z[3];
+ GLfloat mag;
+
+ /* Make rotation matrix */
+
+ /* Z vector */
+ z[0] = eyex - centerx;
+ z[1] = eyey - centery;
+ z[2] = eyez - centerz;
+ mag = sqrt(z[0] * z[0] + z[1] * z[1] + z[2] * z[2]);
+ if (mag) { /* mpichler, 19950515 */
+ z[0] /= mag;
+ z[1] /= mag;
+ z[2] /= mag;
+ }
+
+ /* Y vector */
+ y[0] = upx;
+ y[1] = upy;
+ y[2] = upz;
+
+ /* X vector = Y cross Z */
+ x[0] = y[1] * z[2] - y[2] * z[1];
+ x[1] = -y[0] * z[2] + y[2] * z[0];
+ x[2] = y[0] * z[1] - y[1] * z[0];
+
+ /* Recompute Y = Z cross X */
+ y[0] = z[1] * x[2] - z[2] * x[1];
+ y[1] = -z[0] * x[2] + z[2] * x[0];
+ y[2] = z[0] * x[1] - z[1] * x[0];
+
+ /* mpichler, 19950515 */
+ /* cross product gives area of parallelogram, which is < 1.0 for
+ * non-perpendicular unit-length vectors; so normalize x, y here
+ */
+
+ mag = sqrt(x[0] * x[0] + x[1] * x[1] + x[2] * x[2]);
+ if (mag) {
+ x[0] /= mag;
+ x[1] /= mag;
+ x[2] /= mag;
+ }
+
+ mag = sqrt(y[0] * y[0] + y[1] * y[1] + y[2] * y[2]);
+ if (mag) {
+ y[0] /= mag;
+ y[1] /= mag;
+ y[2] /= mag;
+ }
+
+#define M(row,col) m[col*4+row]
+ M(0, 0) = x[0];
+ M(0, 1) = x[1];
+ M(0, 2) = x[2];
+ M(0, 3) = 0.0;
+ M(1, 0) = y[0];
+ M(1, 1) = y[1];
+ M(1, 2) = y[2];
+ M(1, 3) = 0.0;
+ M(2, 0) = z[0];
+ M(2, 1) = z[1];
+ M(2, 2) = z[2];
+ M(2, 3) = 0.0;
+ M(3, 0) = 0.0;
+ M(3, 1) = 0.0;
+ M(3, 2) = 0.0;
+ M(3, 3) = 1.0;
+#undef M
+ glMultMatrixf(m);
+
+ /* Translate Eye to Origin */
+ glTranslatef(-eyex, -eyey, -eyez);
+
+}
+
static void
drawscene(void)
{
@@ -359,24 +467,24 @@ drawscene(void)
dojoy();
glShadeModel(GL_SMOOTH);
- glEnable(GL_DEPTH_TEST);
+/* glEnable(GL_DEPTH_TEST); */
if (usetex)
glEnable(GL_TEXTURE_2D);
else
glDisable(GL_TEXTURE_2D);
- if (fog)
- glEnable(GL_FOG);
- else
- glDisable(GL_FOG);
+/* if (fog) */
+/* glEnable(GL_FOG); */
+/* else */
+/* glDisable(GL_FOG); */
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
calcposobs();
- gluLookAt(obs[0], obs[1], obs[2],
+ lookAt(obs[0], obs[1], obs[2],
obs[0] + dir[0], obs[1] + dir[1], obs[2] + dir[2],
0.0, 1.0, 0.0);
@@ -384,8 +492,8 @@ drawscene(void)
glPopMatrix();
glDisable(GL_TEXTURE_2D);
- glDisable(GL_DEPTH_TEST);
- glDisable(GL_FOG);
+/* glDisable(GL_DEPTH_TEST); */
+/* glDisable(GL_FOG); */
glShadeModel(GL_FLAT);
glMatrixMode(GL_PROJECTION);
@@ -549,7 +657,7 @@ calccolor(GLfloat height, GLfloat c[3])
static void
loadpic(void)
{
- GLubyte bufferter[256 * 256], terrainpic[256 * 256];
+ GLubyte bufferter[256 * 256], terrainpic[256 * 256][4];
FILE *FilePic;
int i, tmp;
GLenum gluerr;
@@ -565,25 +673,28 @@ loadpic(void)
terrain[i] = (bufferter[i] * (heightMnt / 255.0f));
calccolor((GLfloat) bufferter[i], terraincolor[i]);
tmp = (((int) bufferter[i]) + 96);
- terrainpic[i] = (tmp > 255) ? 255 : tmp;
+ terrainpic[i][0] = (tmp > 255) ? 255 : tmp;
+ terrainpic[i][1] = (tmp > 255) ? 255 : tmp;
+ terrainpic[i][2] = (tmp > 255) ? 255 : tmp;
+ terrainpic[i][0] = 255;
}
glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
- if ((gluerr = gluBuild2DMipmaps(GL_TEXTURE_2D, 1, 256, 256, GL_LUMINANCE,
+ if ((gluerr = gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGBA, 256, 256, GL_RGBA,
GL_UNSIGNED_BYTE,
- (GLvoid *) (&terrainpic[0])))) {
+ (GLvoid *) (&terrainpic[0][0])))) {
fprintf(stderr, "GLULib%s\n", (char *) gluErrorString(gluerr));
exit(-1);
}
- glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
- glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
- glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
GL_LINEAR_MIPMAP_LINEAR);
- glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+ glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
- glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+ glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
glEnable(GL_TEXTURE_2D);
}
@@ -593,21 +704,21 @@ init(void)
float fogcolor[4] = { 0.6, 0.7, 0.7, 1.0 };
glClearColor(fogcolor[0], fogcolor[1], fogcolor[2], fogcolor[3]);
- glClearDepth(1.0);
- glDepthFunc(GL_LEQUAL);
+/* glClearDepth(1.0); */
+/* glDepthFunc(GL_LEQUAL); */
glShadeModel(GL_SMOOTH);
- glEnable(GL_DEPTH_TEST);
+/* glEnable(GL_DEPTH_TEST); */
glEnable(GL_CULL_FACE);
glDisable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
- glEnable(GL_FOG);
- glFogi(GL_FOG_MODE, GL_EXP2);
- glFogfv(GL_FOG_COLOR, fogcolor);
- glFogf(GL_FOG_DENSITY, 0.0007);
+/* glEnable(GL_FOG); */
+/* glFogi(GL_FOG_MODE, GL_EXP2); */
+/* glFogfv(GL_FOG_COLOR, fogcolor); */
+/* glFogf(GL_FOG_DENSITY, 0.0007); */
#ifdef FX
- glHint(GL_FOG_HINT, GL_NICEST);
+/* glHint(GL_FOG_HINT, GL_NICEST); */
#endif
reshape(scrwidth, scrheight);