Precompile snowflakes in display list.

3 files changed, 39 insertions, 24 deletions

diff --git a/snowflake.c b/snowflake.c
index 76ae798..7155bc2 100644
--- a/snowflake.c
+++ b/snowflake.c
@@ -85,19 +85,6 @@ static const float N0035[3] = {0.390179, -0.892727, 0.225257};
 
 void DrawSnowflake(int wire) {
 
-glRotatef(180.0, 0.0, 1.0, 0.0);
-glRotatef(90.0, 0.0, 1.0, 0.0);
-glEnable(GL_CULL_FACE);
-glEnable(GL_DEPTH_TEST);
-glDisable(GL_NORMALIZE);
-
-
-glDisable (GL_COLOR_MATERIAL);
-glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
-glMaterialfv (GL_FRONT_AND_BACK, GL_SHININESS, null_shininess);
-glMaterialfv (GL_FRONT_AND_BACK, GL_AMBIENT, null_ambient);
-glMaterialfv (GL_FRONT_AND_BACK, GL_DIFFUSE, null_diffuse);
-glMaterialfv (GL_FRONT_AND_BACK, GL_SPECULAR, null_specular);
 GLenum capQuads = wire ? GL_LINE_LOOP : GL_QUADS;
 glBegin(capQuads);
 glNormal3fv(N0000);
@@ -371,7 +358,23 @@ glVertex3fv(P0028);
 glNormal3fv(N0031);
 glVertex3fv(P0031);
 glEnd ();
+}
 
-glDisable(GL_CULL_FACE);
+void initDrawSnowflake() {
+glRotatef(180.0, 0.0, 1.0, 0.0);
+glRotatef(90.0, 0.0, 1.0, 0.0);
+glEnable(GL_CULL_FACE);
+glEnable(GL_DEPTH_TEST);
+glEnable(GL_RESCALE_NORMAL);
+
+glDisable (GL_COLOR_MATERIAL);
+glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
+glMaterialfv (GL_FRONT_AND_BACK, GL_SHININESS, null_shininess);
+glMaterialfv (GL_FRONT_AND_BACK, GL_AMBIENT, null_ambient);
+glMaterialfv (GL_FRONT_AND_BACK, GL_DIFFUSE, null_diffuse);
+glMaterialfv (GL_FRONT_AND_BACK, GL_SPECULAR, null_specular);
 }
 
+void finDrawSnowflake() {
+glDisable(GL_CULL_FACE);
+}
diff --git a/snowglobe-internal.h b/snowglobe-internal.h
index 13bcf92..5538a13 100644
--- a/snowglobe-internal.h
+++ b/snowglobe-internal.h
@@ -142,7 +142,11 @@ void SnowflakeDrift (SnowglobeScreen *, int);
 void initializeWorldVariables(int, float);
 void updateSpeedFactor(float);
 void RenderWater(int, float, Bool, Bool);
+
 void DrawSnowflake (int);
+void initDrawSnowflake(void);
+void finDrawSnowflake(void);
+
 void DrawSnowman (int);
 
 //utility methods
@@ -153,7 +157,8 @@ float symmDistr(void); //symmetric distribution
 
 //maybe define a struct for these values
 float speedFactor; // global variable (fish/crab speeds multiplied by this value)
-float radius;//radius on which the hSize points lie (corners for odd #, midpoints for even #)
+float radius;//radius on which the hSize points lie
+float distance;//perpendicular distance to wall from centre
 float waterHeight; //water surface height
 int waveGridSize;
 float waveAmplitude;
@@ -162,16 +167,16 @@ float smallWaveAmplitude;
 float smallWaveFrequency;
 Bool renderGround;
 
-//All calculations that matter with angles are done clockwise.
-//I think of it as x=radius, y=0 being directed from the cetnre towards the 1st desktop
+GLuint snowflakeDisplayList;
+
+
+//All calculations that matter with angles are done clockwise from top.
+//I think of it as x=radius, y=0 being the top (towards 1st desktop from above view)
 //and the z coordinate as height.
 
-//NOTE - might scrap *th if it is not used.
 
-float *invTanTh; // 1/tanf(th[index]) - used in calculating perp. distance to wall
 int hSize; // horizontal desktop size
 float q;   // equal to float version of hSize (replace with hSizef some time)
-float distance;
 
 
 #endif
diff --git a/snowglobe.c b/snowglobe.c
index 4730161..51282be 100644
--- a/snowglobe.c
+++ b/snowglobe.c
@@ -116,9 +116,12 @@ initSnowglobe (CompScreen *s)
 
 	waterHeight = 50000;
 
-
 	speedFactor = snowglobeGetSpeedFactor(s);
-
+	
+	snowflakeDisplayList = glGenLists(1);
+	glNewList(snowflakeDisplayList, GL_COMPILE);
+	DrawSnowflake(0);
+	glEndList();
 }
 
 void initializeWorldVariables(int hs, float perpDistCentreToWall) { //precalculate some values
@@ -140,6 +143,8 @@ freeSnowglobe (CompScreen *s)
 
 	freeWater (as->water);
 	freeWater (as->ground);
+	
+	glDeleteLists(snowflakeDisplayList,  1);
 }
 
 static void
@@ -272,7 +277,7 @@ static void snowglobePaintInside (CompScreen *s,
 	glEnable (GL_COLOR_MATERIAL);
 
 	glTexEnvi (GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
-
+	
 	for (i = 0; i < as->numSnowflakes; i++)
 	{
 		glPushMatrix();
@@ -281,7 +286,9 @@ static void snowglobePaintInside (CompScreen *s,
 		float scale = 0.01*as->snow[i].size;
 		glScalef (scale, scale, scale);
 
-		DrawSnowflake(0);
+		initDrawSnowflake();
+		glCallList(snowflakeDisplayList);
+		finDrawSnowflake();
 		glPopMatrix();
 	}