Variables Getting Overwritten?

TheChuckster · 2004-04-14T00:51:41

Hello. I have the following header: #ifndef PRIMITIVES_H_ #define PRIMITIVES_H_ #include <gl\gl.h> #include <gl\glu.h> #include <gl\glaux.h> typedef struct Vertex { float x; float y; float z; } Vertex; typedef struct Face { Vertex Vertices[3]; } Face; typedef struct RGBColor { float r; float g; float b; } RGBColor; typedef struct Quad { RGBColor QuadColor; Vertex Vertices[4]; } Quad; struct BoxPrimitive { Quad Quads[6]; RGBColor Color; Vertex Position; Vertex Rotation; short ClassID; BoxPrimitive *nextaddr; void render(void); void SetColor(float r, float g, float b); void SetPosition(float x, float y, float z); void SetRotation(float x, float y, float z); void Translate(float x, float y, float z); void Rotate(float x, float y, float z); }; int CreateBox(float LengthX, float LengthY, float LengthZ); void RenderAllBoxes(); extern BoxPrimitive *list; #endif // PRIMITIVES_H_ Basically, it''s a fancy way of drawing and manipulating boxes. Any how, BoxPrimitive is a linked list and the points of the cubes are calculated the CreateBox function and stored in Quads which in turn are stored in Vertices. However, void BoxPrimitive::SetColor(float r, float g, float b) { // Convert to 0-1 instead of 0-255 r = r / 255; g = g / 255; b = b / 255; Color.r = r; Color.g = g; Color.b = b; return; } is a function that sets the color. When I call this function, some how the values stored in the points become overwritten and the cube appears extremely distorted on the screen. I have been seeking the answer to this problem for days, considering this is my first attempt at C++ programming. Please help me.

NeHe Productions Affiliates

Started by TheChuckster April 13, 2004 08:05 AM

11 comments, last by TheChuckster 20 years ago

TheChuckster

130

Author

April 13, 2004 06:29 PM

Problem solved. By making Rotation and Position private, it's fine. But I never attempt to change it outside of SetRotation, SetPosition, Rotate, and Translate. Weird...

[edited by - TheChuckster on April 13, 2004 8:40:46 PM]

---2x John Carmack

cowsarenotevil

3,015

April 14, 2004 12:18 AM

quote:Original post by TheChuckster
Problem solved. By making Rotation and Position private, it''s fine. But I never attempt to change it outside of SetRotation, SetPosition, Rotate, and Translate. Weird...

[edited by - TheChuckster on April 13, 2004 8:40:46 PM]

I didn''t really pay attentian to what''s going on, but is there a chance you had a pointer/array in some other file that wrote to the wrong location?

<-- that''s still a link if you didn''t notice
"Gay marriage will encourage people to be gay, in the same way that hanging around tall people will make you tall." - Grizwald

-~-The Cow of Darkness-~-

AndyL

122

April 14, 2004 12:49 AM

quote:Original post by TheChuckster

for (i = 1; i <= 6; i++)
{
for(j = 1; j <= 4; j++)
{

Here's your problem.

You're counting starting with 1. Arrays are numbered starting with zero.

So in these for() loops you're skipping the first element of the arrays, and worse than that, you're writing data after the array ends which could be over-writing who knows what. (Probably whatever you declared next.)

Those lines should read :

quote:for (i = 0; i < 6; i++)
{
for(j = 0; j < 4; j++)
{

Hope this helps!

-Andy

[edited by - AndyL on April 14, 2004 1:51:41 AM]

Variables Getting Overwritten?

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Variables Getting Overwritten?

This topic is closed to new replies.

Popular Topics

Recommended Tutorials

Reticulating splines