PSP gu library. Drawing Lines

[BlackDragon777]

So where can I read the documentation on the gu library. Also how to I draw lines using the hardware. Are there some tutorials? I checked out the Lines smaple in the pspsdk however I didn't quite follow it. I don't know exactly what all the commands do. Can someone point me in the right direction please? Thanks!


GOD Bless you Always!!!!

[BlackDragon777]

Also when I say I want to draw lines using the hardware, I mean I want to do it similar to the way you do it on a PS2. I don't want to use software by using a function that plots pixels on a line. I want to send a simple graphics packet to the gs in the PSP and have it draw the line for me. Any ideas where I can get more info on this? Thanks!

[BlackDragon777]

Nevermind. I got it now. Thanks anyways though!

[BlackDragon777]

Well I can draw triangles. However I can't seem to draw lines afterall.

This is how I setup my code for drawing lines.

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Points = (point2D *)sceGuGetMemory(sizeof(point2D)*2);

Points[0].x = 10;
Points[0].y = 11;
Points[1].x = 100;
Points[1].y = 110;

sceGuDrawArray(GU_LINES, GU_VERTEX_32BITF | GU_TRANSFORM_2D, 2, 0, Points);

However I don't see a line on the screen. Is there something wrong with the way I arrange my points in memory? Thanks!

[chp]

Even though you bypass the transform, you need to specify a Z-component. So I hope your structure looks like this:

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typedef struct
{
  float x,y,z;
} point2D;

Otherwise it'll read the vertices improperly.

[ector]

Also, remember to flush the cache or to "uncache" the pointer.. or does sceGuGetMemory do that nowadays?

[chp]

sceGuGetMemory() has always "uncached" the pointer. Users just keep forgetting it when they aren't using that function. :)

[BlackDragon777]

Well just for reference incase anyone else encounters my same problem,

my point2D structure looked like so,

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typedef struct
{
    int x,y;

} point2D;

When in actuality, like chp suggested, it should look like so,

Code: Select all

typedef struct
{
    float x,y,z;

} point2D;

Thanks for all the help everyone!