sceGumRotateX problem

sigutis · Post by **sigutis** » Thu Mar 26, 2009 7:32 pm

Hello, I am trying to rotate an image like this

        vertices&#91;0&#93;.u = minx; 
	vertices&#91;0&#93;.v = miny;
	vertices&#91;0&#93;.color = 0;
	vertices&#91;0&#93;.x = playerX;
	vertices&#91;0&#93;.y = playerY;
	vertices&#91;0&#93;.z = 0;

	vertices&#91;1&#93;.u = minx; 
	vertices&#91;1&#93;.v = miny+maxy;
	vertices&#91;1&#93;.color = 0;
	vertices&#91;1&#93;.x = playerX;
	vertices&#91;1&#93;.y = playerY+maxy;
	vertices&#91;1&#93;.z = 0;

	vertices&#91;2&#93;.u = minx+maxx; 
	vertices&#91;2&#93;.v = miny;
	vertices&#91;2&#93;.color = 0;
	vertices&#91;2&#93;.x = playerX+maxx;
	vertices&#91;2&#93;.y = playerY;
	vertices&#91;2&#93;.z = 0;


	vertices&#91;3&#93;.u = minx+maxx; 
	vertices&#91;3&#93;.v = miny+maxy;
	vertices&#91;3&#93;.color = 0;
	vertices&#91;3&#93;.x = playerX+maxx;
	vertices&#91;3&#93;.y = playerY+maxy;
	vertices&#91;3&#93;.z = 0;
	sceGumLoadIdentity&#40;&#41;; 
	sceGumRotateX&#40;50.0f&#41;;
	sceGuDrawArray&#40;GU_TRIANGLE_STRIP,GU_TEXTURE_16BIT|GU_COLOR_8888|GU_VERTEX_16BIT|GU_TRANSFORM_2D,4,0,vertices&#41;;

However I can see only half of my image and it is not rotated whatsoever. I am missing anything here?

Noware · Post by **Noware** » Fri Mar 27, 2009 4:20 am

update the angle

sceGumLoadIdentity();
static float angle = 0.0f;
angle+= 1.0f;
sceGumRotateX(angle);

Noware

sigutis · Post by **sigutis** » Fri Mar 27, 2009 6:30 am

I figured I have to set GU_TRANSFORM_2D to GU_TRANSFORM_3D but now I can't see anything. The further the better....

Smong · Post by **Smong** » Fri Mar 27, 2009 7:38 am

You don't want to use GU_TEXTURE_16BIT and GU_VERTEX_16BIT in GU_TRANSFORM_3D mode unless you prescale your vertices. It would be a lot easier to use the 32BITF versions.

sigutis · Post by **sigutis** » Fri Mar 27, 2009 4:21 pm

I see. Well, there's one thing bothering me about the 32BITF vertices. I am currently using a vertex struct size of 16 bytes in the 16BIT mode. If I was to use 32BITF logically I need a vertex structure of 32 byte size. And I have no idea what could I put in there to double the size.

Code: Select all

struct Vertex
&#123;
	unsigned int u, v;   //texture coordinates
	unsigned int color; //color which I don't use
	int x, y, z;            //coords
	long a,b;              //useless variables to fit into the 32 byte range

&#125;;

I have no idea how else could I make a 32 byte vertex, do you?

Smong · Post by **Smong** » Sat Mar 28, 2009 7:42 am

Have a look at samples/gu/common/geometry.h
For 32BITF you want something like:

Code: Select all

struct Vertex
&#123;
    float u, v;
    float x, y, z;
&#125;;

You said you don't use the color so just take GU_COLOR_8888 out of the sceGuDrawArray call.

32BITF means 32 bit float, so that's just a float, not a double. It doesn't mean the vertex struct is 32 bytes, but it may coincidentally be that size.

sigutis · Post by **sigutis** » Sun Mar 29, 2009 3:34 am

Thanks for the help I really appreciate it. I have done some tweaking using the information you guys provided, but it seems that hardware rotation is just not for me. I switched to manually rotating those vertexes with some trigonometry. Take care.

Smong · Post by **Smong** » Sun Mar 29, 2009 5:10 am

You could have a look at the ortho sample included in pspsdk. It draws a triangle and rotates it.