draw3d.c

#include <gif_tags.h>
 
#include <gs_gp.h>
#include <gs_privileged.h>
 
#include <draw.h>
 
// Starting position of primitive
static qword_t *__prim_start = NULL;
 
qword_t *draw_prim_start(qword_t *q, int context, const prim_t *prim, const color_t *color)
{
 
    // Set the primitive register in packed mode, but don't end the packet
    PACK_GIFTAG(q,GIF_SET_TAG(2,0,0,0,GIF_FLG_PACKED,1),GIF_REG_AD);
    q++;
    PACK_GIFTAG(q,GS_SET_PRIM(prim->type,prim->shading,prim->mapping,prim->fogging,
                              prim->blending,prim->antialiasing,prim->mapping_type,
                              context,prim->colorfix),GS_REG_PRIM);
    q++;
    PACK_GIFTAG(q,color->rgbaq,GIF_REG_RGBAQ);
    q++;
 
    // Save the position for the reglist giftag that draw_primitive_end will add
    __prim_start = q;
    q++;
 
    // Return the current qword pointer
    return q;
 
}
 
qword_t *draw_prim_end(qword_t *q, int nreg, u64 reglist)
{
 
    u32 vertex_qwords;
    u32 vertex_loops;
 
    // Determine number qwords that were needed minus the reglist giftag
    vertex_qwords = q - __prim_start - 1;
 
    // Determine number of loops based on qwords used and number of regs per loop
    vertex_loops = (vertex_qwords * 2) / nreg;
 
    // Now set the giftag of the vertex reglist chain
    __prim_start->dw[0] = GIF_SET_TAG(vertex_loops,1,0,0,GIF_FLG_REGLIST,nreg);
 
    // Set the higher 64bits to the reglist
    __prim_start->dw[1] = reglist;
 
    // Return the current qword pointer
    return q;
 
}
 
int draw_convert_rgbq(color_t *output, int count, vertex_f_t *vertices, color_f_t *colours, unsigned char alpha)
{
 
    int i;
    float q = 1.00f;
 
    // For each colour...
    for (i=0;i<count;i++)
    {
 
        // Calculate the Q value.
        if (vertices[i].w != 0)
        {
 
            q = 1 / vertices[i].w;
 
        }
 
        // Calculate the RGBA values.
        output[i].r = (int)(colours[i].r * 128.0f);
        output[i].g = (int)(colours[i].g * 128.0f);
        output[i].b = (int)(colours[i].b * 128.0f);
        output[i].a = alpha;
        output[i].q = q;
 
    }
 
    // End function.
    return 0;
 
}
 
int draw_convert_rgbaq(color_t *output, int count, vertex_f_t *vertices, color_f_t *colours)
{
 
    int i;
    float q = 1.00f;
 
    // For each colour...
    for (i=0;i<count;i++)
    {
 
        // Calculate the Q value.
        if (vertices[i].w != 0)
        {
 
            q = 1 / vertices[i].w;
 
        }
 
        // Calculate the RGBA values.
        output[i].r = (int)(colours[i].r * 128.0f);
        output[i].g = (int)(colours[i].g * 128.0f);
        output[i].b = (int)(colours[i].b * 128.0f);
        output[i].a = (int)(colours[i].a * 128.0f);
        output[i].q = q;
 
    }
 
    // End function.
    return 0;
 
}
 
int draw_convert_st(texel_t *output, int count, vertex_f_t *vertices, texel_f_t *coords)
{
 
    int i = 0;
    float q = 1.00f;
 
    // For each coordinate...
    for (i=0;i<count;i++)
    {
 
        // Calculate the Q value.
        if (vertices[i].w != 0)
        {
            q = 1 / vertices[i].w;
        }
 
        // Calculate the S and T values.
        output[i].s = coords[i].s * q;
        output[i].t = coords[i].t * q;
 
    }
 
    // End function.
    return 0;
 
}
 
int draw_convert_xyz(xyz_t *output, float x, float y, int z, int count, vertex_f_t *vertices)
{
 
    int i;
 
    int center_x;
    int center_y;
 
    unsigned int max_z;
 
    center_x = ftoi4(x);
    center_y = ftoi4(y);
 
    max_z = 1 << (z - 1);
 
    // For each colour...
    for (i=0;i<count;i++)
    {
 
        // Calculate the XYZ values.
        output[i].x = (short)((vertices[i].x + 1.0f) * center_x);
        output[i].y = (short)((vertices[i].y + 1.0f) * -center_y);
        output[i].z = (unsigned int)((vertices[i].z + 1.0f) * max_z);
 
    }
 
    // End function.
    return 0;
 
}