746 lines
28 KiB
C
Executable File
746 lines
28 KiB
C
Executable File
/* KallistiGL for KallistiOS ##version##
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libgl/gl-clip.c
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Copyright (C) 2013-2014 Josh "PH3NOM" Pearson
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Near-Z Clipping Algorithm (C) 2013-2014 Josh PH3NOM Pearson
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Input Primitive Types Supported:
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-GL_TRIANGLES
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-GL_TRIANGLE_STRIPS
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-GL_QUADS
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Outputs a mix of Triangles and Triangle Strips for use with the PVR
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*/
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#include <stdio.h>
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#include <string.h>
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#include "gl-clip.h"
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static float3 CLIP_BUF[1024 * 32];
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static inline void glVertexCopy3f(float3 *src, float3 *dst) {
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*dst = *src;
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}
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static inline void glVertexCopyPVR(pvr_vertex_t *src, pvr_vertex_t *dst) {
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*dst = *src;
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}
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static inline void _glKosVertexCopyPVR(pvr_vertex_t *src, pvr_vertex_t *dst) {
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*dst = *src;
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}
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static inline float ZclipMag(float3 *v1, float3 *v2) {
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return ((CLIP_NEARZ - v1->z) / (v2->z - v1->z));
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}
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static inline void glVertexClipZNear(pvr_vertex_t *v1, pvr_vertex_t *v2, float MAG) {
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colorui *c1 = (colorui *)&v1->argb;
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colorui *c2 = (colorui *)&v2->argb;
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v1->x += (v2->x - v1->x) * MAG;
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v1->y += (v2->y - v1->y) * MAG;
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v1->z += (v2->z - v1->z) * MAG;
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v1->u += (v2->u - v1->u) * MAG;
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v1->v += (v2->v - v1->v) * MAG;
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c1->a += (c2->a - c1->a) * MAG;
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c1->r += (c2->r - c1->r) * MAG;
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c1->g += (c2->g - c1->g) * MAG;
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c1->b += (c2->b - c1->b) * MAG;
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}
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static inline void _glKosVertexClipZNear3(pvr_vertex_t *v1, pvr_vertex_t *v2, float *w1, float *w2) {
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float MAG = ((CLIP_NEARZ - v1->z) / (v2->z - v1->z));
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colorui *c1 = (colorui *)&v1->argb;
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colorui *c2 = (colorui *)&v2->argb;
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v1->x += (v2->x - v1->x) * MAG;
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v1->y += (v2->y - v1->y) * MAG;
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v1->z += (v2->z - v1->z) * MAG;
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v1->u += (v2->u - v1->u) * MAG;
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v1->v += (v2->v - v1->v) * MAG;
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c1->a += (c2->a - c1->a) * MAG;
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c1->r += (c2->r - c1->r) * MAG;
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c1->g += (c2->g - c1->g) * MAG;
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c1->b += (c2->b - c1->b) * MAG;
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*w1 += (*w2 - *w1) * MAG;
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}
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static GLuint glTransformClip(pvr_vertex_t *v, int count) {
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pvr_vertex_t *V = v;
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float3 *C = CLIP_BUF;
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GLuint in = 0;
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while(count--) {
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mat_trans_single3_nodiv_nomod(V->x, V->y, V->z, C->x, C->y, C->z);
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if(C->z < CLIP_NEARZ) ++in;
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++C;
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++V;
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}
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return in;
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}
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GLuint _glKosClipTriangleStrip(pvr_vertex_t *vin, pvr_vertex_t *vout, unsigned int vertices) {
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GLuint i, v = 0, in = glTransformClip(vin, vertices);
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float3 *C = CLIP_BUF;
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if(in == vertices) {
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memcpy(vout, vin, vertices * 0x20);
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pvr_vertex_t *v = vout;
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while(--in) {
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v->flags = PVR_CMD_VERTEX;
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++v;
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}
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v->flags = PVR_CMD_VERTEX_EOL;
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return vertices;
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}
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else if(in == 0)
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return 0;
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/* Iterate all Triangles of the Strip - Hence looping vertices-2 times */
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for(i = 0; i < ((vertices) - 2); i++) {
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unsigned short int clip = 0; /* Clip Code for current Triangle */
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unsigned char verts_in = 0; /* # of Verteices inside clip plane for current Triangle */
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C->z >= CLIP_NEARZ ? clip |= FIRST : ++verts_in;
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(C + 1)->z >= CLIP_NEARZ ? clip |= SECOND : ++verts_in;
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(C + 2)->z >= CLIP_NEARZ ? clip |= THIRD : ++verts_in;
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switch(verts_in) { /* Start by examining # of vertices inside clip plane */
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case 0: /* All Vertices of Triangle are outside of clip plne */
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break;
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case 3: /* All Vertices of Triangle are inside of clip plne */
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memcpy(&vout[v], &vin[i], 96);
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vout[v].flags = vout[v + 1].flags = PVR_CMD_VERTEX;
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vout[v + 2].flags = PVR_CMD_VERTEX_EOL;
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v += 3;
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break;
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case 1:/* 1 Vertex of Triangle is inside of clip plane = output 1 Triangle */
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memcpy(&vout[v], &vin[i], 96);
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switch(clip) {
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case FIRST_TWO_OUT:
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glVertexClipZNear(&vout[v], &vout[v + 2], ZclipMag(&CLIP_BUF[i], &CLIP_BUF[i + 2]));
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glVertexClipZNear(&vout[v + 1], &vout[v + 2], ZclipMag(&CLIP_BUF[i + 1], &CLIP_BUF[i + 2]));
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break;
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case FIRST_AND_LAST_OUT:
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glVertexClipZNear(&vout[v], &vout[v + 1], ZclipMag(&CLIP_BUF[i], &CLIP_BUF[i + 1]));
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glVertexClipZNear(&vout[v + 2], &vout[v + 1], ZclipMag(&CLIP_BUF[i + 2], &CLIP_BUF[i + 1]));
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break;
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case LAST_TWO_OUT:
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glVertexClipZNear(&vout[v + 1], &vout[v], ZclipMag(&CLIP_BUF[i + 1], &CLIP_BUF[i + 0]));
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glVertexClipZNear(&vout[v + 2], &vout[v], ZclipMag(&CLIP_BUF[i + 2], &CLIP_BUF[i + 0]));
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break;
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}
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vout[v].flags = vout[v + 1].flags = PVR_CMD_VERTEX;
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vout[v + 2].flags = PVR_CMD_VERTEX_EOL;
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v += 3;
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break;
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case 2:/* 2 Vertices of Triangle are inside of clip plane = output 2 Triangles */
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switch(clip) {
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case FIRST:
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glVertexCopyPVR(&vin[i + 0], &vout[v + 0]);
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glVertexCopyPVR(&vin[i + 1], &vout[v + 1]);
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glVertexCopyPVR(&vin[i + 0], &vout[v + 2]);
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glVertexCopyPVR(&vin[i + 2], &vout[v + 3]);
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glVertexClipZNear(&vout[v + 0], &vout[v + 1], ZclipMag(&CLIP_BUF[i], &CLIP_BUF[i + 1]));
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glVertexClipZNear(&vout[v + 2], &vout[v + 3], ZclipMag(&CLIP_BUF[i], &CLIP_BUF[i + 2]));
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break;
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case SECOND:
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glVertexCopyPVR(&vin[i + 1], &vout[v + 0]);
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glVertexCopyPVR(&vin[i + 0], &vout[v + 1]);
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glVertexCopyPVR(&vin[i + 1], &vout[v + 2]);
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glVertexCopyPVR(&vin[i + 2], &vout[v + 3]);
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glVertexClipZNear(&vout[v + 0], &vout[v + 1], ZclipMag(&CLIP_BUF[i + 1], &CLIP_BUF[i + 0]));
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glVertexClipZNear(&vout[v + 2], &vout[v + 3], ZclipMag(&CLIP_BUF[i + 1], &CLIP_BUF[i + 2]));
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break;
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case THIRD:
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glVertexCopyPVR(&vin[i + 2], &vout[v + 0]);
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glVertexCopyPVR(&vin[i + 0], &vout[v + 1]);
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glVertexCopyPVR(&vin[i + 2], &vout[v + 2]);
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glVertexCopyPVR(&vin[i + 1], &vout[v + 3]);
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glVertexClipZNear(&vout[v + 0], &vout[v + 1], ZclipMag(&CLIP_BUF[i + 2], &CLIP_BUF[i]));
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glVertexClipZNear(&vout[v + 2], &vout[v + 3], ZclipMag(&CLIP_BUF[i + 2], &CLIP_BUF[i + 1]));
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break;
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}
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vout[v + 0].flags = vout[v + 1].flags = vout[v + 2].flags = PVR_CMD_VERTEX;
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vout[v + 3].flags = PVR_CMD_VERTEX_EOL;
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v += 4;
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break;
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}
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C++;
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}
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return v;
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}
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static inline unsigned char _glKosClipTri(pvr_vertex_t *vin, pvr_vertex_t *vout) {
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unsigned short int clip = 0; /* Clip Code for current Triangle */
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unsigned char verts_in = 0; /* # of Vertices inside clip plane for current Triangle */
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float3 clip_buf[3]; /* Store the Vertices for each Triangle Translated into Clip Space */
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/* Transform all 3 Vertices of Triangle */
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{
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register float __x __asm__("fr12") = vin->x;
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register float __y __asm__("fr13") = vin->y;
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register float __z __asm__("fr14") = vin->z;
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mat_trans_fv12_nodiv();
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clip_buf[0].x = __x;
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clip_buf[0].y = __y;
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clip_buf[0].z = __z;
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__x = (vin + 1)->x;
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__y = (vin + 1)->y;
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__z = (vin + 1)->z;
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mat_trans_fv12_nodiv();
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clip_buf[1].x = __x;
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clip_buf[1].y = __y;
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clip_buf[1].z = __z;
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__x = (vin + 2)->x;
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__y = (vin + 2)->y;
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__z = (vin + 2)->z;
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mat_trans_fv12_nodiv();
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clip_buf[2].x = __x;
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clip_buf[2].y = __y;
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clip_buf[2].z = __z;
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/* Compute Clip Code for Triangle */
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(clip_buf[0].z >= CLIP_NEARZ) ? clip |= FIRST : ++verts_in;
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(clip_buf[1].z >= CLIP_NEARZ) ? clip |= SECOND : ++verts_in;
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(clip_buf[2].z >= CLIP_NEARZ) ? clip |= THIRD : ++verts_in;
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}
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switch(verts_in) { /* Start by examining # of vertices inside clip plane */
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case 0: /* All Vertices of Triangle are Outside of clip plne */
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return 0;
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case 3: /* All Vertices of Triangle are inside of clip plne */
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memcpy(vout, vin, 96);
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vout->flags = (vout + 1)->flags = PVR_CMD_VERTEX;
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(vout + 2)->flags = PVR_CMD_VERTEX_EOL;
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return 3;
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case 1:/* 1 Vertex of Triangle is inside of clip plane = output 1 Triangle */
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memcpy(vout, vin, 96);
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switch(clip) {
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case FIRST_TWO_OUT:
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glVertexClipZNear(vout, vout + 2, ZclipMag(&clip_buf[0], &clip_buf[2]));
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glVertexClipZNear(vout + 1, vout + 2, ZclipMag(&clip_buf[1], &clip_buf[2]));
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break;
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case FIRST_AND_LAST_OUT:
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glVertexClipZNear(vout, vout + 1, ZclipMag(&clip_buf[0], &clip_buf[1]));
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glVertexClipZNear(vout + 2, vout + 1, ZclipMag(&clip_buf[2], &clip_buf[1]));
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break;
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case LAST_TWO_OUT:
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glVertexClipZNear(vout + 1, vout, ZclipMag(&clip_buf[1], &clip_buf[0]));
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glVertexClipZNear(vout + 2, vout, ZclipMag(&clip_buf[2], &clip_buf[0]));
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break;
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}
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vout->flags = (vout + 1)->flags = PVR_CMD_VERTEX;
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(vout + 2)->flags = PVR_CMD_VERTEX_EOL;
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return 3;
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case 2:/* 2 Vertices of Triangle are inside of clip plane = output 2 Triangles */
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switch(clip) {
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case FIRST:
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memcpy(vout, vin, 64);
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glVertexCopyPVR(vin, vout + 2);
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glVertexCopyPVR(vin + 2, vout + 3);
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glVertexClipZNear(vout, vout + 1, ZclipMag(&clip_buf[0], &clip_buf[1]));
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glVertexClipZNear(vout + 2, vout + 3, ZclipMag(&clip_buf[0], &clip_buf[2]));
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break;
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case SECOND:
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glVertexCopyPVR(vin + 1, vout);
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glVertexCopyPVR(vin, vout + 1);
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memcpy(vout + 2, vin + 1, 64);
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glVertexClipZNear(vout, vout + 1, ZclipMag(&clip_buf[1], &clip_buf[0]));
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glVertexClipZNear(vout + 2, vout + 3, ZclipMag(&clip_buf[1], &clip_buf[2]));
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break;
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case THIRD:
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glVertexCopyPVR(vin + 2, vout);
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glVertexCopyPVR(vin, vout + 1);
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glVertexCopyPVR(vin + 2, vout + 2);
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glVertexCopyPVR(vin + 1, vout + 3);
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glVertexClipZNear(vout, vout + 1, ZclipMag(&clip_buf[2], &clip_buf[0]));
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glVertexClipZNear(vout + 2, vout + 3, ZclipMag(&clip_buf[2], &clip_buf[1]));
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break;
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}
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vout->flags = (vout + 1)->flags = (vout + 2)->flags = PVR_CMD_VERTEX;
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(vout + 3)->flags = PVR_CMD_VERTEX_EOL;
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return 4;
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}
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return 0;
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}
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unsigned int _glKosClipTriangles(pvr_vertex_t *vin, pvr_vertex_t *vout, unsigned int vertices) {
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unsigned int i, v = 0;
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for(i = 0; i < vertices; i += 3) /* Iterate all Triangles */
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v += _glKosClipTri(vin + i, vout + v);
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return v;
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}
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unsigned int _glKosClipQuads(pvr_vertex_t *vin, pvr_vertex_t *vout, unsigned int vertices) {
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unsigned int i, v = 0;
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pvr_vertex_t qv;
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for(i = 0; i < vertices; i += 4) { /* Iterate all Quads, Rearranging into Triangle Strips */
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glVertexCopyPVR(vin + i + 3, &qv);
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glVertexCopyPVR(vin + i + 2, vin + i + 3);
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glVertexCopyPVR(&qv, vin + i + 2);
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v += _glKosClipTriangleStrip(vin + i, vout + v, 4);
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}
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return v;
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}
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static inline void _glKosVertexPerspectiveDivide(pvr_vertex_t *dst, float w) {
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dst->z = 1.0f / w;
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dst->x *= dst->z;
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dst->y *= dst->z;
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}
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GLuint _glKosClipTrianglesTransformed(pvr_vertex_t *src, float *w, pvr_vertex_t *dst, GLuint count) {
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pvr_vertex_t *vin = src;
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pvr_vertex_t *vout = dst;
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unsigned short int clip;
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unsigned char verts_in = 0;
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GLuint verts_out = 0;
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GLuint i;
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for(i = 0; i < count; i += 3) {
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clip = 0; /* Clip Code for current Triangle */
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verts_in = 0; /* # of Vertices inside clip plane for current Triangle */
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float W[4] = { w[i], w[i + 1], w[i + 2] }; /* W Component for Perspective Divide */
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(vin[0].z >= CLIP_NEARZ) ? clip |= FIRST : ++verts_in;
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(vin[1].z >= CLIP_NEARZ) ? clip |= SECOND : ++verts_in;
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(vin[2].z >= CLIP_NEARZ) ? clip |= THIRD : ++verts_in;
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switch(verts_in) { /* Start by examining # of vertices inside clip plane */
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case 0: /* All Vertices of Triangle are Outside of clip plne */
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break;
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case 3: /* All Vertices of Triangle are inside of clip plne */
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_glKosVertexCopyPVR(&vin[0], &vout[0]);
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_glKosVertexCopyPVR(&vin[1], &vout[1]);
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_glKosVertexCopyPVR(&vin[2], &vout[2]);
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_glKosVertexPerspectiveDivide(&vout[0], W[0]);
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_glKosVertexPerspectiveDivide(&vout[1], W[1]);
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_glKosVertexPerspectiveDivide(&vout[2], W[2]);
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vout[0].flags = vout[1].flags = PVR_CMD_VERTEX;
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vout[2].flags = PVR_CMD_VERTEX_EOL;
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vout += 3;
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verts_out += 3;
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break;
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case 1:/* 1 Vertex of Triangle is inside of clip plane = output 1 Triangle */
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_glKosVertexCopyPVR(&vin[0], &vout[0]);
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_glKosVertexCopyPVR(&vin[1], &vout[1]);
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_glKosVertexCopyPVR(&vin[2], &vout[2]);
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switch(clip) {
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case FIRST_TWO_OUT:
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_glKosVertexClipZNear3(&vout[0], &vout[2], &W[0], &W[2]);
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_glKosVertexClipZNear3(&vout[1], &vout[2], &W[1], &W[2]);
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break;
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case FIRST_AND_LAST_OUT:
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_glKosVertexClipZNear3(&vout[0], &vout[1], &W[0], &W[1]);
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_glKosVertexClipZNear3(&vout[2], &vout[1], &W[2], &W[1]);
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break;
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case LAST_TWO_OUT:
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_glKosVertexClipZNear3(&vout[1], &vout[0], &W[1], &W[0]);
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_glKosVertexClipZNear3(&vout[2], &vout[0], &W[2], &W[0]);
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break;
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}
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_glKosVertexPerspectiveDivide(&vout[0], W[0]);
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_glKosVertexPerspectiveDivide(&vout[1], W[1]);
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_glKosVertexPerspectiveDivide(&vout[2], W[2]);
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vout[0].flags = vout[1].flags = PVR_CMD_VERTEX;
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vout[2].flags = PVR_CMD_VERTEX_EOL;
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vout += 3;
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verts_out += 3;
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break;
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case 2:/* 2 Vertices of Triangle are inside of clip plane = output 2 Triangles */
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switch(clip) {
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case FIRST:
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_glKosVertexCopyPVR(&vin[0], &vout[0]);
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_glKosVertexCopyPVR(&vin[1], &vout[1]);
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_glKosVertexCopyPVR(&vin[0], &vout[2]);
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_glKosVertexCopyPVR(&vin[2], &vout[3]);
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W[3] = W[2];
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W[2] = W[0];
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break;
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|
|
case SECOND:
|
|
_glKosVertexCopyPVR(&vin[1], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[2]);
|
|
_glKosVertexCopyPVR(&vin[0], &vout[3]);
|
|
W[3] = W[0];
|
|
W[0] = W[1];
|
|
W[1] = W[2];
|
|
W[2] = W[0];
|
|
|
|
break;
|
|
|
|
case THIRD:
|
|
_glKosVertexCopyPVR(&vin[2], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[0], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[2]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[3]);
|
|
W[3] = W[1];
|
|
W[1] = W[0];
|
|
W[0] = W[2];
|
|
|
|
break;
|
|
}
|
|
|
|
_glKosVertexClipZNear3(&vout[0], &vout[1], &W[0], &W[1]);
|
|
_glKosVertexClipZNear3(&vout[2], &vout[3], &W[2], &W[3]);
|
|
|
|
_glKosVertexPerspectiveDivide(&vout[0], W[0]);
|
|
_glKosVertexPerspectiveDivide(&vout[1], W[1]);
|
|
_glKosVertexPerspectiveDivide(&vout[2], W[2]);
|
|
_glKosVertexPerspectiveDivide(&vout[3], W[3]);
|
|
|
|
vout[0].flags = vout[1].flags = vout[2].flags = PVR_CMD_VERTEX;
|
|
vout[3].flags = PVR_CMD_VERTEX_EOL;
|
|
|
|
vout += 4;
|
|
verts_out += 4;
|
|
break;
|
|
}
|
|
|
|
vin += 3;
|
|
}
|
|
|
|
return verts_out;
|
|
}
|
|
|
|
GLuint _glKosClipTriangleStripTransformed(pvr_vertex_t *src, float *w, pvr_vertex_t *dst, GLuint count) {
|
|
pvr_vertex_t *vin = src;
|
|
pvr_vertex_t *vout = dst;
|
|
unsigned short int clip;
|
|
unsigned char verts_in = 0;
|
|
GLuint verts_out = 0;
|
|
GLuint i;
|
|
|
|
for(i = 0; i < (count - 2); i ++) {
|
|
clip = 0; /* Clip Code for current Triangle */
|
|
verts_in = 0; /* # of Vertices inside clip plane for current Triangle */
|
|
float W[4] = { w[i], w[i + 1], w[i + 2] }; /* W Component for Perspective Divide */
|
|
|
|
(vin[0].z >= CLIP_NEARZ) ? clip |= FIRST : ++verts_in;
|
|
(vin[1].z >= CLIP_NEARZ) ? clip |= SECOND : ++verts_in;
|
|
(vin[2].z >= CLIP_NEARZ) ? clip |= THIRD : ++verts_in;
|
|
|
|
switch(verts_in) { /* Start by examining # of vertices inside clip plane */
|
|
case 0: /* All Vertices of Triangle are Outside of clip plne */
|
|
break;
|
|
|
|
case 3: /* All Vertices of Triangle are inside of clip plne */
|
|
_glKosVertexCopyPVR(&vin[0], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[2]);
|
|
|
|
_glKosVertexPerspectiveDivide(&vout[0], W[0]);
|
|
_glKosVertexPerspectiveDivide(&vout[1], W[1]);
|
|
_glKosVertexPerspectiveDivide(&vout[2], W[2]);
|
|
|
|
vout[0].flags = vout[1].flags = PVR_CMD_VERTEX;
|
|
vout[2].flags = PVR_CMD_VERTEX_EOL;
|
|
|
|
vout += 3;
|
|
verts_out += 3;
|
|
break;
|
|
|
|
case 1:/* 1 Vertex of Triangle is inside of clip plane = output 1 Triangle */
|
|
_glKosVertexCopyPVR(&vin[0], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[2]);
|
|
|
|
switch(clip) {
|
|
case FIRST_TWO_OUT:
|
|
_glKosVertexClipZNear3(&vout[0], &vout[2], &W[0], &W[2]);
|
|
_glKosVertexClipZNear3(&vout[1], &vout[2], &W[1], &W[2]);
|
|
|
|
break;
|
|
|
|
case FIRST_AND_LAST_OUT:
|
|
_glKosVertexClipZNear3(&vout[0], &vout[1], &W[0], &W[1]);
|
|
_glKosVertexClipZNear3(&vout[2], &vout[1], &W[2], &W[1]);
|
|
|
|
break;
|
|
|
|
case LAST_TWO_OUT:
|
|
_glKosVertexClipZNear3(&vout[1], &vout[0], &W[1], &W[0]);
|
|
_glKosVertexClipZNear3(&vout[2], &vout[0], &W[2], &W[0]);
|
|
|
|
break;
|
|
}
|
|
|
|
_glKosVertexPerspectiveDivide(&vout[0], W[0]);
|
|
_glKosVertexPerspectiveDivide(&vout[1], W[1]);
|
|
_glKosVertexPerspectiveDivide(&vout[2], W[2]);
|
|
|
|
vout[0].flags = vout[1].flags = PVR_CMD_VERTEX;
|
|
vout[2].flags = PVR_CMD_VERTEX_EOL;
|
|
|
|
vout += 3;
|
|
verts_out += 3;
|
|
break;
|
|
|
|
case 2:/* 2 Vertices of Triangle are inside of clip plane = output 2 Triangles */
|
|
switch(clip) {
|
|
case FIRST:
|
|
_glKosVertexCopyPVR(&vin[0], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[0], &vout[2]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[3]);
|
|
W[3] = W[2];
|
|
W[2] = W[0];
|
|
|
|
break;
|
|
|
|
case SECOND:
|
|
_glKosVertexCopyPVR(&vin[1], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[2]);
|
|
_glKosVertexCopyPVR(&vin[0], &vout[3]);
|
|
W[3] = W[0];
|
|
W[0] = W[1];
|
|
W[1] = W[2];
|
|
W[2] = W[0];
|
|
|
|
break;
|
|
|
|
case THIRD:
|
|
_glKosVertexCopyPVR(&vin[2], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[0], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[2]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[3]);
|
|
W[3] = W[1];
|
|
W[1] = W[0];
|
|
W[0] = W[2];
|
|
|
|
break;
|
|
}
|
|
|
|
_glKosVertexClipZNear3(&vout[0], &vout[1], &W[0], &W[1]);
|
|
_glKosVertexClipZNear3(&vout[2], &vout[3], &W[2], &W[3]);
|
|
|
|
_glKosVertexPerspectiveDivide(&vout[0], W[0]);
|
|
_glKosVertexPerspectiveDivide(&vout[1], W[1]);
|
|
_glKosVertexPerspectiveDivide(&vout[2], W[2]);
|
|
_glKosVertexPerspectiveDivide(&vout[3], W[3]);
|
|
|
|
vout[0].flags = vout[1].flags = vout[2].flags = PVR_CMD_VERTEX;
|
|
vout[3].flags = PVR_CMD_VERTEX_EOL;
|
|
|
|
vout += 4;
|
|
verts_out += 4;
|
|
break;
|
|
}
|
|
|
|
++vin;
|
|
}
|
|
|
|
return verts_out;
|
|
}
|
|
|
|
GLubyte _glKosClipTriTransformed(pvr_vertex_t *vin, float *w, pvr_vertex_t *vout) {
|
|
unsigned short int clip = 0; /* Clip Code for current Triangle */
|
|
unsigned char verts_in = 0; /* # of Vertices inside clip plane for current Triangle */
|
|
float W[4] = { w[0], w[1], w[2] }; /* W Component for Perspective Divide */
|
|
|
|
(vin[0].z >= CLIP_NEARZ) ? clip |= FIRST : ++verts_in;
|
|
(vin[1].z >= CLIP_NEARZ) ? clip |= SECOND : ++verts_in;
|
|
(vin[2].z >= CLIP_NEARZ) ? clip |= THIRD : ++verts_in;
|
|
|
|
switch(verts_in) { /* Start by examining # of vertices inside clip plane */
|
|
case 0: /* All Vertices of Triangle are Outside of clip plne */
|
|
return 0;
|
|
|
|
case 3: /* All Vertices of Triangle are inside of clip plne */
|
|
_glKosVertexCopyPVR(&vin[0], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[2]);
|
|
|
|
_glKosVertexPerspectiveDivide(&vout[0], W[0]);
|
|
_glKosVertexPerspectiveDivide(&vout[1], W[1]);
|
|
_glKosVertexPerspectiveDivide(&vout[2], W[2]);
|
|
|
|
vout[0].flags = vout[1].flags = PVR_CMD_VERTEX;
|
|
vout[2].flags = PVR_CMD_VERTEX_EOL;
|
|
|
|
return 3;
|
|
|
|
case 1:/* 1 Vertex of Triangle is inside of clip plane = output 1 Triangle */
|
|
_glKosVertexCopyPVR(&vin[0], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[2]);
|
|
|
|
switch(clip) {
|
|
case FIRST_TWO_OUT:
|
|
_glKosVertexClipZNear3(&vout[0], &vout[2], &W[0], &W[2]);
|
|
_glKosVertexClipZNear3(&vout[1], &vout[2], &W[1], &W[2]);
|
|
|
|
break;
|
|
|
|
case FIRST_AND_LAST_OUT:
|
|
_glKosVertexClipZNear3(&vout[0], &vout[1], &W[0], &W[1]);
|
|
_glKosVertexClipZNear3(&vout[2], &vout[1], &W[2], &W[1]);
|
|
|
|
break;
|
|
|
|
case LAST_TWO_OUT:
|
|
_glKosVertexClipZNear3(&vout[1], &vout[0], &W[1], &W[0]);
|
|
_glKosVertexClipZNear3(&vout[2], &vout[0], &W[2], &W[0]);
|
|
|
|
break;
|
|
}
|
|
|
|
_glKosVertexPerspectiveDivide(&vout[0], W[0]);
|
|
_glKosVertexPerspectiveDivide(&vout[1], W[1]);
|
|
_glKosVertexPerspectiveDivide(&vout[2], W[2]);
|
|
|
|
vout[0].flags = vout[1].flags = PVR_CMD_VERTEX;
|
|
vout[2].flags = PVR_CMD_VERTEX_EOL;
|
|
|
|
return 3;
|
|
|
|
case 2:/* 2 Vertices of Triangle are inside of clip plane = output 2 Triangles */
|
|
switch(clip) {
|
|
case FIRST:
|
|
_glKosVertexCopyPVR(&vin[0], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[0], &vout[2]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[3]);
|
|
W[3] = W[2];
|
|
W[2] = W[0];
|
|
|
|
break;
|
|
|
|
case SECOND:
|
|
_glKosVertexCopyPVR(&vin[1], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[2]);
|
|
_glKosVertexCopyPVR(&vin[0], &vout[3]);
|
|
W[3] = W[0];
|
|
W[0] = W[1];
|
|
W[1] = W[2];
|
|
W[2] = W[0];
|
|
|
|
break;
|
|
|
|
case THIRD:
|
|
_glKosVertexCopyPVR(&vin[2], &vout[0]);
|
|
_glKosVertexCopyPVR(&vin[0], &vout[1]);
|
|
_glKosVertexCopyPVR(&vin[2], &vout[2]);
|
|
_glKosVertexCopyPVR(&vin[1], &vout[3]);
|
|
W[3] = W[1];
|
|
W[1] = W[0];
|
|
W[0] = W[2];
|
|
|
|
break;
|
|
}
|
|
|
|
_glKosVertexClipZNear3(&vout[0], &vout[1], &W[0], &W[1]);
|
|
_glKosVertexClipZNear3(&vout[2], &vout[3], &W[2], &W[3]);
|
|
|
|
_glKosVertexPerspectiveDivide(&vout[0], W[0]);
|
|
_glKosVertexPerspectiveDivide(&vout[1], W[1]);
|
|
_glKosVertexPerspectiveDivide(&vout[2], W[2]);
|
|
_glKosVertexPerspectiveDivide(&vout[3], W[3]);
|
|
|
|
vout[0].flags = vout[1].flags = vout[2].flags = PVR_CMD_VERTEX;
|
|
vout[3].flags = PVR_CMD_VERTEX_EOL;
|
|
|
|
return 4;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
unsigned int _glKosClipQuadsTransformed(pvr_vertex_t *vin, float *w, pvr_vertex_t *vout, unsigned int vertices) {
|
|
unsigned int i, v = 0;
|
|
pvr_vertex_t qv[3];
|
|
float W[3];
|
|
|
|
for(i = 0; i < vertices; i += 4) { /* Iterate all Quads, Rearranging into Triangle Strips */
|
|
_glKosVertexCopyPVR(&vin[i + 0], &qv[0]);
|
|
_glKosVertexCopyPVR(&vin[i + 2], &qv[1]);
|
|
_glKosVertexCopyPVR(&vin[i + 3], &qv[2]);
|
|
W[0] = w[0];
|
|
W[1] = w[2];
|
|
W[2] = w[3];
|
|
|
|
v += _glKosClipTriTransformed(&vin[i], &w[i], &vout[v]);
|
|
v += _glKosClipTriTransformed(&qv[i], &W[i], &vout[v]);
|
|
}
|
|
|
|
return v;
|
|
}
|