diff --git a/world.c b/world.c index 1f26f3b..397b2cd 100644 --- a/world.c +++ b/world.c @@ -38,6 +38,178 @@ void world_load(const u_long *data, world_t *world) bytes += sizeof(ps1bsp_face_t) * world->header->numFaces; } +static inline void drawface_triangle_fan(const ps1bsp_face_t *face, SVECTOR *vecs) +{ + int p; + + // Draw the face as a triangle fan + u_char maxVert = face->numFaceVertices - 1; + for (int vertIdx = 1; vertIdx < maxVert; ++vertIdx) + { + const SVECTOR *v0 = &vecs[0]; + const SVECTOR *v1 = &vecs[vertIdx]; + const SVECTOR *v2 = &vecs[vertIdx + 1]; + + // Naively draw the triangle with GTE, nothing special or optimized about this + gte_ldv3(v0, v1, v2); + gte_rtpt(); // Rotation, translation, perspective projection + + // Normal clipping for backface culling + gte_nclip(); + gte_stopz(&p); + if (p < 0) + continue; + + // Average Z for depth sorting and culling + gte_avsz3(); + gte_stotz(&p); + unsigned short depth = p >> 2; + if (depth <= 0 || depth >= OTLEN) + continue; + + // Draw a flat-shaded untextured colored triangle + POLY_G3 *poly = (POLY_G3*)mem_prim(sizeof(POLY_G3)); + if (poly == NULL) + break; + + setPolyG3(poly); + gte_stsxy3_g3(poly); + + poly->r0 = poly->g0 = poly->b0 = (uint8_t)v0->pad; + poly->r1 = poly->g1 = poly->b1 = (uint8_t)v1->pad; + poly->r2 = poly->g2 = poly->b2 = (uint8_t)v2->pad; + + addPrim(curOT + depth, poly); + ++polyCount; + } +} + +static inline void drawface_triangle_strip(const ps1bsp_face_t *face, SVECTOR *vecs) +{ + int p; + + // Draw the face as a triangle strip + const SVECTOR *v0, *v1, *v2; + const SVECTOR *head = vecs; + const SVECTOR *tail = vecs + face->numFaceVertices; + u_char reverse = 0; + + v2 = head++; // Initialize first vertex to index 0 and set head to index 1 + + u_char numTris = face->numFaceVertices - 2; + for (u_char triIdx = 0; triIdx < numTris; ++triIdx) + { + if (reverse ^= 1) + { + v0 = v2; + v1 = head; + v2 = --tail; + } + else + { + v0 = v1; + v1 = ++head; + v2 = tail; + } + + // Naively draw the triangle with GTE, nothing special or optimized about this + gte_ldv3(v0, v1, v2); + gte_rtpt(); // Rotation, translation, perspective projection + + // Normal clipping for backface culling + gte_nclip(); + gte_stopz(&p); + if (p < 0) + continue; + + // Average Z for depth sorting and culling + gte_avsz3(); + gte_stotz(&p); + unsigned short depth = p >> 2; + if (depth <= 0 || depth >= OTLEN) + continue; + + // Draw a flat-shaded untextured colored triangle + POLY_G3 *poly = (POLY_G3*)mem_prim(sizeof(POLY_G3)); + if (poly == NULL) + break; + + setPolyG3(poly); + gte_stsxy3_g3(poly); + + poly->r0 = poly->g0 = poly->b0 = (uint8_t)v0->pad; + poly->r1 = poly->g1 = poly->b1 = (uint8_t)v1->pad; + poly->r2 = poly->g2 = poly->b2 = (uint8_t)v2->pad; + + addPrim(curOT + depth, poly); + ++polyCount; + } +} + +static inline void drawface_quad_strip(const ps1bsp_face_t *face, SVECTOR *vecs) +{ + int p; + + // Draw the face as a quad strip + const SVECTOR *v0, *v1, *v2, *v3; + const SVECTOR *head = vecs; + const SVECTOR *tail = vecs + face->numFaceVertices; + + // Initialize the first two vertices + v2 = --tail; + v3 = head++; + + // Normally a quad strip would have (N-2)/2 quads, but we might end up with a sole triangle at the end which will be drawn as a collapsed quad + u_char numQuads = (face->numFaceVertices - 1) / 2; + for (u_char quadIdx = 0; quadIdx < numQuads; ++quadIdx) + { + v0 = v2; + v1 = v3; + v2 = --tail; + v3 = head++; + + // Naively draw the quad with GTE, nothing special or optimized about this + gte_ldv3(v0, v1, v2); + gte_rtpt(); // Rotation, translation, perspective projection + + // Normal clipping for backface culling (TODO: should be necessary only once per face, using plane normal & camera direction) + gte_nclip(); + gte_stopz(&p); + if (p < 0) + continue; + + // Average Z for depth sorting and culling + gte_avsz3(); + gte_stotz(&p); + unsigned short depth = p >> 2; + if (depth <= 0 || depth >= OTLEN) + continue; + + // Draw a flat-shaded untextured colored triangle + POLY_G4 *poly = (POLY_G4*)mem_prim(sizeof(POLY_G4)); + if (poly == NULL) + break; + + setPolyG4(poly); + gte_stsxy0(&poly->x0); + gte_stsxy1(&poly->x1); + gte_stsxy2(&poly->x2); + + // Transform the fourth vertex to complete the quad + gte_ldv0(v3); + gte_rtps(); + gte_stsxy(&poly->x3); + + poly->r0 = poly->g0 = poly->b0 = (uint8_t)v0->pad; + poly->r1 = poly->g1 = poly->b1 = (uint8_t)v1->pad; + poly->r2 = poly->g2 = poly->b2 = (uint8_t)v2->pad; + poly->r3 = poly->g3 = poly->b3 = (uint8_t)v3->pad; + + addPrim(curOT + depth, poly); + ++polyCount; + } +} + void world_draw(const world_t *world) { int p; @@ -63,64 +235,9 @@ void world_draw(const world_t *world) vecs[vertIdx].pad = vert->baseLight; } - // Draw the face as a quad strip - const SVECTOR *v0, *v1, *v2, *v3; - const SVECTOR *head = vecs; - const SVECTOR *tail = vecs + face->numFaceVertices; - - // Initialize the first two vertices - v2 = --tail; - v3 = head++; - - // Normally a quad strip would have (N-2)/2 quads, but we might end up with a sole triangle at the end which will be drawn as a collapsed quad - u_char numQuads = (face->numFaceVertices - 1) / 2; - for (u_char quadIdx = 0; quadIdx < numQuads; ++quadIdx) - { - v0 = v2; - v1 = v3; - v2 = --tail; - v3 = head++; - - // Naively draw the quad with GTE, nothing special or optimized about this - gte_ldv3(v0, v1, v2); - gte_rtpt(); // Rotation, translation, perspective projection - - // Normal clipping for backface culling (TODO: should be necessary only once per face, using plane normal & camera direction) - gte_nclip(); - gte_stopz(&p); - if (p < 0) - continue; - - // Average Z for depth sorting and culling - gte_avsz3(); - gte_stotz(&p); - unsigned short depth = p >> 2; - if (depth <= 0 || depth >= OTLEN) - continue; - - // Draw a flat-shaded untextured colored triangle - POLY_G4 *poly = (POLY_G4*)mem_prim(sizeof(POLY_G4)); - if (poly == NULL) - break; - - setPolyG4(poly); - - gte_stsxy0(&poly->x0); - gte_stsxy1(&poly->x1); - gte_stsxy2(&poly->x2); - - // Transform the fourth vertex to complete the quad - gte_ldv0(v3); - gte_rtps(); - gte_stsxy(&poly->x3); - - poly->r0 = poly->g0 = poly->b0 = (uint8_t)v0->pad; - poly->r1 = poly->g1 = poly->b1 = (uint8_t)v1->pad; - poly->r2 = poly->g2 = poly->b2 = (uint8_t)v2->pad; - poly->r3 = poly->g3 = poly->b3 = (uint8_t)v3->pad; - - addPrim(curOT + depth, poly); - ++polyCount; - } + if (face->numFaceVertices == 3) + drawface_triangle_fan(face, vecs); + else + drawface_quad_strip(face, vecs); } }