backported fixes from rtxon
[dosdemo] / src / 3dgfx.c
index 49b4c2c..a642c1e 100644 (file)
@@ -3,18 +3,41 @@
 #include <string.h>
 #include <math.h>
 #include <assert.h>
+#if defined(__WATCOMC__) || defined(_MSC_VER) || defined(__DJGPP__)
+#include <malloc.h>
+#else
+#include <alloca.h>
+#endif
 #include "3dgfx.h"
+#include "gfxutil.h"
 #include "polyfill.h"
+#include "polyclip.h"
 #include "inttypes.h"
+#include "demo.h"
+#include "util.h"
 
 #define STACK_SIZE     8
 typedef float g3d_matrix[16];
 
-#define MAX_VBUF_SIZE  256
+#define MAX_LIGHTS             4
+
+#define IMM_VBUF_SIZE  256
+
+struct light {
+       float x, y, z;
+       float r, g, b;
+};
+
+struct material {
+       float kd[3];
+       float ks[3];
+       float shin;
+};
 
 struct g3d_state {
        unsigned int opt;
        int frontface;
+       int fill_mode;
 
        g3d_matrix mat[G3D_NUM_MATRICES][STACK_SIZE];
        int mtop[G3D_NUM_MATRICES];
@@ -22,10 +45,23 @@ struct g3d_state {
 
        g3d_matrix norm_mat;
 
+       float ambient[3];
+       struct light lt[MAX_LIGHTS];
+       struct material mtl;
+
        int width, height;
-       void *pixels;
+       uint16_t *pixels;
+
+       int vport[4];
+
+       /* immediate mode */
+       int imm_prim;
+       int imm_numv, imm_pcount;
+       struct g3d_vertex imm_curv;
+       struct g3d_vertex imm_vbuf[IMM_VBUF_SIZE];
 };
 
+static void imm_flush(void);
 static void xform4_vec3(const float *mat, float *vec);
 static void xform3_vec3(const float *mat, float *vec);
 static void shade(struct g3d_vertex *v);
@@ -46,11 +82,20 @@ int g3d_init(void)
                fprintf(stderr, "failed to allocate G3D context\n");
                return -1;
        }
+       st->opt = G3D_CLIP_FRUSTUM;
+       st->fill_mode = POLYFILL_FLAT;
 
        for(i=0; i<G3D_NUM_MATRICES; i++) {
                g3d_matrix_mode(i);
                g3d_load_identity();
        }
+
+       for(i=0; i<MAX_LIGHTS; i++) {
+               g3d_light_color(i, 1, 1, 1);
+       }
+       g3d_light_ambient(0.1, 0.1, 0.1);
+
+       g3d_mtl_diffuse(1, 1, 1);
        return 0;
 }
 
@@ -64,6 +109,27 @@ void g3d_framebuffer(int width, int height, void *pixels)
        st->width = width;
        st->height = height;
        st->pixels = pixels;
+
+       pfill_fb.pixels = pixels;
+       pfill_fb.width = width;
+       pfill_fb.height = height;
+
+       g3d_viewport(0, 0, width, height);
+}
+
+/* set the framebuffer pointer, without resetting the size */
+void g3d_framebuffer_addr(void *pixels)
+{
+       st->pixels = pixels;
+       pfill_fb.pixels = pixels;
+}
+
+void g3d_viewport(int x, int y, int w, int h)
+{
+       st->vport[0] = x;
+       st->vport[1] = y;
+       st->vport[2] = w;
+       st->vport[3] = h;
 }
 
 void g3d_enable(unsigned int opt)
@@ -91,6 +157,11 @@ void g3d_front_face(unsigned int order)
        st->frontface = order;
 }
 
+void g3d_polygon_mode(int pmode)
+{
+       st->fill_mode = pmode;
+}
+
 void g3d_matrix_mode(int mmode)
 {
        st->mmode = mmode;
@@ -251,31 +322,115 @@ void g3d_perspective(float vfov_deg, float aspect, float znear, float zfar)
        g3d_mult_matrix(m);
 }
 
-#define CROSS(res, a, b) \
-       do { \
-               (res)[0] = (a)[1] * (b)[2] - (a)[2] * (b)[1]; \
-               (res)[1] = (a)[2] * (b)[0] - (a)[0] * (b)[2]; \
-               (res)[2] = (a)[0] * (b)[1] - (a)[1] * (b)[0]; \
-       } while(0)
+const float *g3d_get_matrix(int which, float *m)
+{
+       int top = st->mtop[which];
+
+       if(m) {
+               memcpy(m, st->mat[which][top], 16 * sizeof(float));
+       }
+       return st->mat[which][top];
+}
+
+void g3d_light_pos(int idx, float x, float y, float z)
+{
+       int mvtop = st->mtop[G3D_MODELVIEW];
+
+       st->lt[idx].x = x;
+       st->lt[idx].y = y;
+       st->lt[idx].z = z;
+
+       xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &st->lt[idx].x);
+}
+
+void g3d_light_color(int idx, float r, float g, float b)
+{
+       st->lt[idx].r = r;
+       st->lt[idx].g = g;
+       st->lt[idx].b = b;
+}
+
+void g3d_light_ambient(float r, float g, float b)
+{
+       st->ambient[0] = r;
+       st->ambient[1] = g;
+       st->ambient[2] = b;
+}
+
+void g3d_mtl_diffuse(float r, float g, float b)
+{
+       st->mtl.kd[0] = r;
+       st->mtl.kd[1] = g;
+       st->mtl.kd[2] = b;
+}
+
+void g3d_mtl_specular(float r, float g, float b)
+{
+       st->mtl.ks[0] = r;
+       st->mtl.ks[1] = g;
+       st->mtl.ks[2] = b;
+}
+
+void g3d_mtl_shininess(float shin)
+{
+       st->mtl.shin = shin;
+}
+
+static INLINE int calc_shift(unsigned int x)
+{
+       int res = -1;
+       while(x) {
+               x >>= 1;
+               ++res;
+       }
+       return res;
+}
+
+static INLINE int calc_mask(unsigned int x)
+{
+       return x - 1;
+}
+
+void g3d_set_texture(int xsz, int ysz, void *pixels)
+{
+       pfill_tex.pixels = pixels;
+       pfill_tex.width = xsz;
+       pfill_tex.height = ysz;
+
+       pfill_tex.xshift = calc_shift(xsz);
+       pfill_tex.yshift = calc_shift(ysz);
+       pfill_tex.xmask = calc_mask(xsz);
+       pfill_tex.ymask = calc_mask(ysz);
+}
 
 void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
 {
-       int i;
-       struct pvertex pv[4];
-       struct g3d_vertex v[4];
-       int vnum = prim; /* primitive vertex counts correspond to enum values */
+       g3d_draw_indexed(prim, varr, varr_size, 0, 0);
+}
+
+void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
+               const uint16_t *iarr, int iarr_size)
+{
+       int i, j, vnum, nfaces;
+       struct pvertex pv[16];
+       struct g3d_vertex v[16];
        int mvtop = st->mtop[G3D_MODELVIEW];
        int ptop = st->mtop[G3D_PROJECTION];
+       struct g3d_vertex *tmpv;
+
+       tmpv = alloca(prim * 6 * sizeof *tmpv);
 
        /* calc the normal matrix */
        memcpy(st->norm_mat, st->mat[G3D_MODELVIEW][mvtop], 16 * sizeof(float));
        st->norm_mat[12] = st->norm_mat[13] = st->norm_mat[14] = 0.0f;
 
-       while(varr_size >= vnum) {
-               varr_size -= vnum;
+       nfaces = (iarr ? iarr_size : varr_size) / prim;
+
+       for(j=0; j<nfaces; j++) {
+               vnum = prim;    /* reset vnum for each iteration */
 
                for(i=0; i<vnum; i++) {
-                       v[i] = *varr++;
+                       v[i] = iarr ? varr[*iarr++] : *varr++;
 
                        xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &v[i].x);
                        xform3_vec3(st->norm_mat, &v[i].nx);
@@ -283,10 +438,27 @@ void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
                        if(st->opt & G3D_LIGHTING) {
                                shade(v + i);
                        }
+                       if(st->opt & G3D_TEXTURE_GEN) {
+                               v[i].u = v[i].nx * 0.5 + 0.5;
+                               v[i].v = v[i].ny * 0.5 + 0.5;
+                       }
                        xform4_vec3(st->mat[G3D_PROJECTION][ptop], &v[i].x);
                }
 
-               /* TODO clipping */
+               /* clipping */
+               if(st->opt & G3D_CLIP_FRUSTUM) {
+                       for(i=0; i<6; i++) {
+                               memcpy(tmpv, v, vnum * sizeof *v);
+
+                               if(clip_frustum(v, &vnum, tmpv, vnum, i) < 0) {
+                                       /* polygon completely outside of view volume. discard */
+                                       vnum = 0;
+                                       break;
+                               }
+                       }
+
+                       if(!vnum) continue;
+               }
 
                for(i=0; i<vnum; i++) {
                        if(v[i].w != 0.0f) {
@@ -296,19 +468,20 @@ void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
                        }
 
                        /* viewport transformation */
-                       v[i].x = (v[i].x * 0.5f + 0.5f) * (float)st->width;
-                       v[i].y = (0.5f - v[i].y * 0.5f) * (float)st->height;
+                       v[i].x = (v[i].x * 0.5f + 0.5f) * (float)st->vport[2] + st->vport[0];
+                       v[i].y = (0.5f - v[i].y * 0.5f) * (float)st->vport[3] + st->vport[1];
 
                        /* convert pos to 24.8 fixed point */
-                       pv[i].x = (int32_t)(v[i].x * 256.0f);
-                       pv[i].y = (int32_t)(v[i].y * 256.0f);
+                       pv[i].x = cround64(v[i].x * 256.0f);
+                       pv[i].y = cround64(v[i].y * 256.0f);
                        /* convert tex coords to 16.16 fixed point */
-                       pv[i].u = (int32_t)(v[i].u * 65536.0f);
-                       pv[i].v = (int32_t)(v[i].v * 65536.0f);
+                       pv[i].u = cround64(v[i].u * 65536.0f);
+                       pv[i].v = cround64(v[i].v * 65536.0f);
                        /* pass the color through as is */
                        pv[i].r = v[i].r;
                        pv[i].g = v[i].g;
                        pv[i].b = v[i].b;
+                       pv[i].a = v[i].a;
                }
 
                /* backface culling */
@@ -317,7 +490,7 @@ void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
                        int32_t ay = pv[1].y - pv[0].y;
                        int32_t bx = pv[2].x - pv[0].x;
                        int32_t by = pv[2].y - pv[0].y;
-                       int32_t cross_z = ax * (by >> 8) - ay * (bx >> 8);
+                       int32_t cross_z = (ax >> 4) * (by >> 4) - (ay >> 4) * (bx >> 4);
                        int sign = (cross_z >> 31) & 1;
 
                        if(!(sign ^ st->frontface)) {
@@ -325,10 +498,120 @@ void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
                        }
                }
 
-               polyfill_flat(pv, vnum);
+               switch(vnum) {
+               case 1:
+                       if(st->opt & G3D_BLEND) {
+                               int r, g, b;
+                               int inv_alpha = 255 - pv[0].a;
+                               uint16_t *dest = st->pixels + (pv[0].y >> 8) * st->width + (pv[0].x >> 8);
+                               r = ((int)pv[0].r * pv[0].a + UNPACK_R16(*dest) * inv_alpha) >> 8;
+                               g = ((int)pv[0].g * pv[0].a + UNPACK_G16(*dest) * inv_alpha) >> 8;
+                               b = ((int)pv[0].b * pv[0].a + UNPACK_B16(*dest) * inv_alpha) >> 8;
+                               *dest++ = PACK_RGB16(r, g, b);
+                       } else {
+                               uint16_t *dest = st->pixels + (pv[0].y >> 8) * st->width + (pv[0].x >> 8);
+                               *dest = PACK_RGB16(pv[0].r, pv[0].g, pv[0].b);
+                       }
+                       break;
+
+               case 2:
+                       /* TODO: draw line */
+                       break;
+
+               default:
+                       polyfill(st->fill_mode, pv, vnum);
+               }
+       }
+}
+
+void g3d_begin(int prim)
+{
+       st->imm_prim = prim;
+       st->imm_pcount = prim;
+       st->imm_numv = 0;
+}
+
+void g3d_end(void)
+{
+       imm_flush();
+}
+
+static void imm_flush(void)
+{
+       int numv = st->imm_numv;
+       st->imm_numv = 0;
+       g3d_draw_indexed(st->imm_prim, st->imm_vbuf, numv, 0, 0);
+}
+
+void g3d_vertex(float x, float y, float z)
+{
+       struct g3d_vertex *vptr = st->imm_vbuf + st->imm_numv++;
+       *vptr = st->imm_curv;
+       vptr->x = x;
+       vptr->y = y;
+       vptr->z = z;
+       vptr->w = 1.0f;
+
+       if(!--st->imm_pcount) {
+               if(st->imm_numv >= IMM_VBUF_SIZE - st->imm_prim) {
+                       imm_flush();
+               }
+               st->imm_pcount = st->imm_prim;
        }
 }
 
+void g3d_normal(float x, float y, float z)
+{
+       st->imm_curv.nx = x;
+       st->imm_curv.ny = y;
+       st->imm_curv.nz = z;
+}
+
+void g3d_color3b(unsigned char r, unsigned char g, unsigned char b)
+{
+       st->imm_curv.r = r;
+       st->imm_curv.g = g;
+       st->imm_curv.b = b;
+       st->imm_curv.a = 255;
+}
+
+void g3d_color4b(unsigned char r, unsigned char g, unsigned char b, unsigned char a)
+{
+       st->imm_curv.r = r;
+       st->imm_curv.g = g;
+       st->imm_curv.b = b;
+       st->imm_curv.a = a;
+}
+
+void g3d_color3f(float r, float g, float b)
+{
+       int ir = r * 255.0f;
+       int ig = g * 255.0f;
+       int ib = b * 255.0f;
+       st->imm_curv.r = ir > 255 ? 255 : ir;
+       st->imm_curv.g = ig > 255 ? 255 : ig;
+       st->imm_curv.b = ib > 255 ? 255 : ib;
+       st->imm_curv.a = 255;
+}
+
+void g3d_color4f(float r, float g, float b, float a)
+{
+       int ir = r * 255.0f;
+       int ig = g * 255.0f;
+       int ib = b * 255.0f;
+       int ia = a * 255.0f;
+       st->imm_curv.r = ir > 255 ? 255 : ir;
+       st->imm_curv.g = ig > 255 ? 255 : ig;
+       st->imm_curv.b = ib > 255 ? 255 : ib;
+       st->imm_curv.a = ia > 255 ? 255 : ia;
+}
+
+void g3d_texcoord(float u, float v)
+{
+       st->imm_curv.u = u;
+       st->imm_curv.v = v;
+}
+
 static void xform4_vec3(const float *mat, float *vec)
 {
        float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2] + mat[12];
@@ -353,7 +636,53 @@ static void xform3_vec3(const float *mat, float *vec)
        vec[2] = z;
 }
 
+#define NORMALIZE(v) \
+       do { \
+               float len = sqrt(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]); \
+               if(len != 0.0) { \
+                       float s = 1.0 / len; \
+                       v[0] *= s; \
+                       v[1] *= s; \
+                       v[2] *= s; \
+               } \
+       } while(0)
+
 static void shade(struct g3d_vertex *v)
 {
-       v->r = v->g = v->b = 255;
+       int i, r, g, b;
+       float color[3];
+
+       color[0] = st->ambient[0] * st->mtl.kd[0];
+       color[1] = st->ambient[1] * st->mtl.kd[1];
+       color[2] = st->ambient[2] * st->mtl.kd[2];
+
+       for(i=0; i<MAX_LIGHTS; i++) {
+               float ldir[3];
+               float ndotl;
+
+               if(!(st->opt & (G3D_LIGHT0 << i))) {
+                       continue;
+               }
+
+               ldir[0] = st->lt[i].x - v->x;
+               ldir[1] = st->lt[i].y - v->y;
+               ldir[2] = st->lt[i].z - v->z;
+               NORMALIZE(ldir);
+
+               if((ndotl = v->nx * ldir[0] + v->ny * ldir[1] + v->nz * ldir[2]) < 0.0f) {
+                       ndotl = 0.0f;
+               }
+
+               color[0] += st->mtl.kd[0] * st->lt[i].r * ndotl;
+               color[1] += st->mtl.kd[1] * st->lt[i].g * ndotl;
+               color[2] += st->mtl.kd[2] * st->lt[i].b * ndotl;
+       }
+
+       r = cround64(color[0] * 255.0);
+       g = cround64(color[1] * 255.0);
+       b = cround64(color[2] * 255.0);
+
+       v->r = r > 255 ? 255 : r;
+       v->g = g > 255 ? 255 : g;
+       v->b = b > 255 ? 255 : b;
 }