#include <stdio.h>
-#include <math.h>
+#include <stdlib.h>
#include <string.h>
+#include <math.h>
+#include <assert.h>
#include "3dgfx.h"
#include "polyfill.h"
+#include "inttypes.h"
#define STACK_SIZE 8
typedef float g3d_matrix[16];
+#define MAX_VBUF_SIZE 256
+
struct g3d_state {
unsigned int opt;
+ int frontface;
g3d_matrix mat[G3D_NUM_MATRICES][STACK_SIZE];
int mtop[G3D_NUM_MATRICES];
+ int mmode;
+
+ g3d_matrix norm_mat;
int width, height;
void *pixels;
static void xform4_vec3(const float *mat, float *vec);
static void xform3_vec3(const float *mat, float *vec);
-static void proc_vertex(struct pvertex *res, const struct g3d_vertex *vert, int space);
+static void shade(struct g3d_vertex *v);
-static struct g3d_state st;
+static struct g3d_state *st;
static const float idmat[] = {
1, 0, 0, 0,
0, 1, 0, 0,
0, 0, 0, 1
};
-void g3d_init(void)
+int g3d_init(void)
{
int i;
- memset(&st, 0, sizeof st);
+ if(!(st = calloc(1, sizeof *st))) {
+ fprintf(stderr, "failed to allocate G3D context\n");
+ return -1;
+ }
for(i=0; i<G3D_NUM_MATRICES; i++) {
- g3d_set_matrix(i, 0);
+ g3d_matrix_mode(i);
+ g3d_load_identity();
}
+ return 0;
+}
+
+void g3d_destroy(void)
+{
+ free(st);
}
void g3d_framebuffer(int width, int height, void *pixels)
{
- st.width = width;
- st.height = height;
- st.pixels = pixels;
+ st->width = width;
+ st->height = height;
+ st->pixels = pixels;
}
void g3d_enable(unsigned int opt)
{
- st.opt |= opt;
+ st->opt |= opt;
}
void g3d_disable(unsigned int opt)
{
- st.opt &= ~opt;
+ st->opt &= ~opt;
}
void g3d_setopt(unsigned int opt, unsigned int mask)
{
- st.opt = (st.opt & ~mask) | (opt & mask);
+ st->opt = (st->opt & ~mask) | (opt & mask);
}
unsigned int g3d_getopt(unsigned int mask)
{
- return st.opt & mask;
+ return st->opt & mask;
}
-void g3d_set_matrix(int which, const float *m)
+void g3d_front_face(unsigned int order)
{
- int top = st.mtop[which];
+ st->frontface = order;
+}
- if(!m) m = idmat;
- memcpy(st.mat[which][top], m, 16 * sizeof(float));
+void g3d_matrix_mode(int mmode)
+{
+ st->mmode = mmode;
+}
+
+void g3d_load_identity(void)
+{
+ int top = st->mtop[st->mmode];
+ memcpy(st->mat[st->mmode][top], idmat, 16 * sizeof(float));
+}
+
+void g3d_load_matrix(const float *m)
+{
+ int top = st->mtop[st->mmode];
+ memcpy(st->mat[st->mmode][top], m, 16 * sizeof(float));
}
#define M(i,j) (((i) << 2) + (j))
-void g3d_mult_matrix(int which, const float *m2)
+void g3d_mult_matrix(const float *m2)
{
- int i, j, top = st.mtop[which];
+ int i, j, top = st->mtop[st->mmode];
float m1[16];
- float *dest = st.mat[which][top];
+ float *dest = st->mat[st->mmode][top];
memcpy(m1, dest, sizeof m1);
}
}
-void g3d_push_matrix(int which)
+void g3d_push_matrix(void)
{
- int top = st.mtop[which];
+ int top = st->mtop[st->mmode];
if(top >= G3D_NUM_MATRICES) {
fprintf(stderr, "g3d_push_matrix overflow\n");
return;
}
- memcpy(st.mat[which][top + 1], st.mat[which][top], 16 * sizeof(float));
- st.mtop[which] = top + 1;;
+ memcpy(st->mat[st->mmode][top + 1], st->mat[st->mmode][top], 16 * sizeof(float));
+ st->mtop[st->mmode] = top + 1;
}
-void g3d_pop_matrix(int which)
+void g3d_pop_matrix(void)
{
- if(st.mtop[which] <= 0) {
+ if(st->mtop[st->mmode] <= 0) {
fprintf(stderr, "g3d_pop_matrix underflow\n");
return;
}
- --st.mtop[which];
+ --st->mtop[st->mmode];
}
-void g3d_translate(int which, float x, float y, float z)
+void g3d_translate(float x, float y, float z)
{
float m[] = {1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1};
m[12] = x;
m[13] = y;
m[14] = z;
- g3d_mult_matrix(which, m);
+ g3d_mult_matrix(m);
}
-void g3d_rotate(int which, float deg, float x, float y, float z)
+void g3d_rotate(float deg, float x, float y, float z)
{
float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
m[2] = x * z * one_minus_cosa - y * sina;
m[6] = y * z * one_minus_cosa + x * sina;
m[10] = nzsq + (1.0 - nzsq) * cosa;
+ m[15] = 1.0f;
- g3d_mult_matrix(which, m);
+ g3d_mult_matrix(m);
}
-void g3d_scale(int which, float x, float y, float z)
+void g3d_scale(float x, float y, float z)
{
float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
m[0] = x;
m[5] = y;
m[10] = z;
- g3d_mult_matrix(which, m);
+ m[15] = 1.0f;
+ g3d_mult_matrix(m);
}
-void g3d_ortho(int which, float left, float right, float bottom, float top, float znear, float zfar)
+void g3d_ortho(float left, float right, float bottom, float top, float znear, float zfar)
{
float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
m[13] = -(top + bottom) / dy;
m[14] = -(zfar + znear) / dz;
- g3d_mult_matrix(which, m);
+ g3d_mult_matrix(m);
}
-void g3d_frustum(int which, float left, float right, float bottom, float top, float nr, float fr)
+void g3d_frustum(float left, float right, float bottom, float top, float nr, float fr)
{
float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
m[11] = -1.0f;
m[14] = d;
- g3d_mult_matrix(which, m);
+ g3d_mult_matrix(m);
}
-void g3d_perspective(int which, float vfov_deg, float aspect, float znear, float zfar)
+void g3d_perspective(float vfov_deg, float aspect, float znear, float zfar)
{
float m[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
m[11] = -1.0f;
m[14] = 2.0f * znear * zfar / range;
- g3d_mult_matrix(which, m);
+ g3d_mult_matrix(m);
}
-void g3d_draw(int prim, int space, const struct g3d_vertex *varr, int varr_size)
+#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)
+
+void g3d_draw(int prim, const struct g3d_vertex *varr, int varr_size)
{
int i;
- int vnum = prim; /* primitive vertex counts correspond to the enum values */
+ struct pvertex pv[4];
+ struct g3d_vertex v[4];
+ int vnum = prim; /* primitive vertex counts correspond to enum values */
+ int mvtop = st->mtop[G3D_MODELVIEW];
+ int ptop = st->mtop[G3D_PROJECTION];
+
+ /* 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) {
- struct pvertex pv[4];
+ varr_size -= vnum;
for(i=0; i<vnum; i++) {
- proc_vertex(pv + i, varr++, space);
+ v[i] = *varr++;
+
+ xform4_vec3(st->mat[G3D_MODELVIEW][mvtop], &v[i].x);
+ xform3_vec3(st->norm_mat, &v[i].nx);
+
+ if(st->opt & G3D_LIGHTING) {
+ shade(v + i);
+ }
+ xform4_vec3(st->mat[G3D_PROJECTION][ptop], &v[i].x);
}
- polyfill_wire(pv, vnum);
+ /* TODO clipping */
- varr_size -= vnum;
+ for(i=0; i<vnum; i++) {
+ if(v[i].w != 0.0f) {
+ v[i].x /= v[i].w;
+ v[i].y /= v[i].w;
+ /*v[i].z /= v[i].w;*/
+ }
+
+ /* 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;
+
+ /* 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);
+ /* 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);
+ /* pass the color through as is */
+ pv[i].r = v[i].r;
+ pv[i].g = v[i].g;
+ pv[i].b = v[i].b;
+ }
+
+ /* backface culling */
+ if(vnum > 2 && st->opt & G3D_CULL_FACE) {
+ int32_t ax = pv[1].x - pv[0].x;
+ 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);
+ int sign = (cross_z >> 31) & 1;
+
+ if(!(sign ^ st->frontface)) {
+ continue; /* back-facing */
+ }
+ }
+
+ polyfill_flat(pv, vnum);
}
}
vec[2] = z;
}
-#define VEC3(v, x, y, z) do { v[0] = x; v[1] = y; v[2] = z; } while(0)
-#define VEC4(v, x, y, z, w) do { v[0] = x; v[1] = y; v[2] = z; v[3] = w; } while(0)
-
-static void proc_vertex(struct pvertex *res, const struct g3d_vertex *vert, int space)
+static void shade(struct g3d_vertex *v)
{
- float pos[4];
- float norm[3];
- float color[3];
- int mvtop = st.mtop[G3D_MODELVIEW];
- int ptop = st.mtop[G3D_PROJECTION];
- g3d_matrix norm_mat;
-
- VEC4(pos, vert->x, vert->y, vert->z, 1.0f);
- VEC3(norm, vert->nx, vert->ny, vert->nz);
-
- switch(space) {
- case G3D_LOCAL_SPACE:
- memcpy(norm_mat, st.mat[G3D_MODELVIEW][mvtop], 16 * sizeof(float));
- norm_mat[12] = norm_mat[13] = norm_mat[14] = 0.0f;
-
- xform4_vec3(pos, st.mat[G3D_MODELVIEW][mvtop]);
- xform3_vec3(norm, norm_mat);
-
- case G3D_VIEW_SPACE:
- if(st.opt & G3D_LIGHTING) {
- /* TODO lighting */
- color[0] = vert->r;
- color[1] = vert->g;
- color[2] = vert->b;
- }
- xform4_vec3(pos, st.mat[G3D_PROJECTION][ptop]);
-
- case G3D_CLIP_SPACE:
- /* TODO clipping */
- if(pos[3] != 0.0f) {
- pos[0] /= pos[3];
- pos[1] /= pos[3];
- pos[2] /= pos[3];
- }
-
- case G3D_SCREEN_SPACE:
- pos[0] = (pos[0] * 0.5 + 0.5) * (float)st.width;
- pos[1] = (0.5 - pos[0] * 0.5) * (float)st.height;
-
- case G3D_PIXEL_SPACE:
- break;
- }
-
- /* convert pos to 24.8 fixed point */
- res->x = (int32_t)(pos[0] * 256.0f);
- res->y = (int32_t)(pos[1] * 256.0f);
-
- /* convert tex coords to 16.16 fixed point */
- res->u = (int32_t)(vert->u * 65536.0f);
- res->v = (int32_t)(vert->v * 65536.0f);
-
- /* pass color through as is */
- res->r = color[0];
- res->g = color[1];
- res->b = color[2];
+ v->r = v->g = v->b = 255;
}
projects / dosdemo / blobdiff