+#include <stdio.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 struct g3d_state st;
+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);
+
+static struct g3d_state *st;
+static const float idmat[] = {
+ 1, 0, 0, 0,
+ 0, 1, 0, 0,
+ 0, 0, 1, 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_front_face(unsigned int order)
+{
+ st->frontface = order;
}
-void g3d_set_matrix(int which, const float *m)
+void g3d_matrix_mode(int mmode)
{
- int top = st.mtop[which];
- memcpy(st.mat[which][top], m, 16 * sizeof(float));
+ 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);
}
}
}
-/* TODO continue ... */
+
+void g3d_push_matrix(void)
+{
+ int top = st->mtop[st->mmode];
+ if(top >= G3D_NUM_MATRICES) {
+ fprintf(stderr, "g3d_push_matrix overflow\n");
+ return;
+ }
+ 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(void)
+{
+ if(st->mtop[st->mmode] <= 0) {
+ fprintf(stderr, "g3d_pop_matrix underflow\n");
+ return;
+ }
+ --st->mtop[st->mmode];
+}
+
+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(m);
+}
+
+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};
+
+ float angle = M_PI * deg / 180.0f;
+ float sina = sin(angle);
+ float cosa = cos(angle);
+ float one_minus_cosa = 1.0f - cosa;
+ float nxsq = x * x;
+ float nysq = y * y;
+ float nzsq = z * z;
+
+ m[0] = nxsq + (1.0f - nxsq) * cosa;
+ m[4] = x * y * one_minus_cosa - z * sina;
+ m[8] = x * z * one_minus_cosa + y * sina;
+ m[1] = x * y * one_minus_cosa + z * sina;
+ m[5] = nysq + (1.0 - nysq) * cosa;
+ m[9] = y * z * one_minus_cosa - x * sina;
+ 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(m);
+}
+
+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;
+ m[15] = 1.0f;
+ g3d_mult_matrix(m);
+}
+
+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};
+
+ float dx = right - left;
+ float dy = top - bottom;
+ float dz = zfar - znear;
+
+ m[0] = 2.0 / dx;
+ m[5] = 2.0 / dy;
+ m[10] = -2.0 / dz;
+ m[12] = -(right + left) / dx;
+ m[13] = -(top + bottom) / dy;
+ m[14] = -(zfar + znear) / dz;
+
+ g3d_mult_matrix(m);
+}
+
+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};
+
+ float dx = right - left;
+ float dy = top - bottom;
+ float dz = fr - nr;
+
+ float a = (right + left) / dx;
+ float b = (top + bottom) / dy;
+ float c = -(fr + nr) / dz;
+ float d = -2.0 * fr * nr / dz;
+
+ m[0] = 2.0 * nr / dx;
+ m[5] = 2.0 * nr / dy;
+ m[8] = a;
+ m[9] = b;
+ m[10] = c;
+ m[11] = -1.0f;
+ m[14] = d;
+
+ g3d_mult_matrix(m);
+}
+
+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};
+
+ float vfov = M_PI * vfov_deg / 180.0f;
+ float s = 1.0f / tan(vfov * 0.5f);
+ float range = znear - zfar;
+
+ m[0] = s / aspect;
+ m[5] = s;
+ m[10] = (znear + zfar) / range;
+ m[11] = -1.0f;
+ m[14] = 2.0f * znear * zfar / range;
+
+ 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)
+
+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 */
+ 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) {
+ varr_size -= vnum;
+
+ for(i=0; i<vnum; i++) {
+ 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);
+ }
+
+ /* TODO clipping */
+
+ 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);
+ }
+}
+
+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];
+ float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2] + mat[13];
+ float z = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2] + mat[14];
+ float w = mat[3] * vec[0] + mat[7] * vec[1] + mat[11] * vec[2] + mat[15];
+
+ vec[0] = x;
+ vec[1] = y;
+ vec[2] = z;
+ vec[3] = w;
+}
+
+static void xform3_vec3(const float *mat, float *vec)
+{
+ float x = mat[0] * vec[0] + mat[4] * vec[1] + mat[8] * vec[2];
+ float y = mat[1] * vec[0] + mat[5] * vec[1] + mat[9] * vec[2];
+ float z = mat[2] * vec[0] + mat[6] * vec[1] + mat[10] * vec[2];
+
+ vec[0] = x;
+ vec[1] = y;
+ vec[2] = z;
+}
+
+static void shade(struct g3d_vertex *v)
+{
+ v->r = v->g = v->b = 255;
+}
projects / dosdemo / blobdiff