X-Git-Url: http://git.mutantstargoat.com/user/nuclear/?a=blobdiff_plain;f=src%2F3dgfx.c;h=31e649d3d5174770b9ce031237e849d8e1c4d824;hb=refs%2Fheads%2Fmusic;hp=e7aabc235efd44ab1b4fe3ee2e9f5e535f6a29ec;hpb=921c229affb2b1da97d7be21d5c86ad045a6fcc3;p=dosdemo

diff --git a/src/3dgfx.c b/src/3dgfx.c
index e7aabc2..31e649d 100644
--- a/src/3dgfx.c
+++ b/src/3dgfx.c
@@ -1,71 +1,119 @@
+#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_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_set_matrix(int which, const float *m)
+void g3d_load_matrix(const float *m)
 {
-	int top = st.mtop[which];
-	memcpy(st.mat[which][top], m, 16 * sizeof(float));
+	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);
 
@@ -78,4 +126,244 @@ void g3d_mult_matrix(int which, const float *m2)
 		}
 	}
 }
-/* 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);
+}
+
+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_draw(int prim, const struct g3d_vertex *varr, int varr_size)
+{
+	g3d_draw_indexed(prim, varr, varr_size, 0, 0);
+}
+
+void g3d_draw_indexed(int prim, const struct g3d_vertex *varr, int varr_size,
+		const int16_t *iarr, int iarr_size)
+{
+	int i, j, nfaces;
+	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;
+
+	nfaces = (iarr ? iarr_size : varr_size) / vnum;
+
+	for(j=0; j<nfaces; j++) {
+
+		for(i=0; i<vnum; i++) {
+			v[i] = iarr ? varr[*iarr++] : *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;
+}