Model loading and basic lighting.

1 files changed, 267 insertions, 0 deletions

diff --git a/convmesh.c b/convmesh.c
new file mode 100644
index 0000000..e559824
--- /dev/null
+++ b/convmesh.c
@@ -0,0 +1,267 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/* px py pz nx ny nz u v */
+#define elpv 8
+
+#define safe_malloc(p, s) \
+	p = malloc(s); \
+	if (!p) { \
+		fprintf( \
+			stderr, \
+			"Out of memory.\n" \
+		); \
+		return 3; \
+	}
+
+typedef struct {
+	unsigned short p, n, t;
+} Vert;
+
+typedef struct {
+	int vc, pc, nc, tc;
+	float* p, * n, * t;
+	Vert* verts;
+} Model;
+
+int line_len(const char* line) {
+	const char* c;
+	int r = 0;
+	for (c = line; *c && *c != '\n'; c++, r++);
+	return r;
+}
+
+const char* next_line(const char* line) {
+	const char* c;
+	for (c = line; *c != '\n'; c++) {
+		if (!*c) return 0;
+	}
+	return c + 1;
+}
+
+int read_model(Model* m, const char* src) {
+	const char* line;
+	int pc = 0, nc = 0, tc = 0, vc = 0;
+	for (line = src; line; line = next_line(line)) {
+		if (line_len(line) < 6) continue;
+		if (!memcmp("vn", line, 2))
+			nc++;
+		else if (!memcmp("vt", line, 2))
+			tc++;
+		else if (!memcmp("v", line, 1))
+			pc++;
+		else if (!memcmp("f", line, 1))
+			vc++;
+	}
+	safe_malloc(m->p,     pc * 3 * sizeof *m->p);
+	safe_malloc(m->n,     nc * 3 * sizeof *m->n);
+	safe_malloc(m->t,     tc * 2 * sizeof *m->t);
+	safe_malloc(m->verts, vc * 3 * sizeof *m->verts);
+	pc =
+	nc =
+	tc = 0;
+	m->vc = 0;
+	for (line = src; line; line = next_line(line)) {
+		int idx;
+		char* end;
+		if (!memcmp("vn", line, 2)) {
+			idx = nc++;
+			m->n[idx * 3 + 0] = (float)strtod(line + 3, &end);
+			m->n[idx * 3 + 1] = (float)strtod(end, &end);
+			m->n[idx * 3 + 2] = (float)strtod(end, &end);
+		} else if (!memcmp("vt", line, 2)) {
+			idx = tc++;
+			m->t[idx * 2 + 0] = (float)strtod(line + 3, &end);
+			m->t[idx * 2 + 1] = (float)strtod(end, &end);
+		} else if (!memcmp("v", line, 1)) {
+			idx = pc++;
+			m->p[idx * 3 + 0] = (float)strtod(line + 2, &end);
+			m->p[idx * 3 + 1] = (float)strtod(end, &end);
+			m->p[idx * 3 + 2] = (float)strtod(end, &end);
+		} else if (!memcmp("f", line, 1)) {
+			idx = m->vc++;
+			m->verts[idx].p = (int)strtol(line + 1, &end, 10) - 1;
+			m->verts[idx].t = (int)strtol(end + 1, &end, 10) - 1;
+			m->verts[idx].n = (int)strtol(end + 1, &end, 10) - 1;
+			idx = m->vc++;
+			m->verts[idx].p = (int)strtol(end + 1, &end, 10) - 1;
+			m->verts[idx].t = (int)strtol(end + 1, &end, 10) - 1;
+			m->verts[idx].n = (int)strtol(end + 1, &end, 10) - 1;
+			idx = m->vc++;
+			m->verts[idx].p = (int)strtol(end + 1, &end, 10) - 1;
+			m->verts[idx].t = (int)strtol(end + 1, &end, 10) - 1;
+			m->verts[idx].n = (int)strtol(end + 1, &end, 10) - 1;
+		}
+	}
+	m->pc = pc;
+	m->nc = nc;
+	m->tc = tc;
+	return 0;
+}
+/*
+int expand_model(Model* m, float** overt, int* ovc) {
+	int i, c, o;
+	float* v;
+	c = m->vc;
+	safe_malloc(v, c * elpv * sizeof *v);
+	for (i = o = 0; i < m->vc; i++, o += elpv) {
+		v[o + 0] = m->p[m->verts[i].p * 3 + 0];
+		v[o + 1] = m->p[m->verts[i].p * 3 + 1];
+		v[o + 2] = m->p[m->verts[i].p * 3 + 2];
+		v[o + 3] = m->n[m->verts[i].n * 3 + 0];
+		v[o + 4] = m->n[m->verts[i].n * 3 + 1];
+		v[o + 5] = m->n[m->verts[i].n * 3 + 2];
+		v[o + 6] = m->t[m->verts[i].t * 2 + 0];
+		v[o + 7] = m->t[m->verts[i].t * 2 + 1];
+	}
+	*overt = v;
+	*ovc = c;
+	return 0;
+}
+
+void vert_cpy(float* dst, const float* src) {
+	int i;
+	for (i = 0; i < elpv; i++)
+		dst[i] = src[i];
+}
+
+int verts_eq(const float* a, const float* b) {
+	int i;
+#define absf(v) \
+	((v) < 0.0f? -(v): (v))
+	for (i = 0; i < elpv; i++)
+		if (absf(a[i] - b[i]) > 0.0001f)
+			return 0;
+	return 1;
+#undef absf
+}
+
+int index_model(
+	float* vert,
+	int vc,
+	float** overt,
+	unsigned short** oind,
+	int* ovc,
+	int* oic
+) {
+	float* ivert;
+	unsigned short* ind;
+	int i, ic, ivc;
+	safe_malloc(ivert, vc * elpv * sizeof *ivert);
+	safe_malloc(ind,   vc * sizeof *ind);
+	for (i = ic = ivc = 0; i < vc; i++) {
+		int j, idx;
+		for (j = 0; j < ivc; j++) {
+			if (verts_eq(&vert[i * elpv], &ivert[j * elpv])) {
+				ind[ic++] = (unsigned short)j;
+				goto cont;
+			}
+		}
+		idx = ivc++;
+		vert_cpy(&ivert[idx * elpv], &vert[i * elpv]);
+		ind[ic++] = (unsigned short)idx;
+		cont: continue;
+	}
+	*overt = ivert;
+	*oind = ind;
+	*ovc = ivc;
+	*oic = ic;
+	return 0;
+}
+
+int write_model(
+	float* vert,
+	unsigned short* ind,
+	int vc,
+	int ic,
+	FILE* f
+) {
+	int i, c;
+#define write(b, s)\
+	if (fwrite(b, 1, s, f) != s) return 42;
+	write(&vc,  4);
+	write(&ic,  4);
+	c = vc * elpv;
+	for (i = 0; i < c; i++) {
+		int fv = (int)(vert[i] * 512.0f);
+		write(&fv, 4);
+	}
+	write(ind,  ic * sizeof *ind);
+	return 0;
+}*/
+
+int write_model(
+	Model* m,
+	FILE* f
+) {
+	int i, c, pad[8] = { 0 };
+#define write(b, s)\
+	if (fwrite(b, 1, s, f) != s) return 42;
+	write(&m->vc, 4);
+	write(&m->pc, 4);
+	write(&m->nc, 4);
+	write(&m->tc, 4);
+	write(pad, 32);
+	for (i = 0, c = m->pc * 3; i < c; i++) {
+		int fv = (int)(m->p[i] * 512.0f);
+		write(&fv, 4);
+	}
+	for (i = 0, c = m->nc * 3; i < c; i++) {
+		int fv = (int)(m->n[i] * 512.0f);
+		write(&fv, 4);
+	}
+	for (i = 0, c = m->tc * 2; i < c; i++) {
+		int fv = (int)(m->t[i] * 512.0f);
+		write(&fv, 4);
+	}
+	write(m->verts, m->vc * sizeof *m->verts);
+	return 0;
+}
+
+int main(int argc, const char** argv) {
+	FILE* infile, * outfile;
+	char* src;
+	Model m;
+	int s, r;
+	if (argc < 3) {
+		fprintf(
+			stderr,
+			"Usage: %s infile outfile\n",
+			argv[0]
+		);
+		return 1;
+	}
+	infile = fopen(argv[1], "r");
+	if (!infile) {
+		fprintf(
+			stderr,
+			"Can't open %s.\n",
+			argv[1]
+		);
+		return 2;
+	}
+	fseek(infile, 0, SEEK_END);
+	s = ftell(infile);
+	rewind(infile);
+	safe_malloc(src, s + 1);
+	s = fread(src, 1, s, infile);
+	src[s] = 0;
+	if ((r = read_model(&m, src)))
+		return r;
+	free(src);
+	outfile = fopen(argv[2], "wb");
+	if (!outfile) {
+		fprintf(
+			stderr,
+			"Can't open %s.\n",
+			argv[2]
+		);
+		return 2;
+	}
+	if ((r = write_model(&m, outfile)))
+		return r;
+	fclose(infile);
+	fclose(outfile);
+	return 0;
+}