glstuff

commit 3434b95ff7c5bb581e116d70cc1ec4149c7bf429
parent 6377884c65418b193716b320c274f489ca5a69ef
Author: Brian Swetland <swetland@frotz.net>
Date:   Mon, 14 Jan 2013 00:08:45 -0800

minimal wavefront obj loader

Diffstat:
M
Makefile
 | 
11
++++++++---
A
cube.mtl
 | 
7
+++++++
A
cube.obj
 | 
95
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
loadobj.c
 | 
239
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
A
test3.c
 | 
124
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
util.h
 | 
10
++++++++++

6 files changed, 483 insertions(+), 3 deletions(-)
diff --git a/Makefile b/Makefile
@@ -8,9 +8,9 @@ SDLLIBS := $(shell $(SDLCFG) --libs)
 CFLAGS := $(SDLFLAGS) -DWITH_SDL2=0 -Wall
 LIBS := $(SDLLIBS) -lGL -lm -lpng
 
-COMMONOBJS := util.o sdlglue.o loadpng.o loadfile.o
+COMMONOBJS := util.o sdlglue.o loadpng.o loadfile.o loadobj.o
 
-all: test1 test2
+all: test1 test2 test3
 
 TEST1OBJS := test1.o $(COMMONOBJS)
 
@@ -22,5 +22,10 @@ TEST2OBJS := test2.o $(COMMONOBJS)
 test2: $(TEST2OBJS)
 	$(CC) -o test2 $(TEST2OBJS) $(LIBS)
 
+TEST3OBJS := test3.o $(COMMONOBJS)
+
+test3: $(TEST3OBJS)
+	$(CC) -o test3 $(TEST3OBJS) $(LIBS)
+
 clean::
-	rm -f test1 test2 *.o
+	rm -f test1 test2 test3 *.o
diff --git a/cube.mtl b/cube.mtl
@@ -0,0 +1,7 @@
+newmtl mat0
+Kd 1 1 1
+Ka 0.2 0.2 0.2
+Ks 0.2 0.2 0.2
+Ns 128
+Tr 0
+map_Kd cube-texture.png
diff --git a/cube.obj b/cube.obj
@@ -0,0 +1,95 @@
+mtllib cube.mtl
+g g0
+v -1 1 -1
+v 1 1 -1
+v 1 1 1
+v -1 1 1
+v -1 -1 1
+v 1 -1 1
+v 1 -1 -1
+v -1 -1 -1
+vn 0 -1 0
+vn 0 -1 0
+vn 0 -1 0
+vn 0 -1 0
+vn 0 -1 0
+vn 0 -1 0
+vn 0 1 0
+vn 0 1 0
+vn 0 1 0
+vn 0 1 0
+vn 0 1 0
+vn 0 1 0
+vn 0 0 1
+vn 0 0 1
+vn 0 0 1
+vn 0 0 1
+vn 0 0 1
+vn 0 0 1
+vn 0 0 -1
+vn 0 0 -1
+vn 0 0 -1
+vn 0 0 -1
+vn 0 0 -1
+vn 0 0 -1
+vn -1 0 0
+vn -1 0 0
+vn -1 0 0
+vn -1 0 0
+vn -1 0 0
+vn -1 0 0
+vn 1 0 0
+vn 1 0 0
+vn 1 0 0
+vn 1 0 0
+vn 1 0 0
+vn 1 0 0
+vt 0.25 0.25
+vt 0.5 0.5
+vt 0.25 0.5
+vt 0.5 0.5
+vt 0.25 0.25
+vt 0.5 0.25
+vt 0.5 1
+vt 0.25 0.75
+vt 0.5 0.75
+vt 0.25 0.75
+vt 0.5 1
+vt 0.25 1
+vt 0.25 0.75
+vt 0.5 0.5
+vt 0.5 0.75
+vt 0.5 0.5
+vt 0.25 0.75
+vt 0.25 0.5
+vt 1 0.5
+vt 0.75 0.75
+vt 0.75 0.5
+vt 0.75 0.75
+vt 1 0.5
+vt 1 0.75
+vt 0 0.5
+vt 0.25 0.75
+vt 0 0.75
+vt 0.25 0.75
+vt 0 0.5
+vt 0.25 0.5
+vt 0.5 0.5
+vt 0.75 0.75
+vt 0.5 0.75
+vt 0.75 0.75
+vt 0.5 0.5
+vt 0.75 0.5
+usemtl mat0
+f 8/1/1 6/2/2 5/3/3
+f 6/4/4 8/5/5 7/6/6
+f 2/7/7 4/8/8 3/9/9
+f 4/10/10 2/11/11 1/12/12
+f 4/13/13 6/14/14 3/15/15
+f 6/16/16 4/17/17 5/18/18
+f 8/19/19 2/20/20 7/21/21
+f 2/22/22 8/23/23 1/24/24
+f 8/25/25 4/26/26 1/27/27
+f 4/28/28 8/29/29 5/30/30
+f 6/31/31 2/32/32 3/33/33
+f 2/34/34 6/35/35 7/36/36
diff --git a/loadobj.c b/loadobj.c
@@ -0,0 +1,239 @@
+/* Copyright 2013 Brian Swetland <swetland@frotz.net>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "util.h"
+
+struct v3 {
+	float x;
+	float y;
+	float z;
+};
+
+struct v2 {
+	float u;
+	float v;
+};
+
+struct i3 {
+	unsigned v;
+	unsigned vt;
+	unsigned vn;
+};
+
+struct obj {
+	struct v3 *v;
+	struct v3 *vn;
+	struct v2 *vt;	
+	struct i3 *f;
+	unsigned max_v, num_v;
+	unsigned max_vn, num_vn;
+	unsigned max_vt, num_vt;
+	unsigned max_f, num_f;
+};
+
+static void obj_destroy(struct obj *o) {
+	if (o->v) free(o->v);
+	if (o->vn) free(o->vn);
+	if (o->vt) free(o->vt);
+	if (o->f) free(o->f);
+	free(o);
+}
+
+static void *resize(void *array, unsigned *max, unsigned esz) {
+	void *tmp;
+	unsigned n = *max ? *max * 2 : 32;
+	tmp = realloc(array, esz * n);
+	if (!tmp)
+		free(array);
+	*max = n;
+	return tmp;
+}
+	
+static int obj_add_v(struct obj *o, float x, float y, float z) {
+	unsigned n = o->num_v;
+	if (n == o->max_v)
+		if(!(o->v = resize(o->v, &o->max_v, sizeof(struct v3))))
+			return -1;
+	o->v[n].x = x;
+	o->v[n].y = y;
+	o->v[n].z = z;
+	o->num_v = n + 1;
+	return 0;		
+}
+
+static int obj_add_vn(struct obj *o, float x, float y, float z) {
+	unsigned n = o->num_vn;
+	if (n == o->max_vn)
+		if(!(o->vn = resize(o->vn, &o->max_vn, sizeof(struct v3))))
+			return -1;
+	o->vn[n].x = x;
+	o->vn[n].y = y;
+	o->vn[n].z = z;
+	o->num_vn = n + 1;
+	return 0;		
+}
+
+static int obj_add_vt(struct obj *o, float u, float v) {
+	unsigned n = o->num_vt;
+	if (n == o->max_vt)
+		if(!(o->vt = resize(o->vt, &o->max_vt, sizeof(struct v3))))
+			return -1;
+	o->vt[n].u = u;
+	o->vt[n].v = v;
+	o->num_vt = n + 1;
+	return 0;		
+}
+
+static int obj_add_f(struct obj *o, int v, int vt, int vn) {
+	unsigned n = o->num_f;
+	if (n == o->max_f)
+		if(!(o->f = resize(o->f, &o->max_f, sizeof(struct v3))))
+			return -1;
+
+	/* XXX: range check */
+	v -= 1;
+	vt -= 1;
+	vn -= 1;
+
+	o->f[n].v = v;
+	o->f[n].vt = vt;
+	o->f[n].vn = vn;
+	o->num_f = n + 1;
+	return 0;		
+}
+
+struct obj *load_obj(const char *fn) {
+	char buf[128];
+	FILE *fp;
+	struct obj *o;
+	float x, y, z;
+	int a, b, c;
+
+	if (!(fp = fopen(fn, "r")))
+		goto exit;
+
+	o = malloc(sizeof(struct obj));
+	if (!o)
+		goto close_and_exit;
+	memset(o, 0, sizeof(struct obj));
+
+	while (fgets(buf, sizeof(buf), fp) != 0) {
+		if (!strncmp(buf, "v ", 2)) {
+			sscanf(buf + 2, "%f %f %f", &x, &y, &z);
+			obj_add_v(o, x, y, z);
+		} else if (!strncmp(buf, "vn ", 3)) {
+			sscanf(buf + 3, "%f %f %f", &x, &y, &z);
+			obj_add_vn(o, x, y, z);
+		} else if (!strncmp(buf, "vt ", 3)) {
+			sscanf(buf + 3, "%f %f", &x, &y);
+			obj_add_vt(o, x, y);
+		} else if (!strncmp(buf, "f ", 2)) {
+			char *tmp = buf + 2;
+			/* XXX: handle non-triangles */
+			while (sscanf(tmp, "%d/%d/%d", &a, &b, &c) == 3) {
+				obj_add_f(o, a, b, c);
+				tmp = strstr(tmp, " ");
+				if (!tmp) break;
+				tmp++;
+			}
+		} else {
+//			fprintf(stderr,"ignoring: %s", buf);
+		}
+	}
+
+close_and_exit:
+	fclose(fp);
+exit:
+	return o;	
+}
+
+static struct model *obj_to_model(struct obj *o) {
+	int i, j, n;
+	struct model *m;
+
+	if(!(m = malloc(sizeof(struct model))))
+		return 0;
+	memset(m, 0, sizeof(struct model));
+
+	if (!(m->vdata = malloc(sizeof(float) * 8 * o->num_f))) {
+		free(m);
+		return 0;
+	}
+	if (!(m->idx = malloc(sizeof(short) * o->num_f))) {
+		free(m->vdata);
+		free(m);
+		return 0;
+	}
+
+	for (n = 0, i = 0; i < o->num_f; i++) {
+		float data[8];
+		data[0] = o->v[o->f[i].v].x;
+		data[1] = o->v[o->f[i].v].y;
+		data[2] = o->v[o->f[i].v].z;
+		data[3] = o->vn[o->f[i].vn].x;
+		data[4] = o->vn[o->f[i].vn].y;
+		data[5] = o->vn[o->f[i].vn].z;
+		data[6] = o->vt[o->f[i].vt].u;
+		data[7] = o->vt[o->f[i].vt].v;
+		for (j = 0; j < n; j++)
+			if (!memcmp(data, &m->vdata[8 * j], sizeof(float) * 8))
+				goto found_it;
+		memcpy(&m->vdata[8 * j], data, sizeof(float) * 8);
+		n++;
+found_it:
+		m->idx[i] = j;
+	}
+
+	m->vcount = n;
+	m->icount = o->num_f;
+
+	return m;
+}
+
+#if 0
+void model_dump(struct model *m, FILE *fp) {
+	int i;
+	fprintf(fp, "struct model M = {\n");
+	fprintf(fp, "  .vdata = {\n");
+	for (i = 0; i < m->vcount; i++)
+		fprintf(fp, "    %f, %f, %f,\n    %f, %f, %f, %f, %f,\n",
+			m->vdata[i*8+0], m->vdata[i*8+1],
+			m->vdata[i*8+2], m->vdata[i*8+3], 
+			m->vdata[i*8+4], m->vdata[i*8+5],
+			m->vdata[i*8+6], m->vdata[i*8+7]);
+	fprintf(fp, "  },\n  .idx[] = {\n");
+	for (i = 0; i < m->icount; i += 3) 
+		fprintf(fp, "    %d, %d, %d,\n",
+			m->idx[i+0], m->idx[i+1], m->idx[i+2]);
+	fprintf(fp, "  },\n  .vcount = %d,\n  .icount = %d,\n};\n",
+		m->vcount, m->icount);
+}
+#endif
+
+struct model *load_wavefront_obj(const char *fn) {
+	struct obj *o;
+	struct model *m;
+	o = load_obj(fn);
+	if (!o)
+		return 0;
+	m = obj_to_model(o);
+	obj_destroy(o);
+	return m;
+} 
+
diff --git a/test3.c b/test3.c
@@ -0,0 +1,124 @@
+/* Copyright 2013 Brian Swetland <swetland@frotz.net>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "util.h"
+#include "glue.h"
+
+#include <math.h>
+
+void *texdata;
+unsigned texw, texh;
+
+const char *vert_src, *frag_src;
+
+GLuint pgm, vshd, fshd, tex0;
+GLuint _vPosition, _vUV;
+GLuint _uMVP, _uSampler;
+
+mat4 perspective;
+mat4 MVP;
+
+float a = 0.0;
+
+struct model *m;
+
+int scene_init(struct ctxt *c) {
+	float aspect = ((float) c->width) / ((float) c->height);
+
+	if (!(texdata = load_png_rgba("cube-texture.png", &texw, &texh))) 
+		return -1;
+	if (!(vert_src = load_file("test1.vertex.glsl", 0)))
+		return -1;
+	if (!(frag_src = load_file("test1.fragment.glsl", 0)))
+		return -1;
+
+	if (!(m = load_wavefront_obj("cube.obj")))
+		return -1;
+
+	mtx_identity(MVP);
+	mtx_perspective(perspective, 60.0, aspect, 1.0, 10.0);
+
+	glViewport(0, 0, c->width, c->height);
+	glClearColor(0, 0, 0, 0);
+	glClearDepth(1.0f);
+
+	if (shader_compile(vert_src, frag_src, &pgm, &vshd, &fshd))
+		return -1;
+
+	_vPosition = glGetAttribLocation(pgm, "vPosition");
+	_vUV = glGetAttribLocation(pgm, "vUV");
+	_uMVP = glGetUniformLocation(pgm, "uMVP");
+	_uSampler = glGetUniformLocation(pgm, "uSampler");
+
+	if(glGetError() != GL_NO_ERROR) fprintf(stderr,"OOPS!\n");
+
+	glEnable(GL_TEXTURE_2D);
+	glEnable(GL_DEPTH_TEST);
+	glEnable(GL_CULL_FACE);
+	glFrontFace(GL_CCW);
+//	glEnable(GL_BLEND);
+//	glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
+
+	glGenTextures(1, &tex0);
+	
+	glBindTexture(GL_TEXTURE_2D, tex0);
+	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, texw, texh, 0, GL_RGBA,
+		GL_UNSIGNED_BYTE, texdata);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+
+	return 0;
+}
+
+#include "data.h"
+
+int scene_draw(struct ctxt *c) {
+	mat4 camera;
+
+	mtx_identity(camera);
+	mtx_translate(camera, 0, 0, -5.0);
+	mtx_rotate_y(camera, a);
+	mtx_rotate_x(camera, 25.0);
+
+	mtx_mul_unsafe(MVP, camera, perspective);
+
+	a += 1.0;
+	if (a > 360.0) a = 0.0;
+
+	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+	glUseProgram(pgm);
+
+	glActiveTexture(GL_TEXTURE0);
+	glBindTexture(GL_TEXTURE_2D, tex0);
+
+	glUniformMatrix4fv(_uMVP, 1, GL_FALSE, (void*) MVP);
+	glUniform1i(_uSampler, 0);
+
+	glVertexAttribPointer(_vPosition, 3, GL_FLOAT, GL_FALSE, 8*4, m->vdata);
+	glEnableVertexAttribArray(_vPosition);
+
+	glVertexAttribPointer(_vUV, 2, GL_FLOAT, GL_FALSE, 8*4, m->vdata + 6);
+	glEnableVertexAttribArray(_vUV);
+
+	glDrawElements(GL_TRIANGLES, m->icount, GL_UNSIGNED_SHORT, m->idx);
+
+	return 0;
+}
+
diff --git a/util.h b/util.h
@@ -52,5 +52,15 @@ void mtx_perspective(mat4 out,
 void *load_png_rgba(const char *fn, unsigned *width, unsigned *height);
 void *load_file(const char *fn, unsigned *sz);
 
+/* model helpers */
+
+struct model {
+	float *vdata; /* { vertex[3], normal[3], texcoord[2] } * vcount */
+	unsigned short *idx;
+	unsigned vcount;
+	unsigned icount;
+};
+
+struct model *load_wavefront_obj(const char *fn);
 #endif