progs/objviewer: Wavefront .obj file loader/viewer demo

Adapted from code written by Nate Robins.  See README.txt.

1 files changed, 480 insertions, 0 deletions

diff --git a/progs/objviewer/glmdraw.c b/progs/objviewer/glmdraw.c
new file mode 100644
index 00000000000..cc986d9d1e3
--- /dev/null
+++ b/progs/objviewer/glmdraw.c
@@ -0,0 +1,480 @@
+/* */
+
+#define GL_GLEXT_PROTOTYPES
+
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <GL/gl.h>
+#include <GL/glu.h>
+#include "glm.h"
+#include "readtex.h"
+#include "shaderutil.h"
+
+
+/* defines */
+#define T(x) model->triangles[(x)]
+
+
+/* glmDraw: Renders the model to the current OpenGL context using the
+ * mode specified.
+ *
+ * model    - initialized GLMmodel structure
+ * mode     - a bitwise OR of values describing what is to be rendered.
+ *            GLM_NONE     -  render with only vertices
+ *            GLM_FLAT     -  render with facet normals
+ *            GLM_SMOOTH   -  render with vertex normals
+ *            GLM_TEXTURE  -  render with texture coords
+ *            GLM_COLOR    -  render with colors (color material)
+ *            GLM_MATERIAL -  render with materials
+ *            GLM_COLOR and GLM_MATERIAL should not both be specified.  
+ *            GLM_FLAT and GLM_SMOOTH should not both be specified.  
+ */
+GLvoid
+glmDraw(GLMmodel* model, GLuint mode)
+{
+  GLuint i;
+  GLMgroup* group;
+
+  assert(model);
+  assert(model->vertices);
+
+  /* do a bit of warning */
+  if (mode & GLM_FLAT && !model->facetnorms) {
+    printf("glmDraw() warning: flat render mode requested "
+	   "with no facet normals defined.\n");
+    mode &= ~GLM_FLAT;
+  }
+  if (mode & GLM_SMOOTH && !model->normals) {
+    printf("glmDraw() warning: smooth render mode requested "
+	   "with no normals defined.\n");
+    mode &= ~GLM_SMOOTH;
+  }
+  if (mode & GLM_TEXTURE && !model->texcoords) {
+    printf("glmDraw() warning: texture render mode requested "
+	   "with no texture coordinates defined.\n");
+    mode &= ~GLM_TEXTURE;
+  }
+  if (mode & GLM_FLAT && mode & GLM_SMOOTH) {
+    printf("glmDraw() warning: flat render mode requested "
+	   "and smooth render mode requested (using smooth).\n");
+    mode &= ~GLM_FLAT;
+  }
+  if (mode & GLM_COLOR && !model->materials) {
+    printf("glmDraw() warning: color render mode requested "
+	   "with no materials defined.\n");
+    mode &= ~GLM_COLOR;
+  }
+  if (mode & GLM_MATERIAL && !model->materials) {
+    printf("glmDraw() warning: material render mode requested "
+	   "with no materials defined.\n");
+    mode &= ~GLM_MATERIAL;
+  }
+  if (mode & GLM_COLOR && mode & GLM_MATERIAL) {
+    printf("glmDraw() warning: color and material render mode requested "
+	   "using only material mode\n");
+    mode &= ~GLM_COLOR;
+  }
+  if (mode & GLM_COLOR)
+    glEnable(GL_COLOR_MATERIAL);
+  if (mode & GLM_MATERIAL)
+    glDisable(GL_COLOR_MATERIAL);
+
+  glPushMatrix();
+  glTranslatef(model->position[0], model->position[1], model->position[2]);
+
+  glBegin(GL_TRIANGLES);
+  group = model->groups;
+  while (group) {
+    if (mode & GLM_MATERIAL) {
+      glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, 
+		   model->materials[group->material].ambient);
+      glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, 
+		   model->materials[group->material].diffuse);
+      glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, 
+		   model->materials[group->material].specular);
+       glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 
+  		  model->materials[group->material].shininess);
+    }
+
+    if (mode & GLM_COLOR) {
+      glColor3fv(model->materials[group->material].diffuse);
+    }
+
+    for (i = 0; i < group->numtriangles; i++) {
+      if (mode & GLM_FLAT)
+	glNormal3fv(&model->facetnorms[3 * T(group->triangles[i]).findex]);
+      
+      if (mode & GLM_SMOOTH)
+	glNormal3fv(&model->normals[3 * T(group->triangles[i]).nindices[0]]);
+      if (mode & GLM_TEXTURE)
+	glTexCoord2fv(&model->texcoords[2*T(group->triangles[i]).tindices[0]]);
+      glVertex3fv(&model->vertices[3 * T(group->triangles[i]).vindices[0]]);
+#if 0
+      printf("%f %f %f\n", 
+	     model->vertices[3 * T(group->triangles[i]).vindices[0] + X],
+	     model->vertices[3 * T(group->triangles[i]).vindices[0] + Y],
+	     model->vertices[3 * T(group->triangles[i]).vindices[0] + Z]);
+#endif
+      
+      if (mode & GLM_SMOOTH)
+	glNormal3fv(&model->normals[3 * T(group->triangles[i]).nindices[1]]);
+      if (mode & GLM_TEXTURE)
+	glTexCoord2fv(&model->texcoords[2*T(group->triangles[i]).tindices[1]]);
+      glVertex3fv(&model->vertices[3 * T(group->triangles[i]).vindices[1]]);
+#if 0
+      printf("%f %f %f\n", 
+	     model->vertices[3 * T(group->triangles[i]).vindices[1] + X],
+	     model->vertices[3 * T(group->triangles[i]).vindices[1] + Y],
+	     model->vertices[3 * T(group->triangles[i]).vindices[1] + Z]);
+#endif
+      
+      if (mode & GLM_SMOOTH)
+	glNormal3fv(&model->normals[3 * T(group->triangles[i]).nindices[2]]);
+      if (mode & GLM_TEXTURE)
+	glTexCoord2fv(&model->texcoords[2*T(group->triangles[i]).tindices[2]]);
+      glVertex3fv(&model->vertices[3 * T(group->triangles[i]).vindices[2]]);
+#if 0
+      printf("%f %f %f\n", 
+	     model->vertices[3 * T(group->triangles[i]).vindices[2] + X],
+	     model->vertices[3 * T(group->triangles[i]).vindices[2] + Y],
+	     model->vertices[3 * T(group->triangles[i]).vindices[2] + Z]);
+#endif
+      
+    }
+    
+    group = group->next;
+  }
+  glEnd();
+
+  glPopMatrix();
+}
+
+
+void
+glmMakeVBOs(GLMmodel *model)
+{
+   uint bytes, vertexFloats, i;
+   float *buffer;
+
+   vertexFloats = 3;
+   model->posOffset = 0;
+
+   if (model->numnormals > 0) {
+      assert(model->numnormals == model->numvertices);
+      model->normOffset = vertexFloats * sizeof(GLfloat);
+      vertexFloats += 3;
+   }      
+
+   if (model->numtexcoords > 0) {
+      assert(model->numtexcoords == model->numvertices);
+      model->texOffset = vertexFloats * sizeof(GLfloat);
+      vertexFloats += 2;
+   }
+
+   model->vertexSize = vertexFloats;
+
+   bytes = (model->numvertices + 1) * vertexFloats * sizeof(float);
+
+   buffer = (float *) malloc(bytes);
+   for (i = 0; i < model->numvertices; i++) {
+      /* copy vertex pos */
+      uint j = 0;
+      buffer[i * vertexFloats + j++] = model->vertices[i * 3 + 0];
+      buffer[i * vertexFloats + j++] = model->vertices[i * 3 + 1];
+      buffer[i * vertexFloats + j++] = model->vertices[i * 3 + 2];
+      if (model->numnormals > 0) {
+         buffer[i * vertexFloats + j++] = model->normals[i * 3 + 0];
+         buffer[i * vertexFloats + j++] = model->normals[i * 3 + 1];
+         buffer[i * vertexFloats + j++] = model->normals[i * 3 + 2];
+      }
+      if (model->numtexcoords > 0) {
+         buffer[i * vertexFloats + j++] = model->texcoords[i * 2 + 0];
+         buffer[i * vertexFloats + j++] = model->texcoords[i * 2 + 1];
+      }
+   }
+
+   glGenBuffersARB(1, &model->vbo);
+   glBindBufferARB(GL_ARRAY_BUFFER_ARB, model->vbo);
+   glBufferDataARB(GL_ARRAY_BUFFER_ARB, bytes, buffer, GL_STATIC_DRAW_ARB);
+   glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
+
+   free(buffer);
+}
+
+
+static void
+_glmLoadTexture(GLMmaterial *mat)
+{
+  if (mat->map_kd) {
+     GLint imgWidth, imgHeight;
+     GLenum imgFormat;
+     GLubyte *image = NULL;
+     
+     glGenTextures(1, &mat->texture_kd);
+
+     image = LoadRGBImage( mat->map_kd, &imgWidth, &imgHeight, &imgFormat );
+     if (!image) {
+        /*fprintf(stderr, "Couldn't open texture %s\n", mat->map_kd);*/
+        free(mat->map_kd);
+        mat->map_kd = NULL;
+        mat->texture_kd = 0;
+        return;
+     }
+     if (0)
+        printf("load texture %s %d x %d\n", mat->map_kd, imgWidth, imgHeight);
+
+     glBindTexture(GL_TEXTURE_2D, mat->texture_kd);
+     gluBuild2DMipmaps(GL_TEXTURE_2D, 3, imgWidth, imgHeight,
+                       imgFormat, GL_UNSIGNED_BYTE, image);
+     free(image);
+
+     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
+     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
+     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR );
+     glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR );
+  }
+}
+
+void
+glmLoadTextures(GLMmodel *model)
+{
+   uint i;
+
+   for (i = 0; i < model->nummaterials; i++) {
+      GLMmaterial *mat = &model->materials[i];
+      _glmLoadTexture(mat);
+   }
+}
+
+
+void
+glmDrawVBO(GLMmodel *model)
+{
+   GLMgroup* group;
+   int mode = GLM_MATERIAL;
+
+   assert(model->vbo);
+
+   glBindBufferARB(GL_ARRAY_BUFFER_ARB, model->vbo);
+
+   glVertexPointer(3, GL_FLOAT, model->vertexSize * sizeof(float),
+                   (void *) model->posOffset);
+   glEnableClientState(GL_VERTEX_ARRAY);
+
+   if (model->numnormals > 0) {
+      glNormalPointer(GL_FLOAT, model->vertexSize * sizeof(float),
+                      (void *) model->normOffset);
+      glEnableClientState(GL_NORMAL_ARRAY);
+   }
+
+   if (model->numtexcoords > 0) {
+      glTexCoordPointer(2, GL_FLOAT, model->vertexSize * sizeof(float),
+                        (void *) model->texOffset);
+      glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+   }
+
+   glPushMatrix();
+   glTranslatef(model->position[0], model->position[1], model->position[2]);
+   glScalef(model->scale, model->scale, model->scale);
+
+   for (group = model->groups; group; group = group->next) {
+      if (0&&strcmp(group->name, "Fuselage") != 0)
+         continue;
+
+      if (group->numtriangles > 0) {
+
+         if (model->materials && (mode & GLM_MATERIAL)) {
+#if 0
+            glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, 
+                         model->materials[group->material].ambient);
+            glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, 
+                         model->materials[group->material].diffuse);
+            glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, 
+                         model->materials[group->material].specular);
+            glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 
+                        model->materials[group->material].shininess);
+#else
+            glmShaderMaterial(&model->materials[group->material]);
+#endif
+         }
+
+
+#if 0
+         glDrawElements(GL_TRIANGLES, 3 * group->numtriangles,
+                        GL_UNSIGNED_INT, group->triIndexes);
+#else
+         glDrawRangeElements(GL_TRIANGLES,
+                             group->minIndex, group->maxIndex,
+                             3 * group->numtriangles,
+                             GL_UNSIGNED_INT, group->triIndexes);
+#endif
+
+         glDisable(GL_BLEND);
+      }
+   }
+
+   glPopMatrix();
+
+   glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
+   glDisableClientState(GL_VERTEX_ARRAY);
+   glDisableClientState(GL_NORMAL_ARRAY);
+   glDisableClientState(GL_TEXTURE_COORD_ARRAY);
+}
+
+
+
+/* glmList: Generates and returns a display list for the model using
+ * the mode specified.
+ *
+ * model    - initialized GLMmodel structure
+ * mode     - a bitwise OR of values describing what is to be rendered.
+ *            GLM_NONE     -  render with only vertices
+ *            GLM_FLAT     -  render with facet normals
+ *            GLM_SMOOTH   -  render with vertex normals
+ *            GLM_TEXTURE  -  render with texture coords
+ *            GLM_COLOR    -  render with colors (color material)
+ *            GLM_MATERIAL -  render with materials
+ *            GLM_COLOR and GLM_MATERIAL should not both be specified.  
+ *            GLM_FLAT and GLM_SMOOTH should not both be specified.  
+ */
+GLuint
+glmList(GLMmodel* model, GLuint mode)
+{
+  GLuint list;
+
+  list = glGenLists(1);
+  glNewList(list, GL_COMPILE);
+  glmDraw(model, mode);
+  glEndList();
+
+  return list;
+}
+
+
+
+static const char *VertexShader =
+   "varying vec3 normal; \n"
+   "void main() { \n"
+   "   gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; \n"
+   "   normal = gl_NormalMatrix * gl_Normal; \n"
+   "   gl_TexCoord[0] = gl_MultiTexCoord0; \n"
+   "} \n";
+
+/**
+ * Two %s substitutions:
+ *   diffuse texture? true/false
+ *   specular texture? true/false
+ */
+static const char *TexFragmentShader =
+   "uniform vec4 ambient, diffuse, specular; \n"
+   "uniform vec4 ambientLight, diffuseLight, specularLight; \n"
+   "uniform float shininess; \n"
+   "uniform sampler2D diffTex; \n"
+   "uniform samplerCube specTex; \n"
+   "varying vec3 normal; \n"
+   "\n"
+   "void main() \n"
+   "{ \n"
+   "   vec4 diffTerm, specTerm; \n"
+   "   float dotProd = max(dot(gl_LightSource[0].position.xyz, \n"
+   "                           normalize(normal)), 0.0);\n"
+   "   float dotProd2 = max(dot(-gl_LightSource[0].position.xyz, \n"
+   "                           normalize(normal)), 0.0);\n"
+   "   dotProd += dotProd2; \n"
+   " \n"
+   "   diffTerm = diffuse * diffuseLight * dotProd; \n"
+   "   if (%s) \n"
+   "      diffTerm *= texture2D(diffTex, gl_TexCoord[0].st); \n"
+   " \n"
+   "   specTerm = specular * specularLight * pow(dotProd, shininess); \n"
+   "   if (%s) \n"
+   "      specTerm *= textureCube(specTex, normal); \n"
+   " \n"
+   "   gl_FragColor = ambient * ambientLight + diffTerm + specTerm; \n"
+   "} \n";
+
+
+void
+glmShaderMaterial(GLMmaterial *mat)
+{
+   static const float ambientLight[4] = { 0.1, 0.1, 0.1, 0.0 };
+   static const float diffuseLight[4] = { 0.75, 0.75, 0.75, 1.0 };
+   static const float specularLight[4] = { 1.0, 1.0, 1.0, 0.0 };
+
+   if (!mat->prog) {
+      /* make shader now */
+      char newShader[10000];
+      GLuint vs, fs;
+      const char *diffuseTex = mat->texture_kd ? "true" : "false";
+      const char *specularTex = mat->texture_ks ? "true" : "false";
+      GLint uAmbientLight, uDiffuseLight, uSpecularLight;
+
+      /* replace %d with 0 or 1 */
+      sprintf(newShader, TexFragmentShader, diffuseTex, specularTex);
+      if (0)
+         printf("===== new shader =====\n%s\n============\n", newShader);
+
+      vs = CompileShaderText(GL_VERTEX_SHADER, VertexShader);
+      fs = CompileShaderText(GL_FRAGMENT_SHADER, newShader);
+      mat->prog = LinkShaders(vs, fs);
+      assert(mat->prog);
+
+      glUseProgram(mat->prog);
+
+      mat->uAmbient = glGetUniformLocation(mat->prog, "ambient");
+      mat->uDiffuse = glGetUniformLocation(mat->prog, "diffuse");
+      mat->uSpecular = glGetUniformLocation(mat->prog, "specular");
+      mat->uShininess = glGetUniformLocation(mat->prog, "shininess");
+      mat->uDiffTex = glGetUniformLocation(mat->prog, "diffTex");
+      mat->uSpecTex = glGetUniformLocation(mat->prog, "specTex");
+
+      uAmbientLight = glGetUniformLocation(mat->prog, "ambientLight");
+      uDiffuseLight = glGetUniformLocation(mat->prog, "diffuseLight");
+      uSpecularLight = glGetUniformLocation(mat->prog, "specularLight");
+
+      glUniform4fv(mat->uAmbient, 1, mat->ambient);
+      glUniform4fv(mat->uDiffuse, 1, mat->diffuse);
+      glUniform4fv(mat->uSpecular, 1, mat->specular);
+      glUniform1f(mat->uShininess, mat->shininess);
+      glUniform1i(mat->uDiffTex, 0);
+      glUniform1i(mat->uSpecTex, 1);
+
+      glUniform4fv(uAmbientLight, 1, ambientLight);
+      glUniform4fv(uDiffuseLight, 1, diffuseLight);
+      glUniform4fv(uSpecularLight, 1, specularLight);
+   }
+
+   glActiveTexture(GL_TEXTURE1);
+   if (mat->texture_ks)
+      glBindTexture(GL_TEXTURE_CUBE_MAP, mat->texture_ks);
+   else
+      glBindTexture(GL_TEXTURE_CUBE_MAP, 0);
+
+   glActiveTexture(GL_TEXTURE0);
+   if (mat->texture_kd)
+      glBindTexture(GL_TEXTURE_2D, mat->texture_kd);
+   else
+      glBindTexture(GL_TEXTURE_2D, 0);
+
+   if (mat->diffuse[3] < 1.0) {
+      glEnable(GL_BLEND);
+      glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+   }
+   else {
+      glDisable(GL_BLEND);
+   }
+
+   glUseProgram(mat->prog);
+}
+
+
+void
+glmSpecularTexture(GLMmodel *model, uint cubeTex)
+{
+   uint i;
+
+   for (i = 0; i < model->nummaterials; i++) {
+      model->materials[i].texture_ks = cubeTex;
+   }
+}