progs/glsl/shtest.c

/*
 * Simple shader test harness.
 * Brian Paul
 * 13 Aug 2009
 *
 * Usage:
 *   shtest --vs vertShaderFile --fs fragShaderFile
 *
 *   In this case the given vertex/frag shaders are read and compiled.
 *   Random values are assigned to the uniforms.
 *
 * or:
 *   shtest configFile
 *
 *   In this case a config file is read that specifies the file names
 *   of the shaders plus initial values for uniforms.
 *
 * Example config file:
 *
 * vs shader.vert
 * fs shader.frag
 * uniform pi 3.14159
 * uniform v1 1.0 0.5 0.2 0.3
 *
 */


#include <assert.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <GL/glew.h>
#include <GL/glu.h>
#include <GL/glut.h>
#include "shaderutil.h"


typedef enum
{
   SPHERE,
   CUBE,
   NUM_SHAPES
} shape;


static char *FragShaderFile = NULL;
static char *VertShaderFile = NULL;
static char *ConfigFile = NULL;

/* program/shader objects */
static GLuint fragShader;
static GLuint vertShader;
static GLuint Program;


#define MAX_UNIFORMS 100
static struct uniform_info Uniforms[MAX_UNIFORMS];
static GLuint NumUniforms = 0;


#define MAX_ATTRIBS 100
static struct attrib_info Attribs[MAX_ATTRIBS];
static GLuint NumAttribs = 0;


/**
 * Config file info.
 */
struct config_file
{
   struct name_value
   {
      char name[100];
      float value[4];
      int type;
   } uniforms[100];

   int num_uniforms;
};


static GLint win = 0;
static GLboolean Anim = GL_FALSE;
static GLfloat TexRot = 0.0;
static GLfloat xRot = 0.0f, yRot = 0.0f, zRot = 0.0f;
static shape Object = SPHERE;


static float
RandomFloat(float min, float max)
{
   int k = rand() % 10000;
   float x = min + (max - min) * k / 10000.0;
   return x;
}


/** Set new random values for uniforms */
static void
RandomUniformValues(void)
{
   GLuint i;
   for (i = 0; i < NumUniforms; i++) {
      if (Uniforms[i].type == GL_FLOAT) {
         Uniforms[i].value[0] = RandomFloat(0.0, 1.0);
      }
      else {
         Uniforms[i].value[0] = RandomFloat(-1.0, 2.0);
         Uniforms[i].value[1] = RandomFloat(-1.0, 2.0);
         Uniforms[i].value[2] = RandomFloat(-1.0, 2.0);
         Uniforms[i].value[3] = RandomFloat(-1.0, 2.0);
      }
   }
}


static void
Idle(void)
{
   yRot += 2.0;
   if (yRot > 360.0)
      yRot -= 360.0;
   glutPostRedisplay();
}



static void
SquareVertex(GLfloat s, GLfloat t, GLfloat size)
{
   GLfloat x = -size + s * 2.0 * size;
   GLfloat y = -size + t * 2.0 * size;
   glTexCoord2f(s, t);
   glVertex2f(x, y);
}


/*
 * Draw a square, specifying normal and tangent vectors.
 */
static void
Square(GLfloat size)
{
   GLint tangentAttrib = 1;
   glNormal3f(0, 0, 1);
   glVertexAttrib3f(tangentAttrib, 1, 0, 0);
   glBegin(GL_POLYGON);
#if 0
   SquareVertex(0, 0, size);
   SquareVertex(1, 0, size);
   SquareVertex(1, 1, size);
   SquareVertex(0, 1, size);
#else
   glTexCoord2f(0, 0);  glVertex2f(-size, -size);
   glTexCoord2f(1, 0);  glVertex2f( size, -size);
   glTexCoord2f(1, 1);  glVertex2f( size,  size);
   glTexCoord2f(0, 1);  glVertex2f(-size,  size);
#endif
   glEnd();
}


static void
Cube(GLfloat size)
{
   /* +X */
   glPushMatrix();
   glRotatef(90, 0, 1, 0);
   glTranslatef(0, 0, size);
   Square(size);
   glPopMatrix();

   /* -X */
   glPushMatrix();
   glRotatef(-90, 0, 1, 0);
   glTranslatef(0, 0, size);
   Square(size);
   glPopMatrix();

   /* +Y */
   glPushMatrix();
   glRotatef(90, 1, 0, 0);
   glTranslatef(0, 0, size);
   Square(size);
   glPopMatrix();

   /* -Y */
   glPushMatrix();
   glRotatef(-90, 1, 0, 0);
   glTranslatef(0, 0, size);
   Square(size);
   glPopMatrix();


   /* +Z */
   glPushMatrix();
   glTranslatef(0, 0, size);
   Square(size);
   glPopMatrix();

   /* -Z */
   glPushMatrix();
   glRotatef(180, 0, 1, 0);
   glTranslatef(0, 0, size);
   Square(size);
   glPopMatrix();
}


static void
Sphere(GLfloat radius, GLint slices, GLint stacks)
{
   static GLUquadricObj *q = NULL;

   if (!q) {
      q = gluNewQuadric();
      gluQuadricDrawStyle(q, GLU_FILL);
      gluQuadricNormals(q, GLU_SMOOTH);
      gluQuadricTexture(q, GL_TRUE);
   }

   gluSphere(q, radius, slices, stacks);
}


static void
Redisplay(void)
{
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
   
   glPushMatrix();
   glRotatef(xRot, 1.0f, 0.0f, 0.0f);
   glRotatef(yRot, 0.0f, 1.0f, 0.0f);
   glRotatef(zRot, 0.0f, 0.0f, 1.0f);

   glMatrixMode(GL_TEXTURE);
   glLoadIdentity();
   glRotatef(TexRot, 0.0f, 1.0f, 0.0f);
   glMatrixMode(GL_MODELVIEW);

   if (Object == SPHERE) {
      Sphere(2.0, 20, 10);
   }
   else if (Object == CUBE) {
      Cube(2.0);
   }

   glPopMatrix();

   glutSwapBuffers();
}


static void
Reshape(int width, int height)
{
   glViewport(0, 0, width, height);
   glMatrixMode(GL_PROJECTION);
   glLoadIdentity();
   glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
   glMatrixMode(GL_MODELVIEW);
   glLoadIdentity();
   glTranslatef(0.0f, 0.0f, -15.0f);
}


static void
CleanUp(void)
{
   glDeleteShader(fragShader);
   glDeleteShader(vertShader);
   glDeleteProgram(Program);
   glutDestroyWindow(win);
}


static void
Key(unsigned char key, int x, int y)
{
   const GLfloat step = 2.0;
  (void) x;
  (void) y;

   switch(key) {
   case 'a':
      Anim = !Anim;
      if (Anim)
         glutIdleFunc(Idle);
      else
         glutIdleFunc(NULL);
      break;
   case 'z':
      zRot += step;
      break;
   case 'Z':
      zRot -= step;
      break;
   case 'o':
      Object = (Object + 1) % NUM_SHAPES;
      break;
   case 'r':
      RandomUniformValues();
      SetUniformValues(Program, Uniforms);
      PrintUniforms(Uniforms);
      break;
   case 27:
      CleanUp();
      exit(0);
      break;
   }
   glutPostRedisplay();
}


static void
SpecialKey(int key, int x, int y)
{
   const GLfloat step = 2.0;

  (void) x;
  (void) y;

   switch(key) {
   case GLUT_KEY_UP:
      xRot += step;
      break;
   case GLUT_KEY_DOWN:
      xRot -= step;
      break;
   case GLUT_KEY_LEFT:
      yRot -= step;
      break;
   case GLUT_KEY_RIGHT:
      yRot += step;
      break;
   }
   glutPostRedisplay();
}


static void
InitUniforms(const struct config_file *conf,
             struct uniform_info uniforms[])
{
   int i;

   for (i = 0; i < conf->num_uniforms; i++) {
      int j;
      for (j = 0; uniforms[j].name; j++) {
         if (strcmp(uniforms[j].name, conf->uniforms[i].name) == 0) {
            uniforms[j].type = conf->uniforms[i].type;
            uniforms[j].value[0] = conf->uniforms[i].value[0];
            uniforms[j].value[1] = conf->uniforms[i].value[1];
            uniforms[j].value[2] = conf->uniforms[i].value[2];
            uniforms[j].value[3] = conf->uniforms[i].value[3];
         }
      }
   }
}


/**
 * Read a config file.
 */
static void
ReadConfigFile(const char *filename, struct config_file *conf)
{
   char line[1000];
   FILE *f;

   f = fopen(filename, "r");
   if (!f) {
      fprintf(stderr, "Unable to open config file %s\n", filename);
      exit(1);
   }

   conf->num_uniforms = 0;

   /* ugly but functional parser */
   while (!feof(f)) {
      fgets(line, sizeof(line), f);
      if (line[0]) {
         if (strncmp(line, "vs ", 3) == 0) {
            VertShaderFile = strdup(line + 3);
            VertShaderFile[strlen(VertShaderFile) - 1] = 0;
         }
         else if (strncmp(line, "fs ", 3) == 0) {
            FragShaderFile = strdup(line + 3);
            FragShaderFile[strlen(FragShaderFile) - 1] = 0;
         }
         else if (strncmp(line, "uniform ", 8) == 0) {
            char name[1000];
            int k;
            float v1, v2, v3, v4;
            GLenum type;

            k = sscanf(line + 8, "%s %f %f %f %f", name, &v1, &v2, &v3, &v4);

            switch (k) {
            case 1:
               type = GL_NONE;
               abort();
               break;
            case 2:
               type = GL_FLOAT;
               break;
            case 3:
               type = GL_FLOAT_VEC2;
               break;
            case 4:
               type = GL_FLOAT_VEC3;
               break;
            case 5:
               type = GL_FLOAT_VEC4;
               break;
            }

            strcpy(conf->uniforms[conf->num_uniforms].name, name);
            conf->uniforms[conf->num_uniforms].value[0] = v1;
            conf->uniforms[conf->num_uniforms].value[1] = v2;
            conf->uniforms[conf->num_uniforms].value[2] = v3;
            conf->uniforms[conf->num_uniforms].value[3] = v4;
            conf->uniforms[conf->num_uniforms].type = type;
            conf->num_uniforms++;
         }
         else {
            if (strlen(line) > 1) {
               fprintf(stderr, "syntax error in: %s\n", line);
               break;
            }
         }
      }
   }

   fclose(f);
}


static void
Init(void)
{
   struct config_file config;
   memset(&config, 0, sizeof(config));

   if (ConfigFile)
      ReadConfigFile(ConfigFile, &config);

   if (!VertShaderFile) {
      fprintf(stderr, "Error: no vertex shader\n");
      exit(1);
   }

   if (!FragShaderFile) {
      fprintf(stderr, "Error: no fragment shader\n");
      exit(1);
   }

   if (!ShadersSupported())
      exit(1);

   vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertShaderFile);
   fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragShaderFile);
   Program = LinkShaders(vertShader, fragShader);

   glUseProgram(Program);

   NumUniforms = GetUniforms(Program, Uniforms);
   if (config.num_uniforms) {
      InitUniforms(&config, Uniforms);
   }
   else {
      RandomUniformValues();
   }
   SetUniformValues(Program, Uniforms);
   PrintUniforms(Uniforms);

   NumAttribs = GetAttribs(Program, Attribs);
   PrintAttribs(Attribs);

   //assert(glGetError() == 0);

   glClearColor(0.4f, 0.4f, 0.8f, 0.0f);

   glEnable(GL_DEPTH_TEST);

   glColor3f(1, 0, 0);
}


static void
Keys(void)
{
   printf("Keyboard:\n");
   printf("       a  Animation toggle\n");
   printf("       r  Randomize uniform values\n");
   printf("       o  Change object\n");
   printf("  arrows  Rotate object\n");
   printf("     ESC  Exit\n");
}


static void
Usage(void)
{
   printf("Usage:\n");
   printf("   shtest config.shtest\n");
   printf("       Run w/ given config file.\n");
   printf("   shtest --vs vertShader --fs fragShader\n");
   printf("       Load/compile given shaders.\n");
}


static void
ParseOptions(int argc, char *argv[])
{
   int i;

   if (argc == 1) {
      Usage();
      exit(1);
   }

   for (i = 1; i < argc; i++) {
      if (strcmp(argv[i], "--fs") == 0) {
         FragShaderFile = argv[i+1];
         i++;
      }
      else if (strcmp(argv[i], "--vs") == 0) {
         VertShaderFile = argv[i+1];
         i++;
      }
      else {
         /* assume the arg is a config file */
         ConfigFile = argv[i];
         break;
      }
   }
}


int
main(int argc, char *argv[])
{
   glutInit(&argc, argv);
   glutInitWindowPosition( 0, 0);
   glutInitWindowSize(400, 400);
   glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
   win = glutCreateWindow(argv[0]);
   glewInit();
   glutReshapeFunc(Reshape);
   glutKeyboardFunc(Key);
   glutSpecialFunc(SpecialKey);
   glutDisplayFunc(Redisplay);
   ParseOptions(argc, argv);
   Init();
   Keys();
   glutMainLoop();
   return 0;
}