shading language texture demo/test

5 files changed, 637 insertions, 0 deletions

diff --git a/progs/glsl/cubemap.frag.txt b/progs/glsl/cubemap.frag.txt
new file mode 100644
index 0000000000..9c27648aaf
--- /dev/null
+++ b/progs/glsl/cubemap.frag.txt
@@ -0,0 +1,18 @@
+// Fragment shader for cube-texture reflection mapping
+// Brian Paul
+
+
+uniform samplerCube cubeTex;
+varying vec3 normal;
+uniform vec3 lightPos;
+
+void main()
+{
+   // simple diffuse, specular lighting:
+   vec3 lp = normalize(lightPos);
+   float dp = dot(lp, normalize(normal));
+   float spec = pow(dp, 5.0);
+
+   // final color:
+   gl_FragColor = dp * textureCube(cubeTex, gl_TexCoord[0].xyz, 0.0) + spec;
+}
diff --git a/progs/glsl/reflect.vert.txt b/progs/glsl/reflect.vert.txt
new file mode 100644
index 0000000000..402be38bf7
--- /dev/null
+++ b/progs/glsl/reflect.vert.txt
@@ -0,0 +1,19 @@
+// Vertex shader for cube-texture reflection mapping
+// Brian Paul
+
+
+varying vec3 normal;
+
+void main() 
+{
+   vec3 n = gl_NormalMatrix * gl_Normal;
+   vec3 u = normalize(vec3(gl_ModelViewMatrix * gl_Vertex));
+   float two_n_dot_u = 2.0 * dot(n, u);
+   vec4 f;
+   f.xyz = u - n * two_n_dot_u;
+
+   // outputs
+   normal = n;
+   gl_TexCoord[0] = gl_TextureMatrix[0] * f;
+   gl_Position = ftransform();
+}
diff --git a/progs/glsl/shadowtex.frag.txt b/progs/glsl/shadowtex.frag.txt
new file mode 100644
index 0000000000..a6a80da47f
--- /dev/null
+++ b/progs/glsl/shadowtex.frag.txt
@@ -0,0 +1,21 @@
+// Fragment shader for 2D texture with shadow attenuation
+// Brian Paul
+
+
+uniform sampler2D tex2d;
+uniform vec3 lightPos;
+
+void main()
+{
+   // XXX should compute this from lightPos
+   vec2 shadowCenter = vec2(-0.25, -0.25);
+
+   // d = distance from center
+   float d = distance(gl_TexCoord[0].xy, shadowCenter);
+
+   // attenuate and clamp
+   d = clamp(d * d * d, 0.0, 2.0);
+
+   // modulate texture by d for shadow effect
+   gl_FragColor = d * texture2D(tex2d, gl_TexCoord[0].xy, 0.0);
+}
diff --git a/progs/glsl/simple.vert.txt b/progs/glsl/simple.vert.txt
new file mode 100644
index 0000000000..a0abe0dc0b
--- /dev/null
+++ b/progs/glsl/simple.vert.txt
@@ -0,0 +1,9 @@
+// Simple vertex shader
+// Brian Paul
+
+
+void main() 
+{
+   gl_TexCoord[0] = gl_MultiTexCoord0;
+   gl_Position = ftransform();
+}
diff --git a/progs/glsl/texdemo1.c b/progs/glsl/texdemo1.c
new file mode 100644
index 0000000000..d29ecf452b
--- /dev/null
+++ b/progs/glsl/texdemo1.c
@@ -0,0 +1,570 @@
+/**
+ * Test texturing with GL shading language.
+ *
+ * Copyright (C) 2007  Brian Paul   All Rights Reserved.
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
+ * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+
+#include <assert.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "GL/glut.h"
+#include "readtex.h"
+#include "extfuncs.h"
+
+static const char *Demo = "texdemo1";
+
+static const char *ReflectVertFile = "reflect.vert.txt";
+static const char *CubeFragFile = "cubemap.frag.txt";
+
+static const char *SimpleVertFile = "simple.vert.txt";
+static const char *SimpleTexFragFile = "shadowtex.frag.txt";
+
+static const char *GroundImage = "../images/tile.rgb";
+
+static GLuint Program1, Program2;
+
+static GLfloat TexXrot = 0, TexYrot = 0;
+static GLfloat Xrot = 20.0, Yrot = 20.0, Zrot = 0.0;
+static GLfloat EyeDist = 10;
+static GLboolean Anim = GL_TRUE;
+
+
+struct uniform_info {
+   const char *name;
+   GLuint size;
+   GLint location;
+   GLenum type;  /**< GL_FLOAT or GL_INT */
+   GLfloat value[4];
+};
+
+static struct uniform_info ReflectUniforms[] = {
+   { "cubeTex",  1, -1, GL_INT, { 0, 0, 0, 0 } },
+   { "lightPos", 3, -1, GL_FLOAT, { 10, 10, 20, 0 } },
+   { NULL, 0, 0, 0, { 0, 0, 0, 0 } }
+};
+
+static struct uniform_info SimpleUniforms[] = {
+   { "tex2d",    1, -1, GL_INT,   { 1, 0, 0, 0 } },
+   { "lightPos", 3, -1, GL_FLOAT, { 10, 10, 20, 0 } },
+   { NULL, 0, 0, 0, { 0, 0, 0, 0 } }
+};
+
+
+static void
+CheckError(int line)
+{
+   GLenum err = glGetError();
+   if (err) {
+      printf("GL Error %s (0x%x) at line %d\n",
+             gluErrorString(err), (int) err, line);
+   }
+}
+
+
+static void
+DrawGround(GLfloat size)
+{
+   glPushMatrix();
+   glRotatef(90, 1, 0, 0);
+   glNormal3f(0, 0, 1);
+   glBegin(GL_POLYGON);
+   glTexCoord2f(-2, -2);  glVertex2f(-size, -size);
+   glTexCoord2f( 2, -2);  glVertex2f( size, -size);
+   glTexCoord2f( 2,  2);  glVertex2f( size,  size);
+   glTexCoord2f(-2,  2);  glVertex2f(-size,  size);
+   glEnd();
+   glPopMatrix();
+}
+
+
+static void
+draw(void)
+{
+   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+   glEnable(GL_TEXTURE_2D);
+
+   glPushMatrix(); /* modelview matrix */
+      glTranslatef(0.0, 0.0, -EyeDist);
+      glRotatef(Xrot, 1, 0, 0);
+      glRotatef(Yrot, 0, 1, 0);
+      glRotatef(Zrot, 0, 0, 1);
+
+      /* sphere w/ reflection map */
+      glPushMatrix();
+         glTranslatef(0, 1, 0);
+         glUseProgram_func(Program1);
+
+         /* setup texture matrix */
+         glActiveTexture(GL_TEXTURE0);
+         glMatrixMode(GL_TEXTURE);
+         glLoadIdentity();
+         glRotatef(-TexYrot, 0, 1, 0);
+         glRotatef(-TexXrot, 1, 0, 0);
+
+         glEnable(GL_TEXTURE_GEN_S);
+         glEnable(GL_TEXTURE_GEN_T);
+         glEnable(GL_TEXTURE_GEN_R);
+         glutSolidSphere(2.0, 20, 20);
+
+         glLoadIdentity(); /* texture matrix */
+         glMatrixMode(GL_MODELVIEW);
+      glPopMatrix();
+
+      /* ground */
+      glUseProgram_func(Program2);
+      glTranslatef(0, -1.0, 0);
+      DrawGround(5);
+
+   glPopMatrix();
+
+   glutSwapBuffers();
+}
+
+
+static void
+idle(void)
+{
+   GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
+   TexYrot = t;
+   glutPostRedisplay();
+}
+
+
+static void
+key(unsigned char k, int x, int y)
+{
+   (void) x;
+   (void) y;
+   switch (k) {
+   case ' ':
+   case 'a':
+      Anim = !Anim;
+      if (Anim)
+         glutIdleFunc(idle);
+      else
+         glutIdleFunc(NULL);
+      break;
+   case 'z':
+      EyeDist -= 0.5;
+      if (EyeDist < 6.0)
+         EyeDist = 6.0;
+      break;
+   case 'Z':
+      EyeDist += 0.5;
+      if (EyeDist > 90.0)
+         EyeDist = 90;
+      break;
+   case 27:
+      exit(0);
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+specialkey(int key, int x, int y)
+{
+   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();
+}
+
+
+/* new window size or exposure */
+static void
+Reshape(int width, int height)
+{
+   GLfloat ar = (float) width / (float) height;
+   glViewport(0, 0, (GLint)width, (GLint)height);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glFrustum(-2.0*ar, 2.0*ar, -2.0, 2.0, 4.0, 100.0);
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+}
+
+
+static void
+InitCheckers(void)
+{
+#define CUBE_TEX_SIZE 64
+   GLubyte image[CUBE_TEX_SIZE][CUBE_TEX_SIZE][3];
+   static const GLubyte colors[6][3] = {
+      { 255,   0,   0 },	/* face 0 - red */
+      {   0, 255, 255 },	/* face 1 - cyan */
+      {   0, 255,   0 },	/* face 2 - green */
+      { 255,   0, 255 },	/* face 3 - purple */
+      {   0,   0, 255 },	/* face 4 - blue */
+      { 255, 255,   0 }		/* face 5 - yellow */
+   };
+   static const GLenum targets[6] = {
+      GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB,
+      GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB,
+      GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB,
+      GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB,
+      GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB,
+      GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB
+   };
+
+   GLint i, j, f;
+
+   glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+
+   /* make colored checkerboard cube faces */
+   for (f = 0; f < 6; f++) {
+      for (i = 0; i < CUBE_TEX_SIZE; i++) {
+         for (j = 0; j < CUBE_TEX_SIZE; j++) {
+            if ((i/4 + j/4) & 1) {
+               image[i][j][0] = colors[f][0];
+               image[i][j][1] = colors[f][1];
+               image[i][j][2] = colors[f][2];
+            }
+            else {
+               image[i][j][0] = 255;
+               image[i][j][1] = 255;
+               image[i][j][2] = 255;
+            }
+         }
+      }
+
+      glTexImage2D(targets[f], 0, GL_RGB, CUBE_TEX_SIZE, CUBE_TEX_SIZE, 0,
+                   GL_RGB, GL_UNSIGNED_BYTE, image);
+   }
+}
+
+
+static void
+LoadFace(GLenum target, const char *filename,
+         GLboolean flipTB, GLboolean flipLR)
+{
+   GLint w, h;
+   GLenum format;
+   GLubyte *img = LoadRGBImage(filename, &w, &h, &format);
+   if (!img) {
+      printf("Error: couldn't load texture image %s\n", filename);
+      exit(1);
+   }
+   assert(format == GL_RGB);
+
+   /* <sigh> the way the texture cube mapping works, we have to flip
+    * images to make things look right.
+    */
+   if (flipTB) {
+      const int stride = 3 * w;
+      GLubyte temp[3*1024];
+      int i;
+      for (i = 0; i < h / 2; i++) {
+         memcpy(temp, img + i * stride, stride);
+         memcpy(img + i * stride, img + (h - i - 1) * stride, stride);
+         memcpy(img + (h - i - 1) * stride, temp, stride);
+      }
+   }
+   if (flipLR) {
+      const int stride = 3 * w;
+      GLubyte temp[3];
+      GLubyte *row;
+      int i, j;
+      for (i = 0; i < h; i++) {
+         row = img + i * stride;
+         for (j = 0; j < w / 2; j++) {
+            int k = w - j - 1;
+            temp[0] = row[j*3+0];
+            temp[1] = row[j*3+1];
+            temp[2] = row[j*3+2];
+            row[j*3+0] = row[k*3+0];
+            row[j*3+1] = row[k*3+1];
+            row[j*3+2] = row[k*3+2];
+            row[k*3+0] = temp[0];
+            row[k*3+1] = temp[1];
+            row[k*3+2] = temp[2];
+         }
+      }
+   }
+
+   gluBuild2DMipmaps(target, GL_RGB, w, h, format, GL_UNSIGNED_BYTE, img);
+   free(img);
+}
+
+
+static void
+LoadEnvmaps(void)
+{
+   LoadFace(GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB, "right.rgb", GL_TRUE, GL_FALSE);
+   LoadFace(GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB, "left.rgb", GL_TRUE, GL_FALSE);
+   LoadFace(GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB, "top.rgb", GL_FALSE, GL_TRUE);
+   LoadFace(GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB, "bottom.rgb", GL_FALSE, GL_TRUE);
+   LoadFace(GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB, "front.rgb", GL_TRUE, GL_FALSE);
+   LoadFace(GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB, "back.rgb", GL_TRUE, GL_FALSE);
+}
+
+
+static void
+InitTextures(GLboolean useImageFiles)
+{
+   GLenum filter;
+
+   /*
+    * Env map
+    */
+   glActiveTexture(GL_TEXTURE0);
+   glBindTexture(GL_TEXTURE_CUBE_MAP, 1);
+   if (useImageFiles) {
+      LoadEnvmaps();
+      filter = GL_LINEAR;
+   }
+   else {
+      InitCheckers();
+      filter = GL_NEAREST;
+   }
+   glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, filter);
+   glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, filter);
+   glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+   glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+
+   /*
+    * Ground texture
+    */
+   {
+      GLint imgWidth, imgHeight;
+      GLenum imgFormat;
+      GLubyte *image = NULL;
+
+      image = LoadRGBImage(GroundImage, &imgWidth, &imgHeight, &imgFormat);
+      if (!image) {
+         printf("Couldn't read %s\n", GroundImage);
+         exit(0);
+      }
+
+      glActiveTexture(GL_TEXTURE1);
+      glBindTexture(GL_TEXTURE_2D, 2);
+      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);
+      glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+   }
+}
+
+
+static void
+LoadAndCompileShader(GLuint shader, const char *text)
+{
+   GLint stat;
+
+   glShaderSource_func(shader, 1, (const GLchar **) &text, NULL);
+
+   glCompileShader_func(shader);
+
+   glGetShaderiv_func(shader, GL_COMPILE_STATUS, &stat);
+   if (!stat) {
+      GLchar log[1000];
+      GLsizei len;
+      glGetShaderInfoLog_func(shader, 1000, &len, log);
+      fprintf(stderr, "%s: problem compiling shader: %s\n", Demo, log);
+      exit(1);
+   }
+   else {
+      printf("Shader compiled OK\n");
+   }
+}
+
+
+/**
+ * Read a shader from a file.
+ */
+static void
+ReadShader(GLuint shader, const char *filename)
+{
+   const int max = 100*1000;
+   int n;
+   char *buffer = (char*) malloc(max);
+   FILE *f = fopen(filename, "r");
+   if (!f) {
+      fprintf(stderr, "%s: Unable to open shader file %s\n", Demo, filename);
+      exit(1);
+   }
+
+   n = fread(buffer, 1, max, f);
+   printf("%s: read %d bytes from shader file %s\n", Demo, n, filename);
+   if (n > 0) {
+      buffer[n] = 0;
+      LoadAndCompileShader(shader, buffer);
+   }
+
+   fclose(f);
+   free(buffer);
+}
+
+
+static void
+CheckLink(GLuint prog)
+{
+   GLint stat;
+   glGetProgramiv_func(prog, GL_LINK_STATUS, &stat);
+   if (!stat) {
+      GLchar log[1000];
+      GLsizei len;
+      glGetProgramInfoLog_func(prog, 1000, &len, log);
+      fprintf(stderr, "Linker error:\n%s\n", log);
+   }
+   else {
+      fprintf(stderr, "Link success!\n");
+   }
+}
+
+
+static GLuint
+CreateProgram(const char *vertProgFile, const char *fragProgFile,
+              struct uniform_info *uniforms)
+{
+   GLuint fragShader = 0, vertShader = 0, program = 0;
+   GLint i;
+
+   program = glCreateProgram_func();
+   if (vertProgFile) {
+      vertShader = glCreateShader_func(GL_VERTEX_SHADER);
+      ReadShader(vertShader, vertProgFile);
+      glAttachShader_func(program, vertShader);
+   }
+
+   if (fragProgFile) {
+      fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
+      ReadShader(fragShader, fragProgFile);
+      glAttachShader_func(program, fragShader);
+   }
+
+   glLinkProgram_func(program);
+   CheckLink(program);
+
+   glUseProgram_func(program);
+
+   assert(glIsProgram_func(program));
+   assert(glIsShader_func(fragShader));
+   assert(glIsShader_func(vertShader));
+
+   CheckError(__LINE__);
+   for (i = 0; uniforms[i].name; i++) {
+      uniforms[i].location
+         = glGetUniformLocation_func(program, uniforms[i].name);
+      printf("Uniform %s location: %d\n", uniforms[i].name,
+             uniforms[i].location);
+
+      switch (uniforms[i].size) {
+      case 1:
+         if (uniforms[i].type == GL_INT)
+            glUniform1i_func(uniforms[i].location,
+                             (GLint) uniforms[i].value[0]);
+         else
+            glUniform1fv_func(uniforms[i].location, 1, uniforms[i].value);
+         break;
+      case 2:
+         glUniform2fv_func(uniforms[i].location, 1, uniforms[i].value);
+         break;
+      case 3:
+         glUniform3fv_func(uniforms[i].location, 1, uniforms[i].value);
+         break;
+      case 4:
+         glUniform4fv_func(uniforms[i].location, 1, uniforms[i].value);
+         break;
+      default:
+         abort();
+      }
+   }
+
+   CheckError(__LINE__);
+
+   return program;
+}
+
+
+static void
+InitPrograms(void)
+{
+   Program1 = CreateProgram(ReflectVertFile, CubeFragFile, ReflectUniforms);
+   Program2 = CreateProgram(SimpleVertFile, SimpleTexFragFile, SimpleUniforms);
+}
+
+
+static void
+Init(GLboolean useImageFiles)
+{
+   const char *version = (const char *) glGetString(GL_VERSION);
+
+   if (version[0] != '2' || version[1] != '.') {
+      printf("Warning: this program expects OpenGL 2.0\n");
+      /*exit(1);*/
+   }
+   printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+   GetExtensionFuncs();
+
+   InitTextures(useImageFiles);
+   InitPrograms();
+
+   glEnable(GL_DEPTH_TEST);
+
+   glClearColor(.6, .6, .9, 0);
+   glColor3f(1.0, 1.0, 1.0);
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   glutInit(&argc, argv);
+   glutInitWindowSize(500, 400);
+   glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
+   glutCreateWindow(Demo);
+   glutReshapeFunc(Reshape);
+   glutKeyboardFunc(key);
+   glutSpecialFunc(specialkey);
+   glutDisplayFunc(draw);
+   if (Anim)
+      glutIdleFunc(idle);
+   if (argc > 1 && strcmp(argv[1] , "-i") == 0)
+      Init(1);
+   else
+      Init(0);
+   glutMainLoop();
+   return 0;
+}