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-rw-r--r--progs/glsl/Makefile1
-rw-r--r--progs/glsl/deriv.c321
2 files changed, 322 insertions, 0 deletions
diff --git a/progs/glsl/Makefile b/progs/glsl/Makefile
index e08d4102c8..b51a2a32b4 100644
--- a/progs/glsl/Makefile
+++ b/progs/glsl/Makefile
@@ -16,6 +16,7 @@ LIB_DEP = $(TOP)/$(LIB_DIR)/$(GL_LIB_NAME) $(TOP)/$(LIB_DIR)/$(GLU_LIB_NAME) $(T
PROGS = \
brick \
bump \
+ deriv \
mandelbrot \
noise \
toyball \
diff --git a/progs/glsl/deriv.c b/progs/glsl/deriv.c
new file mode 100644
index 0000000000..63beef1c94
--- /dev/null
+++ b/progs/glsl/deriv.c
@@ -0,0 +1,321 @@
+/**
+ * Test OpenGL 2.0 dx/dy functions for texcoords.
+ * Brian Paul
+ * 2 May 2007
+ *
+ * NOTE: resize the window to observe how the partial derivatives of
+ * the texcoords change.
+ */
+
+
+#include <assert.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/gl.h>
+#include <GL/glut.h>
+#include <GL/glext.h>
+#include "extfuncs.h"
+
+
+static char *FragProgFile = NULL;
+static char *VertProgFile = NULL;
+static GLuint fragShader;
+static GLuint vertShader;
+static GLuint program;
+static GLuint SphereList, RectList, CurList;
+static GLint win = 0;
+static GLboolean anim = GL_TRUE;
+static GLfloat xRot = 0.0f, yRot = 0.0f;
+
+
+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);
+ glCallList(CurList);
+ glPopMatrix();
+
+ glutSwapBuffers();
+}
+
+
+static void
+Idle(void)
+{
+ yRot = glutGet(GLUT_ELAPSED_TIME) * 0.1;
+ glutPostRedisplay();
+}
+
+
+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_func(fragShader);
+ glDeleteShader_func(vertShader);
+ glDeleteProgram_func(program);
+ glutDestroyWindow(win);
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+ (void) x;
+ (void) y;
+
+ switch(key) {
+ case ' ':
+ case 'a':
+ anim = !anim;
+ if (anim)
+ glutIdleFunc(Idle);
+ else
+ glutIdleFunc(NULL);
+ break;
+ case 'o':
+ if (CurList == SphereList)
+ CurList = RectList;
+ else
+ CurList = SphereList;
+ break;
+ case 27:
+ CleanUp();
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+SpecialKey(int key, int x, int y)
+{
+ const GLfloat step = 3.0f;
+
+ (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
+MakeSphere(void)
+{
+ GLUquadricObj *obj = gluNewQuadric();
+ SphereList = glGenLists(1);
+ gluQuadricTexture(obj, GL_TRUE);
+ glNewList(SphereList, GL_COMPILE);
+ gluSphere(obj, 2.0f, 30, 15);
+ glEndList();
+}
+
+
+static void
+MakeRect(void)
+{
+ RectList = glGenLists(1);
+ glNewList(RectList, GL_COMPILE);
+ glNormal3f(0, 0, 1);
+ glBegin(GL_POLYGON);
+ glTexCoord2f(0, 0); glVertex2f(-2, -2);
+ glTexCoord2f(1, 0); glVertex2f( 2, -2);
+ glTexCoord2f(1, 1); glVertex2f( 2, 2);
+ glTexCoord2f(0, 1); glVertex2f(-2, 2);
+ glEnd();
+ glEndList();
+}
+
+
+
+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, "fslight: problem compiling shader:\n%s\n", log);
+ exit(1);
+ }
+}
+
+
+/**
+ * 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, "fslight: Unable to open shader file %s\n", filename);
+ exit(1);
+ }
+
+ n = fread(buffer, 1, max, f);
+ printf("fslight: read %d bytes from shader file %s\n", 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);
+ }
+}
+
+
+static void
+Init(void)
+{
+ static const char *fragShaderText =
+ "void main() {\n"
+ " gl_FragColor = abs(dFdy(gl_TexCoord[0])) * 50.0;\n"
+ " // gl_FragColor = gl_TexCoord[0];\n"
+ "}\n";
+ static const char *vertShaderText =
+ "varying vec3 normal;\n"
+ "void main() {\n"
+ " gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
+ " gl_TexCoord[0] = gl_MultiTexCoord0;\n"
+ "}\n";
+ const char *version;
+
+ version = (const char *) glGetString(GL_VERSION);
+ if (version[0] != '2' || version[1] != '.') {
+ printf("This program requires OpenGL 2.x, found %s\n", version);
+ exit(1);
+ }
+
+ GetExtensionFuncs();
+
+ fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
+ if (FragProgFile)
+ ReadShader(fragShader, FragProgFile);
+ else
+ LoadAndCompileShader(fragShader, fragShaderText);
+
+ vertShader = glCreateShader_func(GL_VERTEX_SHADER);
+ if (VertProgFile)
+ ReadShader(vertShader, VertProgFile);
+ else
+ LoadAndCompileShader(vertShader, vertShaderText);
+
+ program = glCreateProgram_func();
+ glAttachShader_func(program, fragShader);
+ glAttachShader_func(program, vertShader);
+ glLinkProgram_func(program);
+ CheckLink(program);
+ glUseProgram_func(program);
+
+ /*assert(glGetError() == 0);*/
+
+ glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
+ glEnable(GL_DEPTH_TEST);
+
+ MakeSphere();
+ MakeRect();
+
+ CurList = SphereList;
+
+ printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+
+ assert(glIsProgram_func(program));
+ assert(glIsShader_func(fragShader));
+ assert(glIsShader_func(vertShader));
+
+ glColor3f(1, 0, 0);
+}
+
+
+static void
+ParseOptions(int argc, char *argv[])
+{
+ int i;
+ for (i = 1; i < argc; i++) {
+ if (strcmp(argv[i], "-fs") == 0) {
+ FragProgFile = argv[i+1];
+ }
+ else if (strcmp(argv[i], "-vs") == 0) {
+ VertProgFile = argv[i+1];
+ }
+ }
+}
+
+
+int
+main(int argc, char *argv[])
+{
+ glutInit(&argc, argv);
+ glutInitWindowPosition( 0, 0);
+ glutInitWindowSize(200, 200);
+ glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
+ win = glutCreateWindow(argv[0]);
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutSpecialFunc(SpecialKey);
+ glutDisplayFunc(Redisplay);
+ if (anim)
+ glutIdleFunc(Idle);
+ ParseOptions(argc, argv);
+ Init();
+ glutMainLoop();
+ return 0;
+}