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-rw-r--r--progs/demos/fslight.c334
1 files changed, 334 insertions, 0 deletions
diff --git a/progs/demos/fslight.c b/progs/demos/fslight.c
new file mode 100644
index 0000000000..1c016cc75e
--- /dev/null
+++ b/progs/demos/fslight.c
@@ -0,0 +1,334 @@
+/**
+ * Test OpenGL 2.0 vertex/fragment shaders.
+ * Brian Paul
+ * 1 November 2006
+ *
+ * Based on ARB version by:
+ * Michal Krol
+ * 20 February 2006
+ *
+ * Based on the original demo by:
+ * Brian Paul
+ * 17 April 2003
+ */
+
+#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>
+
+static GLfloat diffuse[4] = { 0.5f, 0.5f, 1.0f, 1.0f };
+static GLfloat specular[4] = { 0.8f, 0.8f, 0.8f, 1.0f };
+static GLfloat lightPos[4] = { 0.0f, 10.0f, 20.0f, 1.0f };
+static GLfloat delta = 1.0f;
+
+static GLuint fragShader;
+static GLuint vertShader;
+static GLuint program;
+
+static GLint uLightPos;
+static GLint uDiffuse;
+static GLint uSpecular;
+
+static GLint win = 0;
+static GLboolean anim = GL_TRUE;
+static GLboolean wire = GL_FALSE;
+static GLboolean pixelLight = GL_TRUE;
+
+static GLint t0 = 0;
+static GLint frames = 0;
+
+static GLfloat xRot = 0.0f, yRot = 0.0f;
+
+static PFNGLCREATESHADERPROC glCreateShader_func = NULL;
+static PFNGLSHADERSOURCEPROC glShaderSource_func = NULL;
+static PFNGLGETSHADERSOURCEPROC glGetShaderSource_func = NULL;
+static PFNGLCOMPILESHADERPROC glCompileShader_func = NULL;
+static PFNGLCREATEPROGRAMPROC glCreateProgram_func = NULL;
+static PFNGLDELETEPROGRAMPROC glDeleteProgram_func = NULL;
+static PFNGLDELETESHADERPROC glDeleteShader_func = NULL;
+static PFNGLATTACHSHADERPROC glAttachShader_func = NULL;
+static PFNGLLINKPROGRAMPROC glLinkProgram_func = NULL;
+static PFNGLUSEPROGRAMPROC glUseProgram_func = NULL;
+static PFNGLGETUNIFORMLOCATIONPROC glGetUniformLocation_func = NULL;
+static PFNGLISPROGRAMPROC glIsProgram_func = NULL;
+static PFNGLISSHADERPROC glIsShader_func = NULL;
+static PFNGLUNIFORM3FVPROC glUniform3fv_func = NULL;
+static PFNGLUNIFORM3FVPROC glUniform4fv_func = NULL;
+
+
+
+static void
+normalize(GLfloat *dst, const GLfloat *src)
+{
+ GLfloat len = sqrtf(src[0] * src[0] + src[1] * src[1] + src[2] * src[2]);
+ dst[0] = src[0] / len;
+ dst[1] = src[1] / len;
+ dst[2] = src[2] / len;
+}
+
+
+static void
+Redisplay(void)
+{
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+ if (pixelLight) {
+ GLfloat vec[3];
+ glUseProgram_func(program);
+ normalize(vec, lightPos);
+ glUniform3fv_func(uLightPos, 1, vec);
+ glDisable(GL_LIGHTING);
+ }
+ else {
+ glUseProgram_func(0);
+ glLightfv(GL_LIGHT0, GL_POSITION, lightPos);
+ glEnable(GL_LIGHTING);
+ }
+
+ glPushMatrix();
+ glRotatef(xRot, 1.0f, 0.0f, 0.0f);
+ glRotatef(yRot, 0.0f, 1.0f, 0.0f);
+ glutSolidSphere(2.0, 10, 5);
+ glPopMatrix();
+
+ glutSwapBuffers();
+ frames++;
+
+ if (anim) {
+ GLint t = glutGet(GLUT_ELAPSED_TIME);
+ if (t - t0 >= 5000) {
+ GLfloat seconds =(GLfloat)(t - t0) / 1000.0f;
+ GLfloat fps = frames / seconds;
+ printf("%d frames in %6.3f seconds = %6.3f FPS\n",
+ frames, seconds, fps);
+ t0 = t;
+ frames = 0;
+ }
+ }
+}
+
+
+static void
+Idle(void)
+{
+ lightPos[0] += delta;
+ if (lightPos[0] > 25.0f || lightPos[0] < -25.0f)
+ delta = -delta;
+ 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 'x':
+ lightPos[0] -= 1.0f;
+ break;
+ case 'X':
+ lightPos[0] += 1.0f;
+ break;
+ case 'w':
+ wire = !wire;
+ if (wire)
+ glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+ else
+ glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
+ break;
+ case 'p':
+ pixelLight = !pixelLight;
+ if (pixelLight)
+ printf("Per-pixel lighting\n");
+ else
+ printf("Conventional lighting\n");
+ 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
+Init(void)
+{
+ static const char *fragShaderText =
+ "uniform vec3 lightPos;\n"
+ "uniform vec4 diffuse;\n"
+ "uniform vec4 specular;\n"
+ "varying vec3 normal;\n"
+ "void main() {\n"
+ " // Compute dot product of light direction and normal vector\n"
+ " float dotProd = max(dot(lightPos, normalize(normal)), 0.0);\n"
+ " // Compute diffuse and specular contributions\n"
+ " gl_FragColor = diffuse * dotProd + specular * pow(dotProd, 20.0);\n"
+ "}\n";
+ static const char *vertShaderText =
+ "varying vec3 normal;\n"
+ "void main() {\n"
+ " gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
+ " normal = gl_NormalMatrix * gl_Normal;\n"
+ "}\n";
+
+
+ const char *version;
+
+ version = (const char *) glGetString(GL_VERSION);
+ if (version[0] != '2' || version[1] != '.') {
+ printf("Warning: this program expects OpenGL 2.0\n");
+ /*exit(1);*/
+ }
+
+
+ glCreateShader_func = (PFNGLCREATESHADERPROC) glutGetProcAddress("glCreateShader");
+ glDeleteShader_func = (PFNGLDELETESHADERPROC) glutGetProcAddress("glDeleteShader");
+ glDeleteProgram_func = (PFNGLDELETEPROGRAMPROC) glutGetProcAddress("glDeleteProgram");
+ glShaderSource_func = (PFNGLSHADERSOURCEPROC) glutGetProcAddress("glShaderSource");
+ glGetShaderSource_func = (PFNGLGETSHADERSOURCEPROC) glutGetProcAddress("glGetShaderSource");
+ glCompileShader_func = (PFNGLCOMPILESHADERPROC) glutGetProcAddress("glCompileShader");
+ glCreateProgram_func = (PFNGLCREATEPROGRAMPROC) glutGetProcAddress("glCreateProgram");
+ glAttachShader_func = (PFNGLATTACHSHADERPROC) glutGetProcAddress("glAttachShader");
+ glLinkProgram_func = (PFNGLLINKPROGRAMPROC) glutGetProcAddress("glLinkProgram");
+ glUseProgram_func = (PFNGLUSEPROGRAMPROC) glutGetProcAddress("glUseProgram");
+ glGetUniformLocation_func = (PFNGLGETUNIFORMLOCATIONPROC) glutGetProcAddress("glGetUniformLocation");
+ glIsProgram_func = (PFNGLISPROGRAMPROC) glutGetProcAddress("glIsProgram");
+ glIsShader_func = (PFNGLISSHADERPROC) glutGetProcAddress("glIsShader");
+ glUniform3fv_func = (PFNGLUNIFORM3FVPROC) glutGetProcAddress("glUniform3fv");
+ glUniform4fv_func = (PFNGLUNIFORM3FVPROC) glutGetProcAddress("glUniform4fv");
+
+ fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
+ glShaderSource_func(fragShader, 1, &fragShaderText, NULL);
+ glCompileShader_func(fragShader);
+
+ vertShader = glCreateShader_func(GL_VERTEX_SHADER);
+ glShaderSource_func(vertShader, 1, &vertShaderText, NULL);
+ glCompileShader_func(vertShader);
+
+ program = glCreateProgram_func();
+ glAttachShader_func(program, fragShader);
+ glAttachShader_func(program, vertShader);
+ glLinkProgram_func(program);
+ glUseProgram_func(program);
+
+ uLightPos = glGetUniformLocation_func(program, "lightPos");
+ uDiffuse = glGetUniformLocation_func(program, "diffuse");
+ uSpecular = glGetUniformLocation_func(program, "specular");
+
+ glUniform4fv_func(uDiffuse, 1, diffuse);
+ glUniform4fv_func(uSpecular, 1, specular);
+
+ glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
+ glEnable(GL_DEPTH_TEST);
+ glEnable(GL_LIGHT0);
+ glEnable(GL_LIGHTING);
+ glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, diffuse);
+ glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
+ glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 20.0f);
+
+ printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+ printf("Press p to toggle between per-pixel and per-vertex lighting\n");
+
+ /* test glGetShaderSource() */
+ {
+ GLsizei len = strlen(fragShaderText) + 1;
+ GLsizei lenOut;
+ GLchar *src =(GLchar *) malloc(len * sizeof(GLchar));
+ glGetShaderSource_func(fragShader, 0, NULL, src);
+ glGetShaderSource_func(fragShader, len, &lenOut, src);
+ assert(len == lenOut + 1);
+ assert(strcmp(src, fragShaderText) == 0);
+ free(src);
+ }
+
+ assert(glIsProgram_func(program));
+ assert(glIsShader_func(fragShader));
+ assert(glIsShader_func(vertShader));
+}
+
+
+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);
+ Init();
+ glutMainLoop();
+ return 0;
+}
+
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