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-rw-r--r--progs/trivial/fs-tri.c207
1 files changed, 207 insertions, 0 deletions
diff --git a/progs/trivial/fs-tri.c b/progs/trivial/fs-tri.c
new file mode 100644
index 0000000000..ecb13fd56d
--- /dev/null
+++ b/progs/trivial/fs-tri.c
@@ -0,0 +1,207 @@
+/* Test fragment shader */
+
+#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 GLuint fragShader;
+static GLuint vertShader;
+static GLuint program;
+static GLint win = 0;
+static GLfloat xpos = 0, ypos = 0;
+
+
+static void
+Redisplay(void)
+{
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+ glPushMatrix();
+ glTranslatef(xpos, ypos, 0);
+
+ glBegin(GL_TRIANGLES);
+ glVertex2f(-0.9, -0.9);
+ glVertex2f( 0.9, -0.9);
+ glVertex2f( 0, 0.9);
+ glEnd();
+
+ glPopMatrix();
+
+ glutSwapBuffers();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+ glViewport(0, 0, width, height);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glOrtho(-1, 1, -1, 1, -1, 1);
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+}
+
+
+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 27:
+ CleanUp();
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+SpecialKey(int key, int x, int y)
+{
+ const GLfloat step = 0.1;
+
+ (void) x;
+ (void) y;
+
+ switch(key) {
+ case GLUT_KEY_UP:
+ ypos += step;
+ break;
+ case GLUT_KEY_DOWN:
+ ypos -= step;
+ break;
+ case GLUT_KEY_LEFT:
+ xpos -= step;
+ break;
+ case GLUT_KEY_RIGHT:
+ xpos += step;
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+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);
+ }
+}
+
+
+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)
+{
+ /* fragment color is a function of fragment position: */
+ static const char *fragShaderText =
+ "void main() {\n"
+ " gl_FragColor = gl_FragCoord * vec4(0.005); \n"
+ "}\n";
+#if 0
+ 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";
+#endif
+ 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);
+ LoadAndCompileShader(fragShader, fragShaderText);
+
+#if 0
+ vertShader = glCreateShader_func(GL_VERTEX_SHADER);
+ LoadAndCompileShader(vertShader, vertShaderText);
+#endif
+
+ program = glCreateProgram_func();
+ glAttachShader_func(program, fragShader);
+#if 0
+ glAttachShader_func(program, vertShader);
+#endif
+ glLinkProgram_func(program);
+ CheckLink(program);
+ glUseProgram_func(program);
+
+ assert(glGetError() == 0);
+
+ glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
+
+ printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
+}
+
+
+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);
+ Init();
+ glutMainLoop();
+ return 0;
+}
+
+