progs/glsl: better comments

[mesa.git] / progs / glsl / points.c

diff --git a/progs/glsl/points.c b/progs/glsl/points.c
index 85115de504a2739410779b7ac4496020e6b90bf0..98490f1819c781cd2d714de751cdeb3f78476cd1 100644 (file)
--- a/progs/glsl/points.c
+++ b/progs/glsl/points.c
@@ -10,10 +10,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <math.h>
-#include <GL/gl.h>
+#include <GL/glew.h>
 #include <GL/glut.h>
-#include <GL/glext.h>
-#include "extfuncs.h"
+#include "shaderutil.h"
 
 
 static GLuint FragShader;
@@ -72,8 +71,8 @@ DrawPoints(GLboolean shaderPoints)
 
 
 /**
- * Top row of points rendered convetionally,
- * bottom row rendered with shaders.
+ * Top row of points is rendered conventionally with GL_POINT_SMOOTH.
+ * Bottom row is rendered with special vertex/fragment shaders (see Init()).
  */
 static void
 Redisplay(void)
@@ -98,7 +97,7 @@ Redisplay(void)
     */
    glPushMatrix();
    glTranslatef(0, 1.2, 0);
-   glUseProgram_func(0);
+   glUseProgram(0);
    DrawPoints(GL_FALSE);
    glPopMatrix();
 
@@ -107,9 +106,9 @@ Redisplay(void)
     */
    glPushMatrix();
    glTranslatef(0, -1.2, 0);
-   glUseProgram_func(Program);
+   glUseProgram(Program);
    if (uViewportInv != -1) {
-      glUniform2f_func(uViewportInv, 1.0 / WinWidth, 1.0 / WinHeight);
+      glUniform2f(uViewportInv, 1.0 / WinWidth, 1.0 / WinHeight);
    }
    DrawPoints(GL_TRUE);
    glPopMatrix();
@@ -149,9 +148,9 @@ Key(unsigned char key, int x, int y)
       Smooth = !Smooth;
       break;
    case 27:
-      glDeleteShader_func(FragShader);
-      glDeleteShader_func(VertShader);
-      glDeleteProgram_func(Program);
+      glDeleteShader(FragShader);
+      glDeleteShader(VertShader);
+      glDeleteProgram(Program);
       glutDestroyWindow(Win);
       exit(0);
    }
@@ -181,40 +180,6 @@ SpecialKey(int key, int x, int y)
 }
 
 
-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)
 {
@@ -254,33 +219,19 @@ Init(void)
       "   gl_TexCoord[0] = gl_MultiTexCoord0; \n"
       "   gl_FrontColor = gl_Color; \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);
+   if (!ShadersSupported())
       exit(1);
-   }
-   printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
-
-   GetExtensionFuncs();
-
-   FragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
-   LoadAndCompileShader(FragShader, fragShaderText);
 
-   VertShader = glCreateShader_func(GL_VERTEX_SHADER);
-   LoadAndCompileShader(VertShader, vertShaderText);
+   VertShader = CompileShaderText(GL_VERTEX_SHADER, vertShaderText);
+   FragShader = CompileShaderText(GL_FRAGMENT_SHADER, fragShaderText);
+   Program = LinkShaders(VertShader, FragShader);
 
-   Program = glCreateProgram_func();
-   glAttachShader_func(Program, FragShader);
-   glAttachShader_func(Program, VertShader);
-   glLinkProgram_func(Program);
-   CheckLink(Program);
-   glUseProgram_func(Program);
+   glUseProgram(Program);
 
-   uViewportInv = glGetUniformLocation_func(Program, "viewportInv");
+   uViewportInv = glGetUniformLocation(Program, "viewportInv");
 
-   glUseProgram_func(0);
+   glUseProgram(0);
 
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
 }
@@ -293,6 +244,7 @@ main(int argc, char *argv[])
    glutInitWindowSize(WinWidth, WinHeight);
    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
    Win = glutCreateWindow(argv[0]);
+   glewInit();
    glutReshapeFunc(Reshape);
    glutKeyboardFunc(Key);
    glutSpecialFunc(SpecialKey);