add guMakeShaderFromFile() and guMakeShader()

glslUtil/glslUtil.c

@@ -1,4 +1,5 @@
 
+#include <stdio.h>
 #include <stdlib.h>
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -215,3 +216,51 @@ char *guGetProgramLog(GLuint id)
     }
     return NULL;
 }
+
+GLuint guMakeShaderFromFile(GLenum shaderType, const char *fname)
+{
+    char *source;
+    source = loadFile(fname);
+    if (source == NULL)
+    {
+        fprintf(stderr, "Error reading file '%s'\n", fname);
+        return 0;
+    }
+    GLuint id = guMakeShader(shaderType, source);
+    free(source);
+    return id;
+}
+
+GLuint guMakeShader(GLenum shaderType, const char *source)
+{
+    GLuint id;
+    GLint status;
+
+    id = glCreateShader(shaderType);
+    if (id <= 0)
+    {
+        fprintf(stderr, "Error creating shader object\n");
+        goto out;
+    }
+
+    glShaderSource(id, 1, &source, NULL);
+
+    glCompileShader(id);
+
+    glGetShaderiv(id, GL_COMPILE_STATUS, &status);
+    if (status != GL_TRUE)
+    {
+        fprintf(stderr, "Error compiling shader\n");
+        char *log = guGetShaderLog(id);
+        fprintf(stderr, "Shader Log:\n%s\n", log);
+        free(log);
+        goto cleanup_shader;
+    }
+
+    return id;
+
+cleanup_shader:
+    glDeleteShader(id);
+out:
+    return 0;
+}

glslUtil/glslUtil.h

@@ -32,6 +32,8 @@ void guOrtho(guMatrix4x4 *m,
         GLfloat near, GLfloat far);
 char *guGetShaderLog(GLuint id);
 char *guGetProgramLog(GLuint id);
+GLuint guMakeShaderFromFile(GLenum shaderType, const char *fname);
+GLuint guMakeShader(GLenum shaderType, const char *source);
 
 #ifdef __cplusplus
 }