转换GLSL现代OpenGL 3.2

我正在使用Xcode 5运行10.9的mac上学习关于wikibooks的免费教程。我用着色器版本120运行它，但我想使用一些现代功能，所以我将SDL提示设置为OpenGL 3.2，并将着色器转换为150。问题是在版本150中，使用texture2D将阻止着色器编译。

以下是着色器的版本120：

const GLchar* vTextSource =
"#version 120n"
"attribute vec4 coord;"
"varying vec2 texcoord;"
"void main(void) {"
"  gl_Position = vec4(coord.xy, 0, 1);"
"  texcoord = coord.zw;"
"}";
const GLchar* fTextSource =
"#version 120n"
"varying vec2 texcoord;"
"uniform sampler2D tex;"
"uniform vec4 color;"
"void main(void) {"
"  gl_FragColor = vec4(1,1,0, texture2D(tex, texcoord).a) * color;"
"}";

这就是我的150版本。顶点着色器会生成，但片段着色器会失败，除非我删除texture2D的任何使用。它们之间的所有CPU代码都是相同的。

const GLchar* vTextSource =
"#version 150 n"
"in vec4 coord;"
"out vec2 texcoord;"
"void main(void) {"
"  gl_Position = vec4(coord.xy, 0, 1);"
"  texcoord = coord.zw;"
"}";
const GLchar* fTextSource =
"#version 150n"
"uniform sampler2D tex;"
"in vec2 texcoord;"
"uniform vec4 color;"
"out vec4 outColor;"
"void main(void) {"
"  outColor = vec4(1,1,1, texture2D(tex, texcoord).a) * color;"
"}";

我有什么东西不见了吗？在核心配置文件中设置纹理采样器是否与在兼容模式中不同？

编辑：我已经在片段着色器中从texture2D（…）更改为texture（…）。它现在正在编译，但什么也没显示。我不知道如何调试它。我已经包含了纹理初始化例程：

void SdlApplication::render_text(const char *text, float x, float y, float sx, float sy) {
    const char *p;
    FT_GlyphSlot g = face->glyph;
    /* Create a texture that will be used to hold one "glyph" */
    GLuint tex;
    glActiveTexture(GL_TEXTURE0);
    glGenTextures(1, &tex);
    glBindTexture(GL_TEXTURE_2D, tex);
    glUniform1i(ogl.uniform_tex, 0);
    /* We require 1 byte alignment when uploading texture data */
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
    /* Clamping to edges is important to prevent artifacts when scaling */
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
    /* Linear filtering usually looks best for text */
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    /* Set up the VBO for our vertex data */
    glEnableVertexAttribArray(ogl.attribute_coord);
    glBindBuffer(GL_ARRAY_BUFFER, vboText);
    glVertexAttribPointer(ogl.attribute_coord, 4, GL_FLOAT, GL_FALSE, 0, 0);
    /* Loop through all characters */
    for (p = text; *p; p++) {
        /* Try to load and render the character */
        if (FT_Load_Char(face, *p, FT_LOAD_RENDER))
            continue;
        /* Upload the "bitmap", which contains an 8-bit grayscale image, as an alpha texture */
        glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, g->bitmap.width, g->bitmap.rows, 0, GL_ALPHA, GL_UNSIGNED_BYTE, g->bitmap.buffer);
        /* Calculate the vertex and texture coordinates */
        float x2 = x + g->bitmap_left * sx;
        float y2 = -y - g->bitmap_top * sy;
        float w = g->bitmap.width * sx;
        float h = g->bitmap.rows * sy;
        point box[4] = {
            {x2, -y2, 0, 0},
            {x2 + w, -y2, 1, 0},
            {x2, -y2 - h, 0, 1},
            {x2 + w, -y2 - h, 1, 1},
        };
        /* Draw the character on the screen */
        glBufferData(GL_ARRAY_BUFFER, sizeof box, box, GL_DYNAMIC_DRAW);
        glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
        /* Advance the cursor to the start of the next character */
        x += (g->advance.x >> 6) * sx;
        y += (g->advance.y >> 6) * sy;
    }
    glDisableVertexAttribArray(ogl.attribute_coord);
    glDeleteTextures(1, &tex);
}

编辑2：将vao添加到我的顶点设置中。我现在在文本应该在的地方得到了纯色的正方形。所以看起来纹理坐标又乱了。

我在每次调用后都添加了检查，发现我在glewInit之后得到了1280代码，但在。。。