c - OpenGL如何从程序中设置着色器纹理(sampler2D)

Question

我想将 GLSL 着色器中的 2 个纹理合并为 1 个。

问题是我无法从我的程序中设置着色器中的sampler2D。 (着色器/程序编译正确，纹理加载正确，顶点着色器也正确)我使用教程中的以下代码进行了尝试:

glUniform1i(program.getUniformLocation("Texture0"), 0);
glUniform1i(program.getUniformLocation("Texture1"), 1);

//texture 0, first texture
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, colorTexture.handle);

//texture 1, other texture
glActiveTexture(GL_TEXTURE1);
glBindTexture(GL_TEXTURE_2D, normalTexture.handle);

片段着色器代码如下所示

uniform sampler2D Texture0;
uniform sampler2D Texture1;

void main(void)
{
    vec4 color = texture2D(Texture0, vec2(gl_TexCoord[0]));
    vec4 normal = texture2D(Texture1, vec2(gl_TexCoord[0]));
    gl_FragColor = normal + color;
}

它被绘制

glUseProgram(program.handle);
glColor3f(1, 1, 1);
    glBegin(GL_QUADS);
    glTexCoord2f(0, 0);
    glVertex3f(0, 0, 0);
    glTexCoord2f(1, 0);
    glVertex3f(500, 0, 0);
    glTexCoord2f(1, 1);
    glVertex3f(500, 500, 0);
    glTexCoord2f(0, 1);
    glVertex3f(0, 500, 0);
    glEnd();

Answer 1

尝试更改第二个采样器以使用 gl_TexCoord[1]

uniform sampler2D Texture0;
uniform sampler2D Texture1;

void main(void)
{
    vec4 color = texture2D(Texture0, vec2(gl_TexCoord[0]));
    vec4 normal = texture2D(Texture1, vec2(gl_TexCoord[1]));
    gl_FragColor = normal + color;
}