Opengl 实现使用统一采样器2D(lwjgl)的片段着色器
我无法成功运行着色器,而且我似乎错过了使其正常工作的一些步骤。我最后的错误是:Opengl 实现使用统一采样器2D(lwjgl)的片段着色器,opengl,lwjgl,fragment-shader,Opengl,Lwjgl,Fragment Shader,我无法成功运行着色器,而且我似乎错过了使其正常工作的一些步骤。我最后的错误是: Exception in thread "main" org.lwjgl.opengl.OpenGLException: Invalid operation (1282) at org.lwjgl.opengl.Util.checkGLError(Util.java:59) at org.lwjgl.opengl.GL20.glUniform1i(GL20.java:374) at sprit
Exception in thread "main" org.lwjgl.opengl.OpenGLException: Invalid operation (1282)
at org.lwjgl.opengl.Util.checkGLError(Util.java:59)
at org.lwjgl.opengl.GL20.glUniform1i(GL20.java:374)
at sprites.Sprite.draw(Sprite.java:256)
at gui.Game.drawFrame(Game.java:238)
at gui.Game.gameLoop(Game.java:205)
at gui.Game.startGame(Game.java:244)
at tests.simple.SimpleShader.main(SimpleShader.java:36)
我的初始化从以下内容开始:
int frag = FilterLoader.createShader("/tests/resources/shaders/grayscale.frag", GL20.GL_FRAGMENT_SHADER);
createShader方法如下所示:
int shader = GL20.glCreateShader(type);
if(shader == 0)
return 0;
StringBuilder code = new StringBuilder("");
String line;
try
{
String path = FilterLoader.class.getResource(filename).getPath();
BufferedReader reader = new BufferedReader(new FileReader(path));
while((line = reader.readLine()) != null)
{
code.append(line + "\n");
}
}
catch(Exception e)
{
e.printStackTrace();
System.err.println("Error reading in " + type + " shader");
return 0;
}
GL20.glShaderSource(shader, code);
GL20.glCompileShader(shader);
return shader;
然后,我使用以下方法将着色器附加到特定精灵:
two.addFragmentShader(frag); //two is a Sprite
这很简单:
fragmentShader = fragment_shader;
GL20.glAttachShader(shader, fragment_shader);
GL20.glLinkProgram(shader);
int着色器以前已在Sprites构造函数中使用以下命令初始化:
shader = GL20.glCreateProgram();
这是以前的问题,但不再明显。现在我看到了实际错误发生的地方,在sprite(本例中为两个)draw方法中,如下所示:
if(true)
{
GL20.glUseProgram(shader);
}
glPushMatrix();
glActiveTexture(GL13.GL_TEXTURE0);
imageData.getTexture().bind();
//The line below is where the error occurs.
GL20.glUniform1i(fragmentShader, GL13.GL_TEXTURE0);
int tx = (int)location.x;
int ty = (int)location.y;
glTranslatef(tx, ty, location.layer);
float texture_X = ((float)which_column/(float)columns);
float texture_Y = ((float)which_row/(float)rows);
float texture_XplusWidth = ((float)(which_column+wide)/(float)columns);
float texture_YplusHeight = ((float)(which_row+tall)/(float)rows);
glBegin(GL_QUADS);
{
GL11.glTexCoord2f(texture_X, texture_Y);
glVertex2f(0, 0);
GL11.glTexCoord2f(texture_X, texture_YplusHeight);
glVertex2f(0, getHeight());
GL11.glTexCoord2f(texture_XplusWidth, texture_YplusHeight);
glVertex2f(getWidth(), getHeight());
GL11.glTexCoord2f(texture_XplusWidth, texture_Y);
glVertex2f(getWidth(), 0);
}
glEnd();
GL20.glUseProgram(0);
glPopMatrix();
错误发生在这一行:
GL20.glUniform1i(fragmentShader, GL13.GL_TEXTURE0);
作为我的着色器的参考:
// simple fragment shader
uniform sampler2D texture;
void main()
{
vec4 color, texel;
color = gl_Color;
texel = texture2DRect(texture, gl_TexCoord[0].xy);
color *= texel;
float gray = dot(color.rgb, vec3(0.299, 0.587, 0.144));
gl_FragColor = vec4(gray, gray, gray, color.a);
}
我已经阅读了教程,阅读了有关错误的信息,但我不知道我错过了哪一步
GL20.glUniform1i(fragmentShader, GL13.GL_TEXTURE0);
这是错误的。glUniform1i
的第一个参数是统一位置,您可以使用glGetUniformLocation
获得该位置
第二个参数是整数,但对于纹理采样器,需要传递纹理单元编号(0、1、2等),并将纹理绑定到该纹理单元,例如:
glUseProgram(program);
int loc = glGetUniformLocation(program, "texture");
glUniform1i(loc, 0);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D, texId);
然后它应该可以工作。新的位:int loc=glGet。。。。正在抛出相同的错误,似乎是链接错误。@Atrus链接错误通过glGetProgramInfoLog报告,是否检查着色器编译和链接是否成功?我使用了GL20.glGetProgramInfoLog(着色器,4096)。它什么也没印出来。我试着把它放在不同的区域之后(特别是在:glAttachShader、glLinkProgram和glValidateProgram之后)。什么都没有。