I am currently trying to create a Blur Shader for postprocessing purposes using LWJGL, but stumbled across a problem.
The Uniforms I want to change are resolution, radius and direction of the blur (horizontal or vertical, so I am able to use one Shader for both directions). I render the output to a FrameBuffer, which then gets rendered to the screen. But somehow, the Texture is just black. When I use constant values instead of uniforms, it works exactly as expected, so the problem must be the uniform variables.
This is the code of my fragment shader:
#version 330 core
out vec4 fragColor;
in vec2 coords;
in vec4 color;
in float samplerIndex;
uniform sampler2D samplers[32]; //Just an Array with ints from 0 to 31
uniform float radius;
uniform vec2 resolution; //Screen Resolution, or width & height of Framebuffer
uniform vec2 direction; //Either 1 or 0 for x and y
void main() {
int index = int(samplerIndex);
vec4 sum = vec4(0.0);
float blurX = radius / resolution.x * direction.x;
float blurY = radius / resolution.y * direction.y;
sum += texture2D(samplers[index], vec2(coords.x - 4.0 * blurX, coords.y - 4.0 * blurY)) * 0.0162162162;
sum += texture2D(samplers[index], vec2(coords.x - 3.0 * blurX, coords.y - 3.0 * blurY)) * 0.0540540541;
sum += texture2D(samplers[index], vec2(coords.x - 2.0 * blurX, coords.y - 2.0 * blurY)) * 0.1216216216;
sum += texture2D(samplers[index], vec2(coords.x - 1.0 * blurX, coords.y - 1.0 * blurY)) * 0.1945945946;
sum += texture2D(samplers[index], vec2(coords.x, coords.y)) * 0.2270270270;
sum += texture2D(samplers[index], vec2(coords.x + 1.0 * blurX, coords.y + 1.0 * blurY)) * 0.1945945946;
sum += texture2D(samplers[index], vec2(coords.x + 2.0 * blurX, coords.y + 2.0 * blurY)) * 0.1216216216;
sum += texture2D(samplers[index], vec2(coords.x + 3.0 * blurX, coords.y + 3.0 * blurY)) * 0.0540540541;
sum += texture2D(samplers[index], vec2(coords.x + 4.0 * blurX, coords.y + 4.0 * blurY)) * 0.0162162162;
fragColor = color * vec4(sum.rgb, 1.0);
}
This is how I render the FrameBuffer:
public void render(boolean fixed) {
model.setTextureID(Shader.getTextureID(texture));
model.buffer(vertices);
indices.put(0).put(1).put(2).put(2).put(3).put(0);
vertices.flip();
indices.flip();
shader.bind();
texture.bind();
shader.setUniform1iv("samplers", Shader.SAMPLERS);
shader.setUniform1f("radius", 10.0f);
shader.setUniform2f("resolution", width, height);
shader.setUniform2f("direction", horizontal, vertical);
if(fixed) {
shader.setUniformMatrix4f("camProjection", Camera.fixedProjection);
shader.setUniformMatrix4f("camTranslation", Camera.fixedTranslation);
} else {
shader.setUniformMatrix4f("camProjection", Camera.projection);
shader.setUniformMatrix4f("camTranslation", Camera.translation);
}
vao.bind();
vbo.bind();
vbo.uploadSubData(0, vertices);
ibo.bind();
ibo.uploadSubData(0, indices);
GL11.glDrawElements(GL11.GL_TRIANGLES, Model.INDICES, GL11.GL_UNSIGNED_INT, 0);
vao.unbind();
texture.unbind();
shader.unbind();
vertices.clear();
indices.clear();
}
The sampler uniform works perfectly fine though, the problem only seems to affect the other three uniforms.
I don't have much experience with OpenGL and GLSL, what am I missing?
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