134 lines
3.8 KiB
Java
134 lines
3.8 KiB
Java
package io.github.hydos.ginger.engine.shadow;
|
|
|
|
import java.nio.ByteBuffer;
|
|
|
|
import org.lwjgl.opengl.GL11;
|
|
import org.lwjgl.opengl.GL12;
|
|
import org.lwjgl.opengl.GL14;
|
|
import org.lwjgl.opengl.GL30;
|
|
import org.lwjgl.opengl.GL32;
|
|
|
|
import io.github.hydos.ginger.engine.io.Window;
|
|
|
|
/**
|
|
* The frame buffer for the shadow pass. This class sets up the depth texture
|
|
* which can be rendered to during the shadow render pass, producing a shadow
|
|
* map.
|
|
*
|
|
*
|
|
*/
|
|
public class ShadowFrameBuffer {
|
|
|
|
private final int WIDTH;
|
|
private final int HEIGHT;
|
|
private int fbo;
|
|
private int shadowMap;
|
|
|
|
/**
|
|
* Initialises the frame buffer and shadow map of a certain size.
|
|
*
|
|
* @param width
|
|
* - the width of the shadow map in pixels.
|
|
* @param height
|
|
* - the height of the shadow map in pixels.
|
|
*/
|
|
protected ShadowFrameBuffer(int width, int height) {
|
|
this.WIDTH = width;
|
|
this.HEIGHT = height;
|
|
initialiseFrameBuffer();
|
|
}
|
|
|
|
/**
|
|
* Deletes the frame buffer and shadow map texture when the game closes.
|
|
*/
|
|
protected void cleanUp() {
|
|
GL30.glDeleteFramebuffers(fbo);
|
|
GL11.glDeleteTextures(shadowMap);
|
|
}
|
|
|
|
/**
|
|
* Binds the frame buffer, setting it as the current render target.
|
|
*/
|
|
protected void bindFrameBuffer() {
|
|
bindFrameBuffer(fbo, WIDTH, HEIGHT);
|
|
}
|
|
|
|
/**
|
|
* Unbinds the frame buffer, setting the default frame buffer as the current
|
|
* render target.
|
|
*/
|
|
protected void unbindFrameBuffer() {
|
|
GL30.glBindFramebuffer(GL30.GL_FRAMEBUFFER, 0);
|
|
GL11.glViewport(0, 0, Window.width, Window.height);
|
|
}
|
|
|
|
/**
|
|
* @return The ID of the shadow map texture.
|
|
*/
|
|
protected int getShadowMap() {
|
|
return shadowMap;
|
|
}
|
|
|
|
/**
|
|
* Creates the frame buffer and adds its depth attachment texture.
|
|
*/
|
|
private void initialiseFrameBuffer() {
|
|
fbo = createFrameBuffer();
|
|
shadowMap = createDepthBufferAttachment(WIDTH, HEIGHT);
|
|
unbindFrameBuffer();
|
|
}
|
|
|
|
/**
|
|
* Binds the frame buffer as the current render target.
|
|
*
|
|
* @param frameBuffer
|
|
* - the frame buffer.
|
|
* @param width
|
|
* - the width of the frame buffer.
|
|
* @param height
|
|
* - the height of the frame buffer.
|
|
*/
|
|
private static void bindFrameBuffer(int frameBuffer, int width, int height) {
|
|
GL11.glBindTexture(GL11.GL_TEXTURE_2D, 0);
|
|
GL30.glBindFramebuffer(GL30.GL_DRAW_FRAMEBUFFER, frameBuffer);
|
|
GL11.glViewport(0, 0, width, height);
|
|
}
|
|
|
|
/**
|
|
* Creates a frame buffer and binds it so that attachments can be added to
|
|
* it. The draw buffer is set to none, indicating that there's no colour
|
|
* buffer to be rendered to.
|
|
*
|
|
* @return The newly created frame buffer's ID.
|
|
*/
|
|
private static int createFrameBuffer() {
|
|
int frameBuffer = GL30.glGenFramebuffers();
|
|
GL30.glBindFramebuffer(GL30.GL_FRAMEBUFFER, frameBuffer);
|
|
GL11.glDrawBuffer(GL11.GL_NONE);
|
|
GL11.glReadBuffer(GL11.GL_NONE);
|
|
return frameBuffer;
|
|
}
|
|
|
|
/**
|
|
* Creates a depth buffer texture attachment.
|
|
*
|
|
* @param width
|
|
* - the width of the texture.
|
|
* @param height
|
|
* - the height of the texture.
|
|
* @return The ID of the depth texture.
|
|
*/
|
|
private static int createDepthBufferAttachment(int width, int height) {
|
|
int texture = GL11.glGenTextures();
|
|
GL11.glBindTexture(GL11.GL_TEXTURE_2D, texture);
|
|
GL11.glTexImage2D(GL11.GL_TEXTURE_2D, 0, GL14.GL_DEPTH_COMPONENT16, width, height, 0,
|
|
GL11.GL_DEPTH_COMPONENT, GL11.GL_FLOAT, (ByteBuffer) null);
|
|
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MAG_FILTER, GL11.GL_NEAREST);
|
|
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_MIN_FILTER, GL11.GL_NEAREST);
|
|
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_S, GL12.GL_CLAMP_TO_EDGE);
|
|
GL11.glTexParameteri(GL11.GL_TEXTURE_2D, GL11.GL_TEXTURE_WRAP_T, GL12.GL_CLAMP_TO_EDGE);
|
|
GL32.glFramebufferTexture(GL30.GL_FRAMEBUFFER, GL30.GL_DEPTH_ATTACHMENT, texture, 0);
|
|
return texture;
|
|
}
|
|
}
|