Move Intel MDI workaround to GlCompat

Engine-Room · Jul 15, 2024 · 4e8dcb0 · 4e8dcb0
1 parent b2483de
commit 4e8dcb0
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Showing 2 changed files with 20 additions and 11 deletions.
diff --git a/...c/backend/java/dev/engine_room/flywheel/backend/engine/indirect/IndirectCullingGroup.java b/...c/backend/java/dev/engine_room/flywheel/backend/engine/indirect/IndirectCullingGroup.java
@@ -3,12 +3,10 @@
 import static org.lwjgl.opengl.GL11.GL_TRIANGLES;
 import static org.lwjgl.opengl.GL11.GL_UNSIGNED_INT;
 import static org.lwjgl.opengl.GL30.glUniform1ui;
-import static org.lwjgl.opengl.GL40.glDrawElementsIndirect;
 import static org.lwjgl.opengl.GL42.GL_COMMAND_BARRIER_BIT;
 import static org.lwjgl.opengl.GL42.glMemoryBarrier;
 import static org.lwjgl.opengl.GL43.GL_SHADER_STORAGE_BARRIER_BIT;
 import static org.lwjgl.opengl.GL43.glDispatchCompute;
-import static org.lwjgl.opengl.GL43.glMultiDrawElementsIndirect;
 
 import java.util.ArrayList;
 import java.util.Comparator;
@@ -27,7 +25,6 @@
 import dev.engine_room.flywheel.backend.engine.MeshPool;
 import dev.engine_room.flywheel.backend.engine.embed.Environment;
 import dev.engine_room.flywheel.backend.engine.uniform.Uniforms;
-import dev.engine_room.flywheel.backend.gl.Driver;
 import dev.engine_room.flywheel.backend.gl.GlCompat;
 import dev.engine_room.flywheel.backend.gl.shader.GlProgram;
 import dev.engine_room.flywheel.lib.math.MoreMath;
@@ -282,14 +279,7 @@ public void delete() {
 
 	private record MultiDraw(Material material, int start, int end) {
 		private void submit() {
-			if (GlCompat.DRIVER == Driver.INTEL) {
-				// Intel renders garbage with MDI, but Consecutive Normal Draws works fine.
-				for (int i = this.start; i < this.end; i++) {
-					glDrawElementsIndirect(GL_TRIANGLES, GL_UNSIGNED_INT, i * IndirectBuffers.DRAW_COMMAND_STRIDE);
-				}
-			} else {
-				glMultiDrawElementsIndirect(GL_TRIANGLES, GL_UNSIGNED_INT, this.start * IndirectBuffers.DRAW_COMMAND_STRIDE, this.end - this.start, (int) IndirectBuffers.DRAW_COMMAND_STRIDE);
-			}
+			GlCompat.safeMultiDrawElementsIndirect(GL_TRIANGLES, GL_UNSIGNED_INT, this.start * IndirectBuffers.DRAW_COMMAND_STRIDE, this.end - this.start, (int) IndirectBuffers.DRAW_COMMAND_STRIDE);
 		}
 	}
 }
diff --git a/common/src/backend/java/dev/engine_room/flywheel/backend/gl/GlCompat.java b/common/src/backend/java/dev/engine_room/flywheel/backend/gl/GlCompat.java
@@ -8,6 +8,8 @@
 import org.lwjgl.opengl.GL20;
 import org.lwjgl.opengl.GL20C;
 import org.lwjgl.opengl.GL31C;
+import org.lwjgl.opengl.GL40;
+import org.lwjgl.opengl.GL43;
 import org.lwjgl.opengl.GLCapabilities;
 import org.lwjgl.opengl.KHRShaderSubgroup;
 import org.lwjgl.system.MemoryStack;
@@ -71,6 +73,23 @@ public static void safeShaderSource(int glId, CharSequence source) {
 		}
 	}
 
+	/**
+	 * Similar in function to {@link GL43#glMultiDrawElementsIndirect(int, int, long, int, int)},
+	 * but uses consecutive DI instead of MDI if MDI is known to not work well with the current driver.
+	 * Unlike the original function, stride cannot be equal to 0.
+	 */
+	public static void safeMultiDrawElementsIndirect(int mode, int type, long indirect, int drawcount, int stride) {
+		if (GlCompat.DRIVER == Driver.INTEL) {
+			// Intel renders garbage with MDI, but consecutive DI works fine.
+			for (int i = 0; i < drawcount; i++) {
+				GL40.glDrawElementsIndirect(mode, type, indirect);
+				indirect += stride;
+			}
+		} else {
+			GL43.glMultiDrawElementsIndirect(mode, type, indirect, drawcount, stride);
+		}
+	}
+
 	private static Driver readVendorString() {
 		if (CAPABILITIES == null) {
 			return Driver.UNKNOWN;