From 322677b8789c031024fb3fb4618f27e7a6ffec5d Mon Sep 17 00:00:00 2001
From: Nicolai Haehnle <nhaehnle@gmail.com>
Date: Sun, 27 Jul 2008 18:18:59 +0200
Subject: r300: Implement hardware acceleration for ColorLogicOp

---
 src/mesa/drivers/dri/r300/r300_state.c | 44 +++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

(limited to 'src/mesa/drivers/dri/r300/r300_state.c')

diff --git a/src/mesa/drivers/dri/r300/r300_state.c b/src/mesa/drivers/dri/r300/r300_state.c
index 6931de4421..ec17974d78 100644
--- a/src/mesa/drivers/dri/r300/r300_state.c
+++ b/src/mesa/drivers/dri/r300/r300_state.c
@@ -321,6 +321,44 @@ static void r300BlendFuncSeparate(GLcontext * ctx,
 	r300SetBlendState(ctx);
 }
 
+/**
+ * Translate LogicOp enums into hardware representation.
+ * Both use a very logical bit-wise layout, but unfortunately the order
+ * of bits is reversed.
+ */
+static GLuint translate_logicop(GLenum logicop)
+{
+	GLuint bits = logicop - GL_CLEAR;
+	bits = ((bits & 1) << 3) | ((bits & 2) << 1) | ((bits & 4) >> 1) | ((bits & 8) >> 3);
+	return bits << R300_RB3D_ROPCNTL_ROP_SHIFT;
+}
+
+/**
+ * Used internally to update the r300->hw hardware state to match the
+ * current OpenGL state.
+ */
+static void r300SetLogicOpState(GLcontext *ctx)
+{
+	r300ContextPtr r300 = R300_CONTEXT(ctx);
+	R300_STATECHANGE(r300, rop);
+	if (RGBA_LOGICOP_ENABLED(ctx)) {
+		r300->hw.rop.cmd[1] = R300_RB3D_ROPCNTL_ROP_ENABLE |
+			translate_logicop(ctx->Color.LogicOp);
+	} else {
+		r300->hw.rop.cmd[1] = 0;
+	}
+}
+
+/**
+ * Called by Mesa when an application program changes the LogicOp state
+ * via glLogicOp.
+ */
+static void r300LogicOpcode(GLcontext *ctx, GLenum logicop)
+{
+	if (RGBA_LOGICOP_ENABLED(ctx))
+		r300SetLogicOpState(ctx);
+}
+
 static void r300ClipPlane( GLcontext *ctx, GLenum plane, const GLfloat *eq )
 {
 	r300ContextPtr rmesa = R300_CONTEXT(ctx);
@@ -2117,8 +2155,10 @@ static void r300Enable(GLcontext * ctx, GLenum cap, GLboolean state)
 	case GL_ALPHA_TEST:
 		r300SetAlphaState(ctx);
 		break;
-	case GL_BLEND:
 	case GL_COLOR_LOGIC_OP:
+		r300SetLogicOpState(ctx);
+		/* fall-through, because logic op overrides blending */
+	case GL_BLEND:
 		r300SetBlendState(ctx);
 		break;
 	case GL_CLIP_PLANE0:
@@ -2188,6 +2228,7 @@ static void r300ResetHwState(r300ContextPtr r300)
 	r300UpdateTextureState(ctx);
 
 	r300SetBlendState(ctx);
+	r300SetLogicOpState(ctx);
 
 	r300AlphaFunc(ctx, ctx->Color.AlphaFunc, ctx->Color.AlphaRef);
 	r300Enable(ctx, GL_ALPHA_TEST, ctx->Color.AlphaEnabled);
@@ -2755,6 +2796,7 @@ void r300InitStateFuncs(struct dd_function_table *functions)
 	functions->Fogfv = r300Fogfv;
 	functions->FrontFace = r300FrontFace;
 	functions->ShadeModel = r300ShadeModel;
+	functions->LogicOpcode = r300LogicOpcode;
 
 	/* ARB_point_parameters */
 	functions->PointParameterfv = r300PointParameter;
-- 
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