Simplify ctx->_NumColorDrawBuffers, _ColorDrawBuffers and fix bug 13835.

These fields are no longer indexed by shader output.  Now, we just have
a simple array of renderbuffer pointers.

If the shader writes to gl_FragData[i], send those colors to the N
_ColorDrawBuffers.  Otherwise, replicate the single gl_FragColor (or
the fixed-function color) to the N _ColorDrawBuffers.

A few more changes and simplifications can follow from this...

13 files changed, 40 insertions, 47 deletions

diff --git a/src/mesa/drivers/dri/i915/intel_state.c b/src/mesa/drivers/dri/i915/intel_state.c
index 4bcc9af2b60..d1ca11dec4f 100644
--- a/src/mesa/drivers/dri/i915/intel_state.c
+++ b/src/mesa/drivers/dri/i915/intel_state.c
@@ -234,7 +234,7 @@ intelCalcViewport(GLcontext * ctx)
    if (ctx->DrawBuffer->Name) {
       /* User created FBO */
       struct intel_renderbuffer *irb
-         = intel_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0][0]);
+         = intel_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]);
       if (irb && !irb->RenderToTexture) {
          /* y=0=top */
          yScale = -1.0;
diff --git a/src/mesa/drivers/dri/i965/brw_fallback.c b/src/mesa/drivers/dri/i965/brw_fallback.c
index 3c4c60a3eab..58aeeb4228c 100644
--- a/src/mesa/drivers/dri/i965/brw_fallback.c
+++ b/src/mesa/drivers/dri/i965/brw_fallback.c
@@ -62,12 +62,9 @@ static GLboolean do_check_fallback(struct brw_context *brw)
    /* We can only handle a single draw buffer at the moment, and only as the
     * first color buffer.
     */
-   for (i = 0; i < MAX_DRAW_BUFFERS; i++) {
-      if (fb->_NumColorDrawBuffers[i] > (i == 0 ? 1 : 0)) {
-	 DBG("FALLBACK: draw buffer %d: 0x%08x\n",
-	     i, ctx->DrawBuffer->_ColorDrawBufferMask[i]);
-	 return GL_TRUE;
-      }
+   if (fb->_NumColorDrawBuffers > 1) {
+      DBG("FALLBACK: multiple color draw buffers\n");
+      return GL_TRUE;
    }
 
    /* _NEW_RENDERMODE
diff --git a/src/mesa/drivers/dri/i965/brw_sf_state.c b/src/mesa/drivers/dri/i965/brw_sf_state.c
index 05c64909495..f083e3148b1 100644
--- a/src/mesa/drivers/dri/i965/brw_sf_state.c
+++ b/src/mesa/drivers/dri/i965/brw_sf_state.c
@@ -43,7 +43,7 @@ static void upload_sf_vp(struct brw_context *brw)
    const GLfloat depth_scale = 1.0F / ctx->DrawBuffer->_DepthMaxF;
    struct brw_sf_viewport sfv;
    struct intel_renderbuffer *irb =
-      intel_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0][0]);
+      intel_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]);
    GLfloat y_scale, y_bias;
 
    memset(&sfv, 0, sizeof(sfv));
diff --git a/src/mesa/drivers/dri/intel/intel_buffers.c b/src/mesa/drivers/dri/intel/intel_buffers.c
index 78ffa3c1f84..c654474200b 100644
--- a/src/mesa/drivers/dri/intel/intel_buffers.c
+++ b/src/mesa/drivers/dri/intel/intel_buffers.c
@@ -102,7 +102,7 @@ struct intel_region *
 intel_drawbuf_region(struct intel_context *intel)
 {
    struct intel_renderbuffer *irbColor =
-      intel_renderbuffer(intel->ctx.DrawBuffer->_ColorDrawBuffers[0][0]);
+      intel_renderbuffer(intel->ctx.DrawBuffer->_ColorDrawBuffers[0]);
    if (irbColor)
       return irbColor->region;
    else
@@ -931,7 +931,7 @@ intel_draw_buffer(GLcontext * ctx, struct gl_framebuffer *fb)
    /*
     * How many color buffers are we drawing into?
     */
-   if (fb->_NumColorDrawBuffers[0] != 1) {
+   if (fb->_NumColorDrawBuffers != 1) {
       /* writing to 0 or 2 or 4 color buffers */
       /*_mesa_debug(ctx, "Software rendering\n");*/
       FALLBACK(intel, INTEL_FALLBACK_DRAW_BUFFER, GL_TRUE);
@@ -967,7 +967,7 @@ intel_draw_buffer(GLcontext * ctx, struct gl_framebuffer *fb)
 	 /* drawing to user-created FBO */
 	 struct intel_renderbuffer *irb;
 	 intelSetRenderbufferClipRects(intel);
-	 irb = intel_renderbuffer(fb->_ColorDrawBuffers[0][0]);
+	 irb = intel_renderbuffer(fb->_ColorDrawBuffers[0]);
 	 colorRegion = (irb && irb->region) ? irb->region : NULL;
       }
    }
diff --git a/src/mesa/drivers/dri/intel/intel_span.c b/src/mesa/drivers/dri/intel/intel_span.c
index 9ce4a184fd4..298e453c428 100644
--- a/src/mesa/drivers/dri/intel/intel_span.c
+++ b/src/mesa/drivers/dri/intel/intel_span.c
@@ -186,21 +186,18 @@ intel_map_unmap_buffers(struct intel_context *intel, GLboolean map)
    struct intel_renderbuffer *irb;
 
    /* color draw buffers */
-   for (i = 0; i < ctx->Const.MaxDrawBuffers; i++) {
-      for (j = 0; j < ctx->DrawBuffer->_NumColorDrawBuffers[i]; j++) {
-         struct gl_renderbuffer *rb =
-            ctx->DrawBuffer->_ColorDrawBuffers[i][j];
-         irb = intel_renderbuffer(rb);
-         if (irb) {
-            /* this is a user-created intel_renderbuffer */
-            if (irb->region) {
-               if (map)
-                  intel_region_map(intel, irb->region);
-               else
-                  intel_region_unmap(intel, irb->region);
-               irb->pfMap = irb->region->map;
-               irb->pfPitch = irb->region->pitch;
-            }
+   for (j = 0; j < ctx->DrawBuffer->_NumColorDrawBuffers; j++) {
+      struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[j];
+      irb = intel_renderbuffer(rb);
+      if (irb) {
+         /* this is a user-created intel_renderbuffer */
+         if (irb->region) {
+            if (map)
+               intel_region_map(intel, irb->region);
+            else
+               intel_region_unmap(intel, irb->region);
+            irb->pfMap = irb->region->map;
+            irb->pfPitch = irb->region->pitch;
          }
       }
    }
diff --git a/src/mesa/drivers/dri/nouveau/nouveau_driver.c b/src/mesa/drivers/dri/nouveau/nouveau_driver.c
index 8b76779002b..1135817fe9a 100644
--- a/src/mesa/drivers/dri/nouveau/nouveau_driver.c
+++ b/src/mesa/drivers/dri/nouveau/nouveau_driver.c
@@ -149,12 +149,12 @@ static void nouveauClear( GLcontext *ctx, GLbitfield mask )
 		clear_value = PACK_COLOR_8888(c[3],c[0],c[1],c[2]);
 
 		if (ctx->DrawBuffer) {
-			/* FIXME: find correct color buffer, instead of [0][0] */
-			if (ctx->DrawBuffer->_ColorDrawBuffers[0][0]) {
-				color_bits = ctx->DrawBuffer->_ColorDrawBuffers[0][0]->RedBits;
-				color_bits += ctx->DrawBuffer->_ColorDrawBuffers[0][0]->GreenBits;
-				color_bits += ctx->DrawBuffer->_ColorDrawBuffers[0][0]->BlueBits;
-				color_bits += ctx->DrawBuffer->_ColorDrawBuffers[0][0]->AlphaBits;
+			/* FIXME: find correct color buffer, instead of [0] */
+			if (ctx->DrawBuffer->_ColorDrawBuffers[0]) {
+				color_bits = ctx->DrawBuffer->_ColorDrawBuffers[0]->RedBits;
+				color_bits += ctx->DrawBuffer->_ColorDrawBuffers[0]->GreenBits;
+				color_bits += ctx->DrawBuffer->_ColorDrawBuffers[0]->BlueBits;
+				color_bits += ctx->DrawBuffer->_ColorDrawBuffers[0]->AlphaBits;
 			}
 		}
 
diff --git a/src/mesa/drivers/dri/nouveau/nouveau_fbo.c b/src/mesa/drivers/dri/nouveau/nouveau_fbo.c
index cc3da8b9bde..23525509d14 100644
--- a/src/mesa/drivers/dri/nouveau/nouveau_fbo.c
+++ b/src/mesa/drivers/dri/nouveau/nouveau_fbo.c
@@ -177,8 +177,7 @@ nouveau_window_moved(GLcontext * ctx)
 	nouveauContextPtr nmesa = NOUVEAU_CONTEXT(ctx);
 	nouveau_renderbuffer_t *nrb;
 
-	nrb = (nouveau_renderbuffer_t *)
-		ctx->DrawBuffer->_ColorDrawBuffers[0][0];
+	nrb = (nouveau_renderbuffer_t *) ctx->DrawBuffer->_ColorDrawBuffers[0];
 	if (!nrb)
 		return;
 
@@ -204,7 +203,7 @@ nouveau_build_framebuffer(GLcontext *ctx, struct gl_framebuffer *fb)
 	_mesa_update_framebuffer(ctx);
 	_mesa_update_draw_buffer_bounds(ctx);
 
-	color[0] = (nouveau_renderbuffer_t *) fb->_ColorDrawBuffers[0][0];
+	color[0] = (nouveau_renderbuffer_t *) fb->_ColorDrawBuffers[0];
 	if (fb->_DepthBuffer && fb->_DepthBuffer->Wrapped)
 		depth = (nouveau_renderbuffer_t *) fb->_DepthBuffer->Wrapped;
 	else
diff --git a/src/mesa/drivers/dri/r128/r128_state.c b/src/mesa/drivers/dri/r128/r128_state.c
index e476afa5d82..f1e92d7a7a9 100644
--- a/src/mesa/drivers/dri/r128/r128_state.c
+++ b/src/mesa/drivers/dri/r128/r128_state.c
@@ -813,7 +813,7 @@ static void r128UpdateWindow( GLcontext *ctx )
    r128ContextPtr rmesa = R128_CONTEXT(ctx);
    int x = rmesa->driDrawable->x;
    int y = rmesa->driDrawable->y;
-   struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0][0];
+   struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];
    driRenderbuffer *drb = (driRenderbuffer *) rb;
 
    rmesa->setup.window_xy_offset = (((y & 0xFFF) << R128_WINDOW_Y_SHIFT) |
diff --git a/src/mesa/drivers/dri/r200/r200_pixel.c b/src/mesa/drivers/dri/r200/r200_pixel.c
index 2f5aab0744b..db8ceeabe03 100644
--- a/src/mesa/drivers/dri/r200/r200_pixel.c
+++ b/src/mesa/drivers/dri/r200/r200_pixel.c
@@ -294,7 +294,7 @@ static void do_draw_pix( GLcontext *ctx,
    r200ContextPtr rmesa = R200_CONTEXT(ctx);
    __DRIdrawablePrivate *dPriv = rmesa->dri.drawable;
    drm_clip_rect_t *box = dPriv->pClipRects;
-   struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorDrawBuffers[0][0];
+   struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorDrawBuffers[0];
    driRenderbuffer *drb = (driRenderbuffer *) rb;
    int nbox = dPriv->numClipRects;
    int i;
@@ -388,7 +388,7 @@ r200TryDrawPixels( GLcontext *ctx,
       fprintf(stderr, "%s\n", __FUNCTION__);
 
    /* check that we're drawing to exactly one color buffer */
-   if (ctx->DrawBuffer->_NumColorDrawBuffers[0] != 1)
+   if (ctx->DrawBuffer->_NumColorDrawBuffers != 1)
      return GL_FALSE;
 
    switch (format) {
diff --git a/src/mesa/drivers/dri/r200/r200_span.c b/src/mesa/drivers/dri/r200/r200_span.c
index fe427bdcdec..ff2eb011225 100644
--- a/src/mesa/drivers/dri/r200/r200_span.c
+++ b/src/mesa/drivers/dri/r200/r200_span.c
@@ -255,7 +255,7 @@ static void r200SpanRenderStart( GLcontext *ctx )
    {
       int p;
       driRenderbuffer *drb =
-	 (driRenderbuffer *) ctx->WinSysDrawBuffer->_ColorDrawBuffers[0][0];
+	 (driRenderbuffer *) ctx->WinSysDrawBuffer->_ColorDrawBuffers[0];
       volatile int *buf =
 	 (volatile int *)(rmesa->dri.screen->pFB + drb->offset);
       p = *buf;
diff --git a/src/mesa/drivers/x11/xm_dd.c b/src/mesa/drivers/x11/xm_dd.c
index 4c8bf5f656d..e7d41401f9a 100644
--- a/src/mesa/drivers/x11/xm_dd.c
+++ b/src/mesa/drivers/x11/xm_dd.c
@@ -435,7 +435,7 @@ xmesa_DrawPixels_8R8G8B( GLcontext *ctx,
                          const GLvoid *pixels )
 {
    const SWcontext *swrast = SWRAST_CONTEXT( ctx );
-   struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0][0];
+   struct gl_renderbuffer *rb = ctx->DrawBuffer->_ColorDrawBuffers[0];
    struct xmesa_renderbuffer *xrb = xmesa_renderbuffer(rb->Wrapped);
 
    if (swrast->NewState)
@@ -544,7 +544,7 @@ xmesa_DrawPixels_5R6G5B( GLcontext *ctx,
                          const GLvoid *pixels )
 {
    struct xmesa_renderbuffer *xrb
-      = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0][0]->Wrapped);
+      = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]->Wrapped);
    const XMesaContext xmesa = XMESA_CONTEXT(ctx);
    const SWcontext *swrast = SWRAST_CONTEXT( ctx );
    XMesaDisplay *dpy = xmesa->xm_visual->display;
@@ -654,7 +654,7 @@ xmesa_CopyPixels( GLcontext *ctx,
    struct xmesa_renderbuffer *srcXrb
       = xmesa_renderbuffer(ctx->ReadBuffer->_ColorReadBuffer->Wrapped);
    struct xmesa_renderbuffer *dstXrb
-      = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0][0]->Wrapped);
+      = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]->Wrapped);
 
    ASSERT(dpy);
    ASSERT(gc);
diff --git a/src/mesa/drivers/x11/xm_line.c b/src/mesa/drivers/x11/xm_line.c
index deeae5019c4..7109c439157 100644
--- a/src/mesa/drivers/x11/xm_line.c
+++ b/src/mesa/drivers/x11/xm_line.c
@@ -121,7 +121,7 @@ void xmesa_choose_point( GLcontext *ctx )
 
 
 #define GET_XRB(XRB)  struct xmesa_renderbuffer *XRB = \
-   xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0][0]->Wrapped)
+   xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]->Wrapped)
 
 
 /*
@@ -598,7 +598,7 @@ get_line_func(GLcontext *ctx)
    if (swrast->_RasterMask & MULTI_DRAW_BIT) return (swrast_line_func) NULL;
    if (xmbuf->swAlpha)                    return (swrast_line_func) NULL;
 
-   xrb = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0][0]->Wrapped);
+   xrb = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]->Wrapped);
 
    if (xrb->ximage
        && swrast->_RasterMask==DEPTH_BIT
@@ -661,7 +661,7 @@ get_line_func(GLcontext *ctx)
    }
 
 #ifndef XFree86Server
-   if (ctx->DrawBuffer->_NumColorDrawBuffers[0] == 1
+   if (ctx->DrawBuffer->_NumColorDrawBuffers == 1
        && ctx->DrawBuffer->_ColorDrawBufferMask[0] == BUFFER_BIT_FRONT_LEFT
        && swrast->_RasterMask == LOGIC_OP_BIT
        && ctx->Color.LogicOp == GL_XOR
diff --git a/src/mesa/drivers/x11/xm_tri.c b/src/mesa/drivers/x11/xm_tri.c
index 95c6d7c1d20..a3978abdd07 100644
--- a/src/mesa/drivers/x11/xm_tri.c
+++ b/src/mesa/drivers/x11/xm_tri.c
@@ -45,7 +45,7 @@
 
 
 #define GET_XRB(XRB)  struct xmesa_renderbuffer *XRB = \
-   xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0][0]->Wrapped)
+   xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]->Wrapped)
 
 
 /**********************************************************************/
@@ -1479,7 +1479,7 @@ get_triangle_func(GLcontext *ctx)
    if (xmbuf->swAlpha)
       return (swrast_tri_func) NULL;
 
-   xrb = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0][0]->Wrapped);
+   xrb = xmesa_renderbuffer(ctx->DrawBuffer->_ColorDrawBuffers[0]->Wrapped);
 
    if (xrb->ximage) {
       if (   ctx->Light.ShadeModel==GL_SMOOTH