#include "framebuffer.h"
#include "main/blend.h"
+#include "main/glformats.h"
#include "main/macros.h"
/**
* Figure out if colormasks are different per rt.
*/
static GLboolean
-colormask_per_rt(const struct gl_context *ctx)
+colormask_per_rt(const struct gl_context *ctx, unsigned num_cb)
{
+ GLbitfield full_mask = _mesa_replicate_colormask(0xf, num_cb);
GLbitfield repl_mask0 =
_mesa_replicate_colormask(GET_COLORMASK(ctx->Color.ColorMask, 0),
- ctx->Const.MaxDrawBuffers);
+ num_cb);
- return ctx->Color.ColorMask != repl_mask0;
+ return (ctx->Color.ColorMask & full_mask) != repl_mask0;
}
/**
* Figure out if blend enables/state are different per rt.
*/
static GLboolean
-blend_per_rt(const struct gl_context *ctx)
+blend_per_rt(const struct st_context *st, unsigned num_cb)
{
- if (ctx->Color.BlendEnabled &&
- (ctx->Color.BlendEnabled != ((1U << ctx->Const.MaxDrawBuffers) - 1))) {
+ const struct gl_context *ctx = st->ctx;
+ GLbitfield cb_mask = u_bit_consecutive(0, num_cb);
+ GLbitfield blend_enabled = ctx->Color.BlendEnabled & cb_mask;
+
+ if (blend_enabled && blend_enabled != cb_mask) {
/* This can only happen if GL_EXT_draw_buffers2 is enabled */
return GL_TRUE;
}
/* this can only happen if GL_ARB_draw_buffers_blend is enabled */
return GL_TRUE;
}
+ if (ctx->DrawBuffer->_IntegerBuffers &&
+ (ctx->DrawBuffer->_IntegerBuffers != cb_mask)) {
+ /* If there is a mix of integer/non-integer buffers then blending
+ * must be handled on a per buffer basis. */
+ return GL_TRUE;
+ }
+
+ if (st->needs_rgb_dst_alpha_override && ctx->DrawBuffer->_RGBBuffers) {
+ /* Overriding requires independent blend functions (not just enables),
+ * require drivers exposing PIPE_CAP_RGB_OVERRIDE_DST_ALPHA_BLEND to
+ * also expose PIPE_CAP_INDEP_BLEND_FUNC.
+ */
+ assert(st->has_indep_blend_func);
+
+ /* If some of the buffers are RGB, we may need to override blend
+ * factors that reference destination-alpha to constants. We may
+ * need different blend factor overrides per buffer (say one uses
+ * a DST_ALPHA factor and another uses INV_DST_ALPHA), so we flip
+ * on independent blending. This may not be required in all cases,
+ * but burning the CPU to figure it out is probably not worthwhile.
+ */
+ return GL_TRUE;
+ }
+
return GL_FALSE;
}
+/**
+ * Modify blend function to force destination alpha to 1.0
+ *
+ * If \c function specifies a blend function that uses destination alpha,
+ * replace it with a function that hard-wires destination alpha to 1.0.
+ * This is useful when emulating a GL RGB format with an RGBA pipe_format.
+ */
+static enum pipe_blendfactor
+fix_xrgb_alpha(enum pipe_blendfactor factor)
+{
+ switch (factor) {
+ case PIPE_BLENDFACTOR_DST_ALPHA:
+ return PIPE_BLENDFACTOR_ONE;
+
+ case PIPE_BLENDFACTOR_INV_DST_ALPHA:
+ case PIPE_BLENDFACTOR_SRC_ALPHA_SATURATE:
+ return PIPE_BLENDFACTOR_ZERO;
+ default:
+ return factor;
+ }
+}
+
void
st_update_blend( struct st_context *st )
{
struct pipe_blend_state *blend = &st->state.blend;
const struct gl_context *ctx = st->ctx;
+ unsigned num_cb = st->state.fb_num_cb;
unsigned num_state = 1;
unsigned i, j;
memset(blend, 0, sizeof(*blend));
- if (blend_per_rt(ctx) || colormask_per_rt(ctx)) {
- num_state = ctx->Const.MaxDrawBuffers;
+ if (num_cb > 1 &&
+ (blend_per_rt(st, num_cb) || colormask_per_rt(ctx, num_cb))) {
+ num_state = num_cb;
blend->independent_blend_enable = 1;
}
/* blending enabled */
for (i = 0, j = 0; i < num_state; i++) {
if (!(ctx->Color.BlendEnabled & (1 << i)) ||
+ (ctx->DrawBuffer->_IntegerBuffers & (1 << i)) ||
!blend->rt[i].colormask)
continue;
- if (ctx->Extensions.ARB_draw_buffers_blend)
+ if (ctx->Extensions.ARB_draw_buffers_blend)
j = i;
blend->rt[i].blend_enable = 1;
blend->rt[i].alpha_dst_factor =
translate_blend(ctx->Color.Blend[j].DstA);
}
+
+ const struct gl_renderbuffer *rb =
+ ctx->DrawBuffer->_ColorDrawBuffers[i];
+
+ if (st->needs_rgb_dst_alpha_override && rb &&
+ (ctx->DrawBuffer->_RGBBuffers & (1 << i))) {
+ struct pipe_rt_blend_state *rt = &blend->rt[i];
+ rt->rgb_src_factor = fix_xrgb_alpha(rt->rgb_src_factor);
+ rt->rgb_dst_factor = fix_xrgb_alpha(rt->rgb_dst_factor);
+ rt->alpha_src_factor = fix_xrgb_alpha(rt->alpha_src_factor);
+ rt->alpha_dst_factor = fix_xrgb_alpha(rt->alpha_dst_factor);
+ }
}
}
else {