llvmpipe/linear: add support for rgba color buffers.

This adds support to the linear rast for rgba outputs.

Reviewed-by: Brian Paul <brianp@vmware.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24066>

src/gallium/drivers/llvmpipe/lp_linear.c

@@ -122,15 +122,19 @@ lp_fs_linear_run(const struct lp_rast_state *state,
    struct lp_jit_linear_context jit;
    jit.constants = (const uint8_t (*)[4])constants;
 
-   /* We assume BGRA ordering */
-   assert(variant->key.cbuf_format[0] == PIPE_FORMAT_B8G8R8X8_UNORM ||
-          variant->key.cbuf_format[0] == PIPE_FORMAT_B8G8R8A8_UNORM);
-
-   jit.blend_color =
+   if (!rgba_order) {
+      jit.blend_color =
          state->jit_context.u8_blend_color[32] +
          (state->jit_context.u8_blend_color[16] << 8) +
          (state->jit_context.u8_blend_color[0] << 16) +
          (state->jit_context.u8_blend_color[48] << 24);
+   } else {
+      jit.blend_color =
+         (state->jit_context.u8_blend_color[32] << 24) +
+         (state->jit_context.u8_blend_color[16] << 16) +
+         (state->jit_context.u8_blend_color[0] << 8) +
+         (state->jit_context.u8_blend_color[48] << 0);
+   }
 
    jit.alpha_ref_value = float_to_ubyte(state->jit_context.alpha_ref_value);
 

src/gallium/drivers/llvmpipe/lp_state_derived.c

@@ -186,18 +186,20 @@ compute_vertex_info(struct llvmpipe_context *llvmpipe)
 static void
 check_linear_rasterizer(struct llvmpipe_context *lp)
 {
-   const bool bgr8 =
+   const bool valid_cb_format =
       (lp->framebuffer.nr_cbufs == 1 && lp->framebuffer.cbufs[0] &&
        util_res_sample_count(lp->framebuffer.cbufs[0]->texture) == 1 &&
        lp->framebuffer.cbufs[0]->texture->target == PIPE_TEXTURE_2D &&
        (lp->framebuffer.cbufs[0]->format == PIPE_FORMAT_B8G8R8A8_UNORM ||
-        lp->framebuffer.cbufs[0]->format == PIPE_FORMAT_B8G8R8X8_UNORM));
+        lp->framebuffer.cbufs[0]->format == PIPE_FORMAT_B8G8R8X8_UNORM ||
+        lp->framebuffer.cbufs[0]->format == PIPE_FORMAT_R8G8B8A8_UNORM ||
+        lp->framebuffer.cbufs[0]->format == PIPE_FORMAT_R8G8B8X8_UNORM));
 
    /* permit_linear means guardband, hence fake scissor, which we can only
     * handle if there's just one vp. */
    const bool single_vp = lp->viewport_index_slot < 0;
    const bool permit_linear = (!lp->framebuffer.zsbuf &&
-                               bgr8 &&
+                               valid_cb_format &&
                                single_vp);
 
    /* Tell draw that we're happy doing our own x/y clipping.

src/gallium/drivers/llvmpipe/lp_state_fs.c

@@ -3863,7 +3863,9 @@ generate_variant(struct llvmpipe_context *lp,
          !shader->info.base.uses_kill &&
          !key->blend.logicop_enable &&
          (key->cbuf_format[0] == PIPE_FORMAT_B8G8R8A8_UNORM ||
-          key->cbuf_format[0] == PIPE_FORMAT_B8G8R8X8_UNORM);
+          key->cbuf_format[0] == PIPE_FORMAT_B8G8R8X8_UNORM ||
+          key->cbuf_format[0] == PIPE_FORMAT_R8G8B8A8_UNORM ||
+          key->cbuf_format[0] == PIPE_FORMAT_R8G8B8X8_UNORM);
 
    memcpy(&variant->key, key, sizeof *key);
 

src/gallium/drivers/llvmpipe/lp_state_fs_linear_llvm.c

@@ -137,11 +137,14 @@ llvm_fragment_body(struct lp_build_context *bld,
                    LLVMValueRef dst)
 {
    static const unsigned char bgra_swizzles[4] = {2, 1, 0, 3};
+   static const unsigned char rgba_swizzles[4] = {0, 1, 2, 3};
    LLVMValueRef inputs[PIPE_MAX_SHADER_INPUTS];
    LLVMValueRef outputs[PIPE_MAX_SHADER_OUTPUTS];
    LLVMBuilderRef builder = bld->gallivm->builder;
    struct gallivm_state *gallivm = bld->gallivm;
    LLVMValueRef result = NULL;
+   bool rgba_order = (variant->key.cbuf_format[0] == PIPE_FORMAT_R8G8B8A8_UNORM ||
+                      variant->key.cbuf_format[0] == PIPE_FORMAT_R8G8B8X8_UNORM);
 
    sampler->instance = 0;
 
@@ -164,14 +167,14 @@ llvm_fragment_body(struct lp_build_context *bld,
 
    if (shader->base.type == PIPE_SHADER_IR_TGSI) {
       lp_build_tgsi_aos(gallivm, shader->base.tokens, fs_type,
-                        bgra_swizzles,
+                        rgba_order ? rgba_swizzles : bgra_swizzles,
                         consts_ptr, inputs, outputs,
                         &sampler->base,
                         &shader->info.base);
    } else {
       nir_shader *clone = nir_shader_clone(NULL, shader->base.ir.nir);
       lp_build_nir_aos(gallivm, clone, fs_type,
-                       bgra_swizzles,
+                       rgba_order ? rgba_swizzles : bgra_swizzles,
                        consts_ptr, inputs, outputs,
                        &sampler->base,
                        &shader->info.base);
@@ -226,7 +229,7 @@ llvm_fragment_body(struct lp_build_context *bld,
                                   mask,
                                   blend_color,  /* const_ */
                                   NULL,         /* const_alpha */
-                                  bgra_swizzles,
+                                  rgba_order ? rgba_swizzles : bgra_swizzles,
                                   4);
    }