st/vega: Add CLEAR renderer state for vgClear.

This state provides the ability to clear rectangles of the framebuffer
to the specified color, honoring scissoring.  vegaClear is updated to
make use of the state.

3 files changed, 68 insertions, 113 deletions

diff --git a/src/gallium/state_trackers/vega/api_masks.c b/src/gallium/state_trackers/vega/api_masks.c
index 189390ec2d..45f77d7d70 100644
--- a/src/gallium/state_trackers/vega/api_masks.c
+++ b/src/gallium/state_trackers/vega/api_masks.c
@@ -28,6 +28,7 @@
 
 #include "mask.h"
 #include "api.h"
+#include "renderer.h"
 
 #include "vg_context.h"
 #include "pipe/p_context.h"
@@ -38,117 +39,6 @@
 
 #define DISABLE_1_1_MASKING 1
 
-/**
- * Draw a screen-aligned quadrilateral.
- * Coords are window coords with y=0=bottom.  These coords will be transformed
- * by the vertex shader and viewport transform.
- */
-static void
-draw_clear_quad(struct vg_context *st,
-                float x0, float y0, float x1, float y1, float z,
-                const VGfloat color[4])
-{
-   struct pipe_context *pipe = st->pipe;
-   struct pipe_resource *buf;
-   VGuint i;
-
-   /* positions */
-   st->clear.vertices[0][0][0] = x0;
-   st->clear.vertices[0][0][1] = y0;
-
-   st->clear.vertices[1][0][0] = x1;
-   st->clear.vertices[1][0][1] = y0;
-
-   st->clear.vertices[2][0][0] = x1;
-   st->clear.vertices[2][0][1] = y1;
-
-   st->clear.vertices[3][0][0] = x0;
-   st->clear.vertices[3][0][1] = y1;
-
-   /* same for all verts: */
-   for (i = 0; i < 4; i++) {
-      st->clear.vertices[i][0][2] = z;
-      st->clear.vertices[i][0][3] = 1.0;
-      st->clear.vertices[i][1][0] = color[0];
-      st->clear.vertices[i][1][1] = color[1];
-      st->clear.vertices[i][1][2] = color[2];
-      st->clear.vertices[i][1][3] = color[3];
-   }
-
-
-   /* put vertex data into vbuf */
-   buf =  pipe_user_buffer_create(pipe->screen,
-                                  st->clear.vertices,
-                                  sizeof(st->clear.vertices),
-				  PIPE_BIND_VERTEX_BUFFER);
-
-
-   /* draw */
-   if (buf) {
-      cso_set_vertex_elements(st->cso_context, 2, st->velems);
-
-      util_draw_vertex_buffer(pipe, buf, 0,
-                              PIPE_PRIM_TRIANGLE_FAN,
-                              4,  /* verts */
-                              2); /* attribs/vert */
-
-      pipe_resource_reference(&buf, NULL);
-   }
-}
-
-/**
- * Do vgClear by drawing a quadrilateral.
- */
-static void
-clear_with_quad(struct vg_context *st, float x0, float y0,
-                float width, float height, const VGfloat clear_color[4])
-{
-   VGfloat x1, y1;
-
-   vg_validate_state(st);
-
-   x1 = x0 + width;
-   y1 = y0 + height;
-
-   /*
-     printf("%s %f,%f %f,%f\n", __FUNCTION__,
-     x0, y0,
-     x1, y1);
-   */
-
-   cso_save_blend(st->cso_context);
-   cso_save_rasterizer(st->cso_context);
-   cso_save_fragment_shader(st->cso_context);
-   cso_save_vertex_shader(st->cso_context);
-
-   /* blend state: RGBA masking */
-   {
-      struct pipe_blend_state blend;
-      memset(&blend, 0, sizeof(blend));
-      blend.rt[0].rgb_src_factor = PIPE_BLENDFACTOR_ONE;
-      blend.rt[0].alpha_src_factor = PIPE_BLENDFACTOR_ONE;
-      blend.rt[0].rgb_dst_factor = PIPE_BLENDFACTOR_ZERO;
-      blend.rt[0].alpha_dst_factor = PIPE_BLENDFACTOR_ZERO;
-      blend.rt[0].colormask = PIPE_MASK_RGBA;
-      cso_set_blend(st->cso_context, &blend);
-   }
-
-   cso_set_rasterizer(st->cso_context, &st->clear.raster);
-
-   cso_set_fragment_shader_handle(st->cso_context, st->clear.fs);
-   cso_set_vertex_shader_handle(st->cso_context, vg_clear_vs(st));
-
-   /* draw quad matching scissor rect (XXX verify coord round-off) */
-   draw_clear_quad(st, x0, y0, x1, y1, 0, clear_color);
-
-   /* Restore pipe state */
-   cso_restore_blend(st->cso_context);
-   cso_restore_rasterizer(st->cso_context);
-   cso_restore_fragment_shader(st->cso_context);
-   cso_restore_vertex_shader(st->cso_context);
-}
-
-
 void vegaMask(VGHandle mask, VGMaskOperation operation,
               VGint x, VGint y,
               VGint width, VGint height)
@@ -214,8 +104,10 @@ void vegaClear(VGint x, VGint y,
        (x == 0 && y == 0 && width == fb->width && height == fb->height)) {
       ctx->pipe->clear(ctx->pipe, PIPE_CLEAR_COLOR | PIPE_CLEAR_DEPTHSTENCIL,
                        ctx->state.vg.clear_color, 1., 0);
-   } else {
-      clear_with_quad(ctx, x, y, width, height, ctx->state.vg.clear_color);
+   } else if (renderer_clear_begin(ctx->renderer)) {
+      /* XXX verify coord round-off */
+      renderer_clear(ctx->renderer, x, y, width, height, ctx->state.vg.clear_color);
+      renderer_clear_end(ctx->renderer);
    }
 }
 
diff --git a/src/gallium/state_trackers/vega/renderer.c b/src/gallium/state_trackers/vega/renderer.c
index 60c4315a1f..d326cfc501 100644
--- a/src/gallium/state_trackers/vega/renderer.c
+++ b/src/gallium/state_trackers/vega/renderer.c
@@ -48,6 +48,7 @@ typedef enum {
    RENDERER_STATE_COPY,
    RENDERER_STATE_DRAWTEX,
    RENDERER_STATE_SCISSOR,
+   RENDERER_STATE_CLEAR,
    NUM_RENDERER_STATES
 } RendererState;
 
@@ -623,6 +624,60 @@ void renderer_scissor_end(struct renderer *renderer)
    renderer->state = RENDERER_STATE_INIT;
 }
 
+/**
+ * Prepare the renderer for clearing.
+ */
+VGboolean renderer_clear_begin(struct renderer *renderer)
+{
+   assert(renderer->state == RENDERER_STATE_INIT);
+
+   cso_save_blend(renderer->cso);
+   cso_save_fragment_shader(renderer->cso);
+   cso_save_vertex_shader(renderer->cso);
+
+   renderer_set_blend(renderer, ~0);
+   renderer_set_fs(renderer, RENDERER_FS_COLOR);
+   renderer_set_vs(renderer, RENDERER_VS_COLOR);
+
+   renderer->state = RENDERER_STATE_CLEAR;
+
+   return VG_TRUE;
+}
+
+/**
+ * Clear the framebuffer with the specified region and color.
+ *
+ * The coordinates are in surface coordinates.
+ */
+void renderer_clear(struct renderer *renderer,
+                    VGint x, VGint y, VGint width, VGint height,
+                    const VGfloat color[4])
+{
+   VGuint i;
+
+   assert(renderer->state == RENDERER_STATE_CLEAR);
+
+   renderer_quad_pos(renderer, x, y, x + width, y + height, VG_TRUE);
+   for (i = 0; i < 4; i++)
+      memcpy(renderer->vertices[i][1], color, sizeof(VGfloat) * 4);
+
+   renderer_quad_draw(renderer);
+}
+
+/**
+ * End clearing and retore the states.
+ */
+void renderer_clear_end(struct renderer *renderer)
+{
+   assert(renderer->state == RENDERER_STATE_CLEAR);
+
+   cso_restore_blend(renderer->cso);
+   cso_restore_fragment_shader(renderer->cso);
+   cso_restore_vertex_shader(renderer->cso);
+
+   renderer->state = RENDERER_STATE_INIT;
+}
+
 static void setup_shaders(struct renderer *ctx)
 {
    struct pipe_context *pipe = ctx->pipe;
diff --git a/src/gallium/state_trackers/vega/renderer.h b/src/gallium/state_trackers/vega/renderer.h
index 2644c9f580..fa0782280a 100644
--- a/src/gallium/state_trackers/vega/renderer.h
+++ b/src/gallium/state_trackers/vega/renderer.h
@@ -68,6 +68,14 @@ void renderer_scissor(struct renderer *renderer,
 
 void renderer_scissor_end(struct renderer *renderer);
 
+VGboolean renderer_clear_begin(struct renderer *renderer);
+
+void renderer_clear(struct renderer *renderer,
+                    VGint x, VGint y, VGint width, VGint height,
+                    const VGfloat color[4]);
+
+void renderer_clear_end(struct renderer *renderer);
+
 void renderer_draw_quad(struct renderer *,
                         VGfloat x1, VGfloat y1,
                         VGfloat x2, VGfloat y2,