gallium: turn on clipping for bitmaps

Bitmaps can extend beyond window edges so we need to clip.
Also, move some state atom vars to st_context to be a bit more efficient.

2 files changed, 60 insertions, 36 deletions

diff --git a/src/mesa/state_tracker/st_cb_bitmap.c b/src/mesa/state_tracker/st_cb_bitmap.c
index ec56b25f7ce..0cc910a67fa 100644
--- a/src/mesa/state_tracker/st_cb_bitmap.c
+++ b/src/mesa/state_tracker/st_cb_bitmap.c
@@ -350,16 +350,21 @@ setup_bitmap_vertex_data(struct st_context *st,
 {
    struct pipe_context *pipe = st->pipe;
    const struct gl_framebuffer *fb = st->ctx->DrawBuffer;
-   const GLboolean invert = (st_fb_orientation(fb) == Y_0_TOP);
+   const GLfloat fb_width = fb->Width;
+   const GLfloat fb_height = fb->Height;
    const GLfloat x0 = x;
    const GLfloat x1 = x + width;
-   const GLfloat y0 = invert ? ((int) fb->Height - y - height) : y;
-   const GLfloat y1 = invert ? (y0 + height) : y + height;
+   const GLfloat y0 = y;
+   const GLfloat y1 = y + height;
    const GLfloat bias = st->bitmap_texcoord_bias;
    const GLfloat xBias = bias / (x1-x0);
    const GLfloat yBias = bias / (y1-y0);
    const GLfloat sLeft = 0.0 + xBias, sRight = 1.0 + xBias;
-   const GLfloat tTop = 1.0 - yBias, tBot = 1.0 - tTop - yBias;
+   const GLfloat tTop = yBias, tBot = 1.0 - tTop - yBias;
+   const GLfloat clip_x0 = x0 / fb_width * 2.0 - 1.0;
+   const GLfloat clip_y0 = y0 / fb_height * 2.0 - 1.0;
+   const GLfloat clip_x1 = x1 / fb_width * 2.0 - 1.0;
+   const GLfloat clip_y1 = y1 / fb_height * 2.0 - 1.0;
    GLuint i;
    void *buf;
 
@@ -369,24 +374,26 @@ setup_bitmap_vertex_data(struct st_context *st,
                                                    sizeof(st->bitmap.vertices));
    }
 
-   /* positions, texcoords */
-   st->bitmap.vertices[0][0][0] = x0;
-   st->bitmap.vertices[0][0][1] = y0;
+   /* Positions are in clip coords since we need to do clipping in case
+    * the bitmap quad goes beyond the window bounds.
+    */
+   st->bitmap.vertices[0][0][0] = clip_x0;
+   st->bitmap.vertices[0][0][1] = clip_y0;
    st->bitmap.vertices[0][2][0] = sLeft;
    st->bitmap.vertices[0][2][1] = tTop;
 
-   st->bitmap.vertices[1][0][0] = x1;
-   st->bitmap.vertices[1][0][1] = y0;
+   st->bitmap.vertices[1][0][0] = clip_x1;
+   st->bitmap.vertices[1][0][1] = clip_y0;
    st->bitmap.vertices[1][2][0] = sRight;
    st->bitmap.vertices[1][2][1] = tTop;
    
-   st->bitmap.vertices[2][0][0] = x1;
-   st->bitmap.vertices[2][0][1] = y1;
+   st->bitmap.vertices[2][0][0] = clip_x1;
+   st->bitmap.vertices[2][0][1] = clip_y1;
    st->bitmap.vertices[2][2][0] = sRight;
    st->bitmap.vertices[2][2][1] = tBot;
    
-   st->bitmap.vertices[3][0][0] = x0;
-   st->bitmap.vertices[3][0][1] = y1;
+   st->bitmap.vertices[3][0][0] = clip_x0;
+   st->bitmap.vertices[3][0][1] = clip_y1;
    st->bitmap.vertices[3][2][0] = sLeft;
    st->bitmap.vertices[3][2][1] = tBot;
    
@@ -437,17 +444,11 @@ draw_bitmap_quad(GLcontext *ctx, GLint x, GLint y, GLfloat z,
 
    cso_save_rasterizer(cso);
    cso_save_samplers(cso);
+   cso_save_viewport(cso);
 
    /* rasterizer state: just scissor */
-   {
-      struct pipe_rasterizer_state rasterizer;
-      memset(&rasterizer, 0, sizeof(rasterizer));
-      if (ctx->Scissor.Enabled)
-         rasterizer.scissor = 1;
-      rasterizer.bypass_clipping = 1;
-
-      cso_set_rasterizer(cso, &rasterizer);
-   }
+   st->bitmap.rasterizer.scissor = ctx->Scissor.Enabled;
+   cso_set_rasterizer(cso, &st->bitmap.rasterizer);
 
    /* fragment shader state: TEX lookup program */
    pipe->bind_fs_state(pipe, stfp->driver_shader);
@@ -456,21 +457,26 @@ draw_bitmap_quad(GLcontext *ctx, GLint x, GLint y, GLfloat z,
    pipe->bind_vs_state(pipe, st->bitmap.vs);
 
    /* sampler / texture state */
+   cso_single_sampler(cso, 0, &st->bitmap.sampler);
+   cso_single_sampler_done(cso);
+   pipe->set_sampler_textures(pipe, 1, &pt);
+
+   /* viewport state: viewport matching window dims */
    {
-      struct pipe_sampler_state sampler;
-      memset(&sampler, 0, sizeof(sampler));
-      sampler.wrap_s = PIPE_TEX_WRAP_CLAMP;
-      sampler.wrap_t = PIPE_TEX_WRAP_CLAMP;
-      sampler.wrap_r = PIPE_TEX_WRAP_CLAMP;
-      sampler.min_img_filter = PIPE_TEX_FILTER_NEAREST;
-      sampler.min_mip_filter = PIPE_TEX_MIPFILTER_NONE;
-      sampler.mag_img_filter = PIPE_TEX_FILTER_NEAREST;
-      sampler.normalized_coords = 1;
-
-      cso_single_sampler(cso, 0, &sampler);
-      cso_single_sampler_done(cso);
-
-      pipe->set_sampler_textures(pipe, 1, &pt);
+      const struct gl_framebuffer *fb = st->ctx->DrawBuffer;
+      const GLboolean invert = (st_fb_orientation(fb) == Y_0_TOP);
+      const float width = fb->Width;
+      const float height = fb->Height;
+      struct pipe_viewport_state vp;
+      vp.scale[0] =  0.5 * width;
+      vp.scale[1] = height * (invert ? -0.5 : 0.5);
+      vp.scale[2] = 1.0;
+      vp.scale[3] = 1.0;
+      vp.translate[0] = 0.5 * width;
+      vp.translate[1] = 0.5 * height;
+      vp.translate[2] = 0.0;
+      vp.translate[3] = 0.0;
+      cso_set_viewport(cso, &vp);
    }
 
    /* draw textured quad */
@@ -487,6 +493,7 @@ draw_bitmap_quad(GLcontext *ctx, GLint x, GLint y, GLfloat z,
    /* restore state */
    cso_restore_rasterizer(cso);
    cso_restore_samplers(cso);
+   cso_restore_viewport(cso);
    /* shaders don't go through cso yet */
    pipe->bind_fs_state(pipe, st->fp->driver_shader);
    pipe->bind_vs_state(pipe, st->vp->driver_shader);
@@ -742,6 +749,21 @@ st_init_bitmap_functions(struct dd_function_table *functions)
 void
 st_init_bitmap(struct st_context *st)
 {
+   struct pipe_sampler_state *sampler = &st->bitmap.sampler;
+
+   /* init sampler state once */
+   memset(sampler, 0, sizeof(*sampler));
+   sampler->wrap_s = PIPE_TEX_WRAP_CLAMP;
+   sampler->wrap_t = PIPE_TEX_WRAP_CLAMP;
+   sampler->wrap_r = PIPE_TEX_WRAP_CLAMP;
+   sampler->min_img_filter = PIPE_TEX_FILTER_NEAREST;
+   sampler->min_mip_filter = PIPE_TEX_MIPFILTER_NONE;
+   sampler->mag_img_filter = PIPE_TEX_FILTER_NEAREST;
+   sampler->normalized_coords = 1;
+
+   /* init scissor state once */
+   memset(&st->bitmap.rasterizer, 0, sizeof(st->bitmap.rasterizer));
+
    init_bitmap_cache(st);
 }
 
diff --git a/src/mesa/state_tracker/st_context.h b/src/mesa/state_tracker/st_context.h
index 85e3d47e1aa..44705bc89a3 100644
--- a/src/mesa/state_tracker/st_context.h
+++ b/src/mesa/state_tracker/st_context.h
@@ -148,6 +148,8 @@ struct st_context
       struct st_fragment_program *program;  /**< bitmap tex/kil program */
       GLuint user_prog_sn;  /**< user fragment program serial no. */
       struct st_fragment_program *combined_prog;
+      struct pipe_rasterizer_state rasterizer;
+      struct pipe_sampler_state sampler;
       struct pipe_shader_state vert_shader;
       void *vs;
       float vertices[4][3][4];  /**< vertex pos + color + texcoord */