softpipe: support all TGSI fragment coord conventions (v4)

Changes in v4:
- Rebase and modify for changes in previous patches

Changes in v3:
- Use positive caps instead of negative caps

Changes in v2:
- Now takes the fragment convention directly from the fragment shader

Adds internal support for all fragment coord conventions to softpipe.

This patch is not required for use with the current state trackers, but it
allows softpipe to run any TGSI program and enhances performance.

diff --git a/src/gallium/drivers/softpipe/sp_screen.c b/src/gallium/drivers/softpipe/sp_screen.c
index 410fabf49097c828755113e6384b2c2e774a0ae7..714a1cf53430f09d7af4ee5385d6355d80b0b484 100644 (file)
--- a/src/gallium/drivers/softpipe/sp_screen.c
+++ b/src/gallium/drivers/softpipe/sp_screen.c
@@ -100,11 +100,10 @@ softpipe_get_param(struct pipe_screen *screen, int param)
    case PIPE_CAP_INDEP_BLEND_FUNC:
       return 1;
    case PIPE_CAP_TGSI_FS_COORD_ORIGIN_UPPER_LEFT:
-   case PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_INTEGER:
-      return 1;
    case PIPE_CAP_TGSI_FS_COORD_ORIGIN_LOWER_LEFT:
    case PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_HALF_INTEGER:
-      return 0;
+   case PIPE_CAP_TGSI_FS_COORD_PIXEL_CENTER_INTEGER:
+      return 1;
    default:
       return 0;
    }

diff --git a/src/gallium/drivers/softpipe/sp_setup.c b/src/gallium/drivers/softpipe/sp_setup.c
index ba1f0f0b2ea7e133a5670d66972be3cfc3c3cb39..bb1bff581cf8a70a0c58f05ef93491c4c8811321 100644 (file)
--- a/src/gallium/drivers/softpipe/sp_setup.c
+++ b/src/gallium/drivers/softpipe/sp_setup.c
@@ -504,21 +504,24 @@ static void tri_persp_coeff( struct setup_context *setup,
 
 /**
  * Special coefficient setup for gl_FragCoord.
- * X and Y are trivial, though Y has to be inverted for OpenGL.
+ * X and Y are trivial, though Y may have to be inverted for OpenGL.
  * Z and W are copied from posCoef which should have already been computed.
  * We could do a bit less work if we'd examine gl_FragCoord's swizzle mask.
  */
 static void
 setup_fragcoord_coeff(struct setup_context *setup, uint slot)
 {
+   struct sp_fragment_shader* spfs = setup->softpipe->fs;
    /*X*/
-   setup->coef[slot].a0[0] = 0;
+   setup->coef[slot].a0[0] = spfs->pixel_center_integer ? 0.0 : 0.5;
    setup->coef[slot].dadx[0] = 1.0;
    setup->coef[slot].dady[0] = 0.0;
    /*Y*/
-   setup->coef[slot].a0[1] = 0.0;
+   setup->coef[slot].a0[1] =
+                  (spfs->origin_lower_left ? setup->softpipe->framebuffer.height : 0)
+                  + (spfs->pixel_center_integer ? 0.0 : 0.5);
    setup->coef[slot].dadx[1] = 0.0;
-   setup->coef[slot].dady[1] = 1.0;
+   setup->coef[slot].dady[1] = spfs->origin_lower_left ? -1.0 : 1.0;
    /*Z*/
    setup->coef[slot].a0[2] = setup->posCoef.a0[2];
    setup->coef[slot].dadx[2] = setup->posCoef.dadx[2];

diff --git a/src/gallium/drivers/softpipe/sp_state.h b/src/gallium/drivers/softpipe/sp_state.h
index 7f244c4fd49c4e44aeff0b8bf99fccef15b0abda..a83cae73617561b42ea9ec202691851ae1964037 100644 (file)
--- a/src/gallium/drivers/softpipe/sp_state.h
+++ b/src/gallium/drivers/softpipe/sp_state.h
@@ -68,6 +68,9 @@ struct sp_fragment_shader {
 
    struct tgsi_shader_info info;
 
+   boolean origin_lower_left; /**< fragment shader uses lower left position origin? */
+   boolean pixel_center_integer; /**< fragment shader uses integer pixel center? */
+
    void (*prepare)( const struct sp_fragment_shader *shader,
                    struct tgsi_exec_machine *machine,
                    struct tgsi_sampler **samplers);

diff --git a/src/gallium/drivers/softpipe/sp_state_fs.c b/src/gallium/drivers/softpipe/sp_state_fs.c
index 04bdcaacc2500c10179c58fa18b19fb8c0b3a9b0..de3edde97603cb637e51ca37272bdfc3d49a05da 100644 (file)
--- a/src/gallium/drivers/softpipe/sp_state_fs.c
+++ b/src/gallium/drivers/softpipe/sp_state_fs.c
@@ -44,6 +44,7 @@ softpipe_create_fs_state(struct pipe_context *pipe,
 {
    struct softpipe_context *softpipe = softpipe_context(pipe);
    struct sp_fragment_shader *state;
+   unsigned i;
 
    /* debug */
    if (softpipe->dump_fs) 
@@ -60,6 +61,13 @@ softpipe_create_fs_state(struct pipe_context *pipe,
    /* get/save the summary info for this shader */
    tgsi_scan_shader(templ->tokens, &state->info);
 
+   for (i = 0; i < state->info.num_properties; ++i) {
+      if (state->info.properties[i].name == TGSI_PROPERTY_FS_COORD_ORIGIN)
+         state->origin_lower_left = state->info.properties[i].data[0];
+      else if (state->info.properties[i].name == TGSI_PROPERTY_FS_COORD_PIXEL_CENTER)
+        state->pixel_center_integer = state->info.properties[i].data[0];
+   }
+
    return state;
 }