vc4: Add support for GL 1.1's stupid CLAMP mode.

We just clamp the incoming texture coordinates.  This breaks the lambda
calculation, but it gets the piglit tests to pass.  This is the same
behavior as in i965.

diff --git a/src/gallium/drivers/vc4/vc4_program.c b/src/gallium/drivers/vc4/vc4_program.c
index e16b2ce..64faf6f 100644 (file)
--- a/src/gallium/drivers/vc4/vc4_program.c
+++ b/src/gallium/drivers/vc4/vc4_program.c
@@ -545,6 +545,16 @@ tgsi_to_qir_tex(struct vc4_compile *c,
                           texture_u[next_texture_u++]);
         }
 
+        if (c->key->tex[unit].wrap_s == PIPE_TEX_WRAP_CLAMP) {
+                s = qir_FMIN(c, qir_FMAX(c, s, qir_uniform_f(c, 0.0)),
+                             qir_uniform_f(c, 1.0));
+        }
+
+        if (c->key->tex[unit].wrap_t == PIPE_TEX_WRAP_CLAMP) {
+                t = qir_FMIN(c, qir_FMAX(c, t, qir_uniform_f(c, 0.0)),
+                             qir_uniform_f(c, 1.0));
+        }
+
         qir_TEX_T(c, t, texture_u[next_texture_u++]);
 
         if (tgsi_inst->Instruction.Opcode == TGSI_OPCODE_TXB)
@@ -1892,18 +1902,19 @@ vc4_shader_state_delete(struct pipe_context *pctx, void *hwcso)
         free(so);
 }
 
-static uint32_t translate_wrap(uint32_t p_wrap)
+static uint32_t translate_wrap(uint32_t p_wrap, bool using_nearest)
 {
         switch (p_wrap) {
         case PIPE_TEX_WRAP_REPEAT:
                 return 0;
-        case PIPE_TEX_WRAP_CLAMP:
         case PIPE_TEX_WRAP_CLAMP_TO_EDGE:
                 return 1;
         case PIPE_TEX_WRAP_MIRROR_REPEAT:
                 return 2;
         case PIPE_TEX_WRAP_CLAMP_TO_BORDER:
                 return 3;
+        case PIPE_TEX_WRAP_CLAMP:
+                return (using_nearest ? 1 : 3);
         default:
                 fprintf(stderr, "Unknown wrap mode %d\n", p_wrap);
                 assert(!"not reached");
@@ -1945,6 +1956,10 @@ write_texture_p1(struct vc4_context *vc4,
                 [PIPE_TEX_FILTER_LINEAR] = 0,
         };
 
+        bool either_nearest =
+                (sampler->mag_img_filter == PIPE_TEX_MIPFILTER_NEAREST ||
+                 sampler->min_img_filter == PIPE_TEX_MIPFILTER_NEAREST);
+
         cl_u32(&vc4->uniforms,
                ((rsc->vc4_format >> 4) << 31) |
                (texture->texture->height0 << 20) |
@@ -1952,8 +1967,8 @@ write_texture_p1(struct vc4_context *vc4,
                (imgfilter_map[sampler->mag_img_filter] << 7) |
                ((imgfilter_map[sampler->min_img_filter] +
                  mipfilter_map[sampler->min_mip_filter]) << 4) |
-               (translate_wrap(sampler->wrap_t) << 2) |
-               (translate_wrap(sampler->wrap_s) << 0));
+               (translate_wrap(sampler->wrap_t, either_nearest) << 2) |
+               (translate_wrap(sampler->wrap_s, either_nearest) << 0));
 }
 
 static void