Update glClear and glDrawPixels code.

Since they're implemented by drawing quadrilaterals (and go through vertex
transformation and viewport mapping) we don't have to invert Y coords.

3 files changed, 95 insertions, 17 deletions

diff --git a/src/mesa/pipe/draw/draw_arrays.c b/src/mesa/pipe/draw/draw_arrays.c
index 17ed255f85a..34a031ddf06 100644
--- a/src/mesa/pipe/draw/draw_arrays.c
+++ b/src/mesa/pipe/draw/draw_arrays.c
@@ -248,10 +248,11 @@ run_vertex_program(struct draw_context *draw,
       vOut[j]->data[0][2] = z * scale[2] + trans[2];
       vOut[j]->data[0][3] = w;
 #if 0
-      printf("wincoord: %f %f %f\n",
+      printf("wincoord: %f %f %f %f\n",
              vOut[j]->data[0][0],
              vOut[j]->data[0][1],
-             vOut[j]->data[0][2]);
+             vOut[j]->data[0][2],
+             vOut[j]->data[0][3]);
 #endif
 
       /* remaining attributes: */
diff --git a/src/mesa/state_tracker/st_cb_clear.c b/src/mesa/state_tracker/st_cb_clear.c
index bd050ca2cdc..1ed48facd1f 100644
--- a/src/mesa/state_tracker/st_cb_clear.c
+++ b/src/mesa/state_tracker/st_cb_clear.c
@@ -212,8 +212,8 @@ make_vertex_shader(struct st_context *st)
 
 /**
  * Draw a screen-aligned quadrilateral.
- * Coords are window coords.
- * XXX need to emit clip coords when using a vertex program!
+ * Coords are window coords with y=0=bottom.  These coords will be transformed
+ * by the vertex shader and viewport transform (which will flip Y if needed).
  */
 static void
 draw_quad(GLcontext *ctx,
@@ -266,9 +266,9 @@ clear_with_quad(GLcontext *ctx,
 {
    struct st_context *st = ctx->st;
    const GLfloat x0 = ctx->DrawBuffer->_Xmin;
-   const GLfloat y0 = ctx->DrawBuffer->Height - ctx->DrawBuffer->_Ymax;
+   const GLfloat y0 = ctx->DrawBuffer->_Ymin;
    const GLfloat x1 = ctx->DrawBuffer->_Xmax;
-   const GLfloat y1 = ctx->DrawBuffer->Height - ctx->DrawBuffer->_Ymin;
+   const GLfloat y1 = ctx->DrawBuffer->_Ymax;
 
    /* alpha state: disabled */
    {
@@ -312,8 +312,13 @@ clear_with_quad(GLcontext *ctx,
    {
       struct pipe_setup_state setup;
       memset(&setup, 0, sizeof(setup));
+#if 0
+      /* don't do per-pixel scissor; we'll just draw a PIPE_PRIM_QUAD
+       * that matches the scissor bounds.
+       */
       if (ctx->Scissor.Enabled)
          setup.scissor = 1;
+#endif
       st->pipe->set_setup_state(st->pipe, &setup);
    }
 
diff --git a/src/mesa/state_tracker/st_cb_drawpixels.c b/src/mesa/state_tracker/st_cb_drawpixels.c
index 1aa56fcf8bc..108304f5e27 100644
--- a/src/mesa/state_tracker/st_cb_drawpixels.c
+++ b/src/mesa/state_tracker/st_cb_drawpixels.c
@@ -49,11 +49,11 @@
 
 
 /**
- * Create a simple fragment shader that passes the texture color through
- * to the fragment color.
+ * Create a simple fragment shader that does a TEX() instruction to get
+ * the fragment color.
  */
 static struct st_fragment_program *
-make_drawpixels_shader(struct st_context *st)
+make_fragment_shader(struct st_context *st)
 {
    GLcontext *ctx = st->ctx;
    struct st_fragment_program *stfp;
@@ -95,6 +95,59 @@ make_drawpixels_shader(struct st_context *st)
 }
 
 
+/**
+ * Create a simple vertex shader that just passes through the
+ * vertex position and color.
+ */
+static struct st_vertex_program *
+make_vertex_shader(struct st_context *st)
+{
+   GLcontext *ctx = st->ctx;
+   struct st_vertex_program *stvp;
+   struct gl_program *p;
+   GLboolean b;
+
+   p = ctx->Driver.NewProgram(ctx, GL_VERTEX_PROGRAM_ARB, 0);
+   if (!p)
+      return NULL;
+
+   p->NumInstructions = 3;
+   p->Instructions = _mesa_alloc_instructions(3);
+   if (!p->Instructions) {
+      ctx->Driver.DeleteProgram(ctx, p);
+      return NULL;
+   }
+   _mesa_init_instructions(p->Instructions, 3);
+   /* MOV result.pos, vertex.pos; */
+   p->Instructions[0].Opcode = OPCODE_MOV;
+   p->Instructions[0].DstReg.File = PROGRAM_OUTPUT;
+   p->Instructions[0].DstReg.Index = VERT_RESULT_HPOS;
+   p->Instructions[0].SrcReg[0].File = PROGRAM_INPUT;
+   p->Instructions[0].SrcReg[0].Index = VERT_ATTRIB_POS;
+   /* MOV result.color, vertex.color; */
+   p->Instructions[1].Opcode = OPCODE_MOV;
+   p->Instructions[1].DstReg.File = PROGRAM_OUTPUT;
+   p->Instructions[1].DstReg.Index = VERT_RESULT_TEX0;
+   p->Instructions[1].SrcReg[0].File = PROGRAM_INPUT;
+   p->Instructions[1].SrcReg[0].Index = VERT_ATTRIB_TEX0;
+   /* END; */
+   p->Instructions[2].Opcode = OPCODE_END;
+
+   p->InputsRead = VERT_BIT_POS | VERT_BIT_TEX0;
+   p->OutputsWritten = ((1 << VERT_RESULT_TEX0) |
+                        (1 << VERT_RESULT_HPOS));
+
+   stvp = (struct st_vertex_program *) p;
+   /* compile into tgsi format */
+   b = tgsi_mesa_compile_vp_program(&stvp->Base,
+                                    stvp->tokens, ST_FP_MAX_TOKENS);
+   assert(b);
+
+   return stvp;
+}
+
+
+
 static struct pipe_mipmap_tree *
 make_mipmap_tree(struct st_context *st,
                  GLsizei width, GLsizei height, GLenum format, GLenum type,
@@ -156,7 +209,7 @@ make_mipmap_tree(struct st_context *st,
       assert(success);
    }
 
-   mt->target = GL_TEXTURE_2D;
+   mt->target = PIPE_TEXTURE_2D;
    mt->internal_format = GL_RGBA;
    mt->format = pipeFormat;
    mt->first_level = 0;
@@ -191,7 +244,7 @@ free_mipmap_tree(struct pipe_context *pipe, struct pipe_mipmap_tree *mt)
 
 /**
  * Draw textured quad.
- * Y=0=top
+ * Coords are window coords with y=0=bottom.
  */
 static void
 draw_quad(GLcontext *ctx, GLfloat x0, GLfloat y0, GLfloat z,
@@ -236,7 +289,7 @@ draw_quad(GLcontext *ctx, GLfloat x0, GLfloat y0, GLfloat z,
       verts[i][1][3] = 1.0; /*Q*/
    }
 
-   st_draw_vertices(ctx, PIPE_PRIM_QUADS, 4, (GLfloat *) verts, 2, attribs);
+   st_draw_vertices(ctx, PIPE_PRIM_QUADS, 4, (float *) verts, 2, attribs);
 }
 
 
@@ -269,12 +322,12 @@ draw_textured_quad(GLcontext *ctx, GLint x, GLint y, GLfloat z,
       pipe->set_setup_state(pipe, &setup);
    }
 
-   /* fragment shader state: color pass-through program */
+   /* fragment shader state: TEX lookup program */
    {
       static struct st_fragment_program *stfp = NULL;
       struct pipe_shader_state fs;
       if (!stfp) {
-         stfp = make_drawpixels_shader(ctx->st);
+         stfp = make_fragment_shader(ctx->st);
       }
       memset(&fs, 0, sizeof(fs));
       fs.inputs_read = stfp->Base.Base.InputsRead;
@@ -283,6 +336,21 @@ draw_textured_quad(GLcontext *ctx, GLint x, GLint y, GLfloat z,
       pipe->set_fs_state(pipe, &fs);
    }
 
+   /* vertex shader state: position + texcoord pass-through */
+   {
+      static struct st_vertex_program *stvp = NULL;
+      struct pipe_shader_state vs;
+      if (!stvp) {
+         stvp = make_vertex_shader(ctx->st);
+      }
+      memset(&vs, 0, sizeof(vs));
+      vs.inputs_read = stvp->Base.Base.InputsRead;
+      vs.outputs_written = stvp->Base.Base.OutputsWritten;
+      vs.tokens = &stvp->tokens[0];
+      vs.constants = NULL;
+      pipe->set_vs_state(pipe, &vs);
+   }
+
    /* texture sampling state: */
    {
       struct pipe_sampler_state sampler;
@@ -303,11 +371,14 @@ draw_textured_quad(GLcontext *ctx, GLint x, GLint y, GLfloat z,
       pipe->set_texture_state(pipe, unit, mt);
    }
 
-   /* compute window coords (y=0=top) with pixel zoom */
+   /* Compute window coords (y=0=bottom) with pixel zoom.
+    * Recall that these coords are transformed by the current
+    * vertex shader and viewport transformation.
+    */
    x0 = x;
-   y0 = ctx->DrawBuffer->Height - 1 - y;
    x1 = x + width * ctx->Pixel.ZoomX;
-   y1 = ctx->DrawBuffer->Height - 1 - (y + height * ctx->Pixel.ZoomY);
+   y0 = y;
+   y1 = y + height * ctx->Pixel.ZoomY;
 
    /* draw textured quad */
    draw_quad(ctx, x0, y0, z, x1, y1);
@@ -315,6 +386,7 @@ draw_textured_quad(GLcontext *ctx, GLint x, GLint y, GLfloat z,
    /* restore GL state */
    pipe->set_setup_state(pipe, &ctx->st->state.setup);
    pipe->set_fs_state(pipe, &ctx->st->state.fs);
+   pipe->set_vs_state(pipe, &ctx->st->state.vs);
    pipe->set_texture_state(pipe, unit, ctx->st->state.texture[unit]);
    pipe->set_sampler_state(pipe, unit, &ctx->st->state.sampler[unit]);