mesa: copy rasterpos evaluation code into core Mesa
authorBrian Paul <brianp@vmware.com>
Wed, 21 Oct 2015 19:39:15 +0000 (13:39 -0600)
committerBrian Paul <brianp@vmware.com>
Thu, 22 Oct 2015 23:19:20 +0000 (17:19 -0600)
We'll remove it from the tnl module next.  By lifting this code into core
Mesa we can use it from the gallium state tracker.

Reviewed-by: Roland Scheidegger <sroland@vmware.com>
src/mesa/main/rastpos.c
src/mesa/main/rastpos.h

index 54b2125a80fcecc3d2a84b422986546933814a06..b468219e688ddd25661fa6b5a1bb6608ba33e227 100644 (file)
 #include "rastpos.h"
 #include "state.h"
 #include "main/dispatch.h"
+#include "main/viewport.h"
+#include "util/simple_list.h"
+
+
+
+/**
+ * Clip a point against the view volume.
+ *
+ * \param v vertex vector describing the point to clip.
+ *
+ * \return zero if outside view volume, or one if inside.
+ */
+static GLuint
+viewclip_point_xy( const GLfloat v[] )
+{
+   if (   v[0] > v[3] || v[0] < -v[3]
+       || v[1] > v[3] || v[1] < -v[3] ) {
+      return 0;
+   }
+   else {
+      return 1;
+   }
+}
+
+
+/**
+ * Clip a point against the far/near Z clipping planes.
+ *
+ * \param v vertex vector describing the point to clip.
+ *
+ * \return zero if outside view volume, or one if inside.
+ */
+static GLuint
+viewclip_point_z( const GLfloat v[] )
+{
+   if (v[2] > v[3] || v[2] < -v[3] ) {
+      return 0;
+   }
+   else {
+      return 1;
+   }
+}
+
+
+/**
+ * Clip a point against the user clipping planes.
+ *
+ * \param ctx GL context.
+ * \param v vertex vector describing the point to clip.
+ *
+ * \return zero if the point was clipped, or one otherwise.
+ */
+static GLuint
+userclip_point( struct gl_context *ctx, const GLfloat v[] )
+{
+   GLuint p;
+
+   for (p = 0; p < ctx->Const.MaxClipPlanes; p++) {
+      if (ctx->Transform.ClipPlanesEnabled & (1 << p)) {
+        GLfloat dot = v[0] * ctx->Transform._ClipUserPlane[p][0]
+                    + v[1] * ctx->Transform._ClipUserPlane[p][1]
+                    + v[2] * ctx->Transform._ClipUserPlane[p][2]
+                    + v[3] * ctx->Transform._ClipUserPlane[p][3];
+         if (dot < 0.0F) {
+            return 0;
+         }
+      }
+   }
+
+   return 1;
+}
+
+
+/**
+ * Compute lighting for the raster position.  RGB modes computed.
+ * \param ctx the context
+ * \param vertex vertex location
+ * \param normal normal vector
+ * \param Rcolor returned color
+ * \param Rspec returned specular color (if separate specular enabled)
+ */
+static void
+shade_rastpos(struct gl_context *ctx,
+              const GLfloat vertex[4],
+              const GLfloat normal[3],
+              GLfloat Rcolor[4],
+              GLfloat Rspec[4])
+{
+   /*const*/ GLfloat (*base)[3] = ctx->Light._BaseColor;
+   const struct gl_light *light;
+   GLfloat diffuseColor[4], specularColor[4];  /* for RGB mode only */
+
+   COPY_3V(diffuseColor, base[0]);
+   diffuseColor[3] = CLAMP(
+      ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_DIFFUSE][3], 0.0F, 1.0F );
+   ASSIGN_4V(specularColor, 0.0, 0.0, 0.0, 1.0);
+
+   foreach (light, &ctx->Light.EnabledList) {
+      GLfloat attenuation = 1.0;
+      GLfloat VP[3]; /* vector from vertex to light pos */
+      GLfloat n_dot_VP;
+      GLfloat diffuseContrib[3], specularContrib[3];
+
+      if (!(light->_Flags & LIGHT_POSITIONAL)) {
+         /* light at infinity */
+        COPY_3V(VP, light->_VP_inf_norm);
+        attenuation = light->_VP_inf_spot_attenuation;
+      }
+      else {
+         /* local/positional light */
+        GLfloat d;
+
+         /* VP = vector from vertex pos to light[i].pos */
+        SUB_3V(VP, light->_Position, vertex);
+         /* d = length(VP) */
+        d = (GLfloat) LEN_3FV( VP );
+        if (d > 1.0e-6F) {
+            /* normalize VP */
+           GLfloat invd = 1.0F / d;
+           SELF_SCALE_SCALAR_3V(VP, invd);
+        }
+
+         /* atti */
+        attenuation = 1.0F / (light->ConstantAttenuation + d *
+                              (light->LinearAttenuation + d *
+                               light->QuadraticAttenuation));
+
+        if (light->_Flags & LIGHT_SPOT) {
+           GLfloat PV_dot_dir = - DOT3(VP, light->_NormSpotDirection);
+
+           if (PV_dot_dir<light->_CosCutoff) {
+              continue;
+           }
+           else {
+               GLfloat spot = powf(PV_dot_dir, light->SpotExponent);
+              attenuation *= spot;
+           }
+        }
+      }
+
+      if (attenuation < 1e-3F)
+        continue;
+
+      n_dot_VP = DOT3( normal, VP );
+
+      if (n_dot_VP < 0.0F) {
+        ACC_SCALE_SCALAR_3V(diffuseColor, attenuation, light->_MatAmbient[0]);
+        continue;
+      }
+
+      /* Ambient + diffuse */
+      COPY_3V(diffuseContrib, light->_MatAmbient[0]);
+      ACC_SCALE_SCALAR_3V(diffuseContrib, n_dot_VP, light->_MatDiffuse[0]);
+
+      /* Specular */
+      {
+         const GLfloat *h;
+         GLfloat n_dot_h;
+
+         ASSIGN_3V(specularContrib, 0.0, 0.0, 0.0);
+
+        if (ctx->Light.Model.LocalViewer) {
+           GLfloat v[3];
+           COPY_3V(v, vertex);
+           NORMALIZE_3FV(v);
+           SUB_3V(VP, VP, v);
+            NORMALIZE_3FV(VP);
+           h = VP;
+        }
+        else if (light->_Flags & LIGHT_POSITIONAL) {
+           ACC_3V(VP, ctx->_EyeZDir);
+            NORMALIZE_3FV(VP);
+           h = VP;
+        }
+         else {
+           h = light->_h_inf_norm;
+        }
+
+        n_dot_h = DOT3(normal, h);
+
+        if (n_dot_h > 0.0F) {
+           GLfloat shine;
+           GLfloat spec_coef;
+
+           shine = ctx->Light.Material.Attrib[MAT_ATTRIB_FRONT_SHININESS][0];
+           spec_coef = powf(n_dot_h, shine);
+
+           if (spec_coef > 1.0e-10F) {
+               if (ctx->Light.Model.ColorControl==GL_SEPARATE_SPECULAR_COLOR) {
+                  ACC_SCALE_SCALAR_3V( specularContrib, spec_coef,
+                                       light->_MatSpecular[0]);
+               }
+               else {
+                  ACC_SCALE_SCALAR_3V( diffuseContrib, spec_coef,
+                                       light->_MatSpecular[0]);
+               }
+           }
+        }
+      }
+
+      ACC_SCALE_SCALAR_3V( diffuseColor, attenuation, diffuseContrib );
+      ACC_SCALE_SCALAR_3V( specularColor, attenuation, specularContrib );
+   }
+
+   Rcolor[0] = CLAMP(diffuseColor[0], 0.0F, 1.0F);
+   Rcolor[1] = CLAMP(diffuseColor[1], 0.0F, 1.0F);
+   Rcolor[2] = CLAMP(diffuseColor[2], 0.0F, 1.0F);
+   Rcolor[3] = CLAMP(diffuseColor[3], 0.0F, 1.0F);
+   Rspec[0] = CLAMP(specularColor[0], 0.0F, 1.0F);
+   Rspec[1] = CLAMP(specularColor[1], 0.0F, 1.0F);
+   Rspec[2] = CLAMP(specularColor[2], 0.0F, 1.0F);
+   Rspec[3] = CLAMP(specularColor[3], 0.0F, 1.0F);
+}
+
+
+/**
+ * Do texgen needed for glRasterPos.
+ * \param ctx  rendering context
+ * \param vObj  object-space vertex coordinate
+ * \param vEye  eye-space vertex coordinate
+ * \param normal  vertex normal
+ * \param unit  texture unit number
+ * \param texcoord  incoming texcoord and resulting texcoord
+ */
+static void
+compute_texgen(struct gl_context *ctx, const GLfloat vObj[4], const GLfloat vEye[4],
+               const GLfloat normal[3], GLuint unit, GLfloat texcoord[4])
+{
+   const struct gl_texture_unit *texUnit = &ctx->Texture.Unit[unit];
+
+   /* always compute sphere map terms, just in case */
+   GLfloat u[3], two_nu, rx, ry, rz, m, mInv;
+   COPY_3V(u, vEye);
+   NORMALIZE_3FV(u);
+   two_nu = 2.0F * DOT3(normal, u);
+   rx = u[0] - normal[0] * two_nu;
+   ry = u[1] - normal[1] * two_nu;
+   rz = u[2] - normal[2] * two_nu;
+   m = rx * rx + ry * ry + (rz + 1.0F) * (rz + 1.0F);
+   if (m > 0.0F)
+      mInv = 0.5F * (1.0f / sqrtf(m));
+   else
+      mInv = 0.0F;
+
+   if (texUnit->TexGenEnabled & S_BIT) {
+      switch (texUnit->GenS.Mode) {
+         case GL_OBJECT_LINEAR:
+            texcoord[0] = DOT4(vObj, texUnit->GenS.ObjectPlane);
+            break;
+         case GL_EYE_LINEAR:
+            texcoord[0] = DOT4(vEye, texUnit->GenS.EyePlane);
+            break;
+         case GL_SPHERE_MAP:
+            texcoord[0] = rx * mInv + 0.5F;
+            break;
+         case GL_REFLECTION_MAP:
+            texcoord[0] = rx;
+            break;
+         case GL_NORMAL_MAP:
+            texcoord[0] = normal[0];
+            break;
+         default:
+            _mesa_problem(ctx, "Bad S texgen in compute_texgen()");
+            return;
+      }
+   }
+
+   if (texUnit->TexGenEnabled & T_BIT) {
+      switch (texUnit->GenT.Mode) {
+         case GL_OBJECT_LINEAR:
+            texcoord[1] = DOT4(vObj, texUnit->GenT.ObjectPlane);
+            break;
+         case GL_EYE_LINEAR:
+            texcoord[1] = DOT4(vEye, texUnit->GenT.EyePlane);
+            break;
+         case GL_SPHERE_MAP:
+            texcoord[1] = ry * mInv + 0.5F;
+            break;
+         case GL_REFLECTION_MAP:
+            texcoord[1] = ry;
+            break;
+         case GL_NORMAL_MAP:
+            texcoord[1] = normal[1];
+            break;
+         default:
+            _mesa_problem(ctx, "Bad T texgen in compute_texgen()");
+            return;
+      }
+   }
+
+   if (texUnit->TexGenEnabled & R_BIT) {
+      switch (texUnit->GenR.Mode) {
+         case GL_OBJECT_LINEAR:
+            texcoord[2] = DOT4(vObj, texUnit->GenR.ObjectPlane);
+            break;
+         case GL_EYE_LINEAR:
+            texcoord[2] = DOT4(vEye, texUnit->GenR.EyePlane);
+            break;
+         case GL_REFLECTION_MAP:
+            texcoord[2] = rz;
+            break;
+         case GL_NORMAL_MAP:
+            texcoord[2] = normal[2];
+            break;
+         default:
+            _mesa_problem(ctx, "Bad R texgen in compute_texgen()");
+            return;
+      }
+   }
+
+   if (texUnit->TexGenEnabled & Q_BIT) {
+      switch (texUnit->GenQ.Mode) {
+         case GL_OBJECT_LINEAR:
+            texcoord[3] = DOT4(vObj, texUnit->GenQ.ObjectPlane);
+            break;
+         case GL_EYE_LINEAR:
+            texcoord[3] = DOT4(vEye, texUnit->GenQ.EyePlane);
+            break;
+         default:
+            _mesa_problem(ctx, "Bad Q texgen in compute_texgen()");
+            return;
+      }
+   }
+}
+
+
+/**
+ * glRasterPos transformation.  Typically called via ctx->Driver.RasterPos().
+ *
+ * \param vObj  vertex position in object space
+ */
+void
+_mesa_RasterPos(struct gl_context *ctx, const GLfloat vObj[4])
+{
+   if (ctx->VertexProgram._Enabled) {
+      /* XXX implement this */
+      _mesa_problem(ctx, "Vertex programs not implemented for glRasterPos");
+      return;
+   }
+   else {
+      GLfloat eye[4], clip[4], ndc[3], d;
+      GLfloat *norm, eyenorm[3];
+      GLfloat *objnorm = ctx->Current.Attrib[VERT_ATTRIB_NORMAL];
+      float scale[3], translate[3];
+
+      /* apply modelview matrix:  eye = MV * obj */
+      TRANSFORM_POINT( eye, ctx->ModelviewMatrixStack.Top->m, vObj );
+      /* apply projection matrix:  clip = Proj * eye */
+      TRANSFORM_POINT( clip, ctx->ProjectionMatrixStack.Top->m, eye );
+
+      /* clip to view volume. */
+      if (!ctx->Transform.DepthClamp) {
+         if (viewclip_point_z(clip) == 0) {
+            ctx->Current.RasterPosValid = GL_FALSE;
+            return;
+         }
+      }
+      if (!ctx->Transform.RasterPositionUnclipped) {
+         if (viewclip_point_xy(clip) == 0) {
+            ctx->Current.RasterPosValid = GL_FALSE;
+            return;
+         }
+      }
+
+      /* clip to user clipping planes */
+      if (ctx->Transform.ClipPlanesEnabled && !userclip_point(ctx, clip)) {
+         ctx->Current.RasterPosValid = GL_FALSE;
+         return;
+      }
+
+      /* ndc = clip / W */
+      d = (clip[3] == 0.0F) ? 1.0F : 1.0F / clip[3];
+      ndc[0] = clip[0] * d;
+      ndc[1] = clip[1] * d;
+      ndc[2] = clip[2] * d;
+      /* wincoord = viewport_mapping(ndc) */
+      _mesa_get_viewport_xform(ctx, 0, scale, translate);
+      ctx->Current.RasterPos[0] = ndc[0] * scale[0] + translate[0];
+      ctx->Current.RasterPos[1] = ndc[1] * scale[1] + translate[1];
+      ctx->Current.RasterPos[2] = ndc[2] * scale[2] + translate[2];
+      ctx->Current.RasterPos[3] = clip[3];
+
+      if (ctx->Transform.DepthClamp) {
+        ctx->Current.RasterPos[3] = CLAMP(ctx->Current.RasterPos[3],
+                                          ctx->ViewportArray[0].Near,
+                                          ctx->ViewportArray[0].Far);
+      }
+
+      /* compute raster distance */
+      if (ctx->Fog.FogCoordinateSource == GL_FOG_COORDINATE_EXT)
+         ctx->Current.RasterDistance = ctx->Current.Attrib[VERT_ATTRIB_FOG][0];
+      else
+         ctx->Current.RasterDistance =
+                        sqrtf( eye[0]*eye[0] + eye[1]*eye[1] + eye[2]*eye[2] );
+
+      /* compute transformed normal vector (for lighting or texgen) */
+      if (ctx->_NeedEyeCoords) {
+         const GLfloat *inv = ctx->ModelviewMatrixStack.Top->inv;
+         TRANSFORM_NORMAL( eyenorm, objnorm, inv );
+         norm = eyenorm;
+      }
+      else {
+         norm = objnorm;
+      }
+
+      /* update raster color */
+      if (ctx->Light.Enabled) {
+         /* lighting */
+         shade_rastpos( ctx, vObj, norm,
+                        ctx->Current.RasterColor,
+                        ctx->Current.RasterSecondaryColor );
+      }
+      else {
+         /* use current color */
+        COPY_4FV(ctx->Current.RasterColor,
+                 ctx->Current.Attrib[VERT_ATTRIB_COLOR0]);
+        COPY_4FV(ctx->Current.RasterSecondaryColor,
+                 ctx->Current.Attrib[VERT_ATTRIB_COLOR1]);
+      }
+
+      /* texture coords */
+      {
+         GLuint u;
+         for (u = 0; u < ctx->Const.MaxTextureCoordUnits; u++) {
+            GLfloat tc[4];
+            COPY_4V(tc, ctx->Current.Attrib[VERT_ATTRIB_TEX0 + u]);
+            if (ctx->Texture.Unit[u].TexGenEnabled) {
+               compute_texgen(ctx, vObj, eye, norm, u, tc);
+            }
+            TRANSFORM_POINT(ctx->Current.RasterTexCoords[u],
+                            ctx->TextureMatrixStack[u].Top->m, tc);
+         }
+      }
+
+      ctx->Current.RasterPosValid = GL_TRUE;
+   }
+
+   if (ctx->RenderMode == GL_SELECT) {
+      _mesa_update_hitflag( ctx, ctx->Current.RasterPos[2] );
+   }
+}
 
 
 /**
index dc28c68d41ba45cac8b07a7cb837f9324f949590..90b8f957b9f3c2676557954134fdcc3a9e71bd8a 100644 (file)
@@ -41,6 +41,9 @@ struct gl_context;
 extern void 
 _mesa_init_rastpos(struct gl_context *ctx);
 
+void
+_mesa_RasterPos(struct gl_context *ctx, const GLfloat vObj[4]);
+
 void GLAPIENTRY
 _mesa_RasterPos2d(GLdouble x, GLdouble y);
 void GLAPIENTRY