path: root/src/mesa/shader/uniforms.c

/*
 * Mesa 3-D graphics library
 *
 * Copyright (C) 2004-2008  Brian Paul   All Rights Reserved.
 * Copyright (C) 2009-2010  VMware, Inc.  All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

/**
 * \file uniforms.c
 * Functions related to GLSL uniform variables.
 * \author Brian Paul
 */

/**
 * XXX things to do:
 * 1. Check that the right error code is generated for all _mesa_error() calls.
 * 2. Insert FLUSH_VERTICES calls in various places
 */


#include "main/glheader.h"
#include "main/context.h"
#include "shader/prog_parameter.h"
#include "shader/prog_statevars.h"
#include "shader/prog_uniform.h"
#include "shader/shader_api.h"
#include "uniforms.h"



static GLenum
base_uniform_type(GLenum type)
{
   switch (type) {
#if 0 /* not needed, for now */
   case GL_BOOL:
   case GL_BOOL_VEC2:
   case GL_BOOL_VEC3:
   case GL_BOOL_VEC4:
      return GL_BOOL;
#endif
   case GL_FLOAT:
   case GL_FLOAT_VEC2:
   case GL_FLOAT_VEC3:
   case GL_FLOAT_VEC4:
      return GL_FLOAT;
   case GL_UNSIGNED_INT:
   case GL_UNSIGNED_INT_VEC2:
   case GL_UNSIGNED_INT_VEC3:
   case GL_UNSIGNED_INT_VEC4:
      return GL_UNSIGNED_INT;
   case GL_INT:
   case GL_INT_VEC2:
   case GL_INT_VEC3:
   case GL_INT_VEC4:
      return GL_INT;
   default:
      _mesa_problem(NULL, "Invalid type in base_uniform_type()");
      return GL_FLOAT;
   }
}


static GLboolean
is_boolean_type(GLenum type)
{
   switch (type) {
   case GL_BOOL:
   case GL_BOOL_VEC2:
   case GL_BOOL_VEC3:
   case GL_BOOL_VEC4:
      return GL_TRUE;
   default:
      return GL_FALSE;
   }
}


static GLboolean
is_sampler_type(GLenum type)
{
   switch (type) {
   case GL_SAMPLER_1D:
   case GL_SAMPLER_2D:
   case GL_SAMPLER_3D:
   case GL_SAMPLER_CUBE:
   case GL_SAMPLER_1D_SHADOW:
   case GL_SAMPLER_2D_SHADOW:
   case GL_SAMPLER_2D_RECT_ARB:
   case GL_SAMPLER_2D_RECT_SHADOW_ARB:
   case GL_SAMPLER_1D_ARRAY_EXT:
   case GL_SAMPLER_2D_ARRAY_EXT:
   case GL_SAMPLER_1D_ARRAY_SHADOW_EXT:
   case GL_SAMPLER_2D_ARRAY_SHADOW_EXT:
      return GL_TRUE;
   default:
      return GL_FALSE;
   }
}


static struct gl_program_parameter *
get_uniform_parameter(const struct gl_shader_program *shProg, GLuint index)
{
   const struct gl_program *prog = NULL;
   GLint progPos;

   progPos = shProg->Uniforms->Uniforms[index].VertPos;
   if (progPos >= 0) {
      prog = &shProg->VertexProgram->Base;
   }
   else {
      progPos = shProg->Uniforms->Uniforms[index].FragPos;
      if (progPos >= 0) {
         prog = &shProg->FragmentProgram->Base;
      }
   }

   if (!prog || progPos < 0)
      return NULL; /* should never happen */

   return &prog->Parameters->Parameters[progPos];
}


/**
 * Called via ctx->Driver.GetActiveUniform().
 */
static void
_mesa_get_active_uniform(GLcontext *ctx, GLuint program, GLuint index,
                         GLsizei maxLength, GLsizei *length, GLint *size,
                         GLenum *type, GLchar *nameOut)
{
   const struct gl_shader_program *shProg;
   const struct gl_program *prog = NULL;
   const struct gl_program_parameter *param;
   GLint progPos;

   shProg = _mesa_lookup_shader_program_err(ctx, program, "glGetActiveUniform");
   if (!shProg)
      return;

   if (!shProg->Uniforms || index >= shProg->Uniforms->NumUniforms) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glGetActiveUniform(index)");
      return;
   }

   progPos = shProg->Uniforms->Uniforms[index].VertPos;
   if (progPos >= 0) {
      prog = &shProg->VertexProgram->Base;
   }
   else {
      progPos = shProg->Uniforms->Uniforms[index].FragPos;
      if (progPos >= 0) {
         prog = &shProg->FragmentProgram->Base;
      }
   }

   if (!prog || progPos < 0)
      return; /* should never happen */

   ASSERT(progPos < prog->Parameters->NumParameters);
   param = &prog->Parameters->Parameters[progPos];

   if (nameOut) {
      _mesa_copy_string(nameOut, maxLength, length, param->Name);
   }

   if (size) {
      GLint typeSize = _mesa_sizeof_glsl_type(param->DataType);
      if ((GLint) param->Size > typeSize) {
         /* This is an array.
          * Array elements are placed on vector[4] boundaries so they're
          * a multiple of four floats.  We round typeSize up to next multiple
          * of four to get the right size below.
          */
         typeSize = (typeSize + 3) & ~3;
      }
      /* Note that the returned size is in units of the <type>, not bytes */
      *size = param->Size / typeSize;
   }

   if (type) {
      *type = param->DataType;
   }
}



static void
get_matrix_dims(GLenum type, GLint *rows, GLint *cols)
{
   switch (type) {
   case GL_FLOAT_MAT2:
      *rows = *cols = 2;
      break;
   case GL_FLOAT_MAT2x3:
      *rows = 3;
      *cols = 2;
      break;
   case GL_FLOAT_MAT2x4:
      *rows = 4;
      *cols = 2;
      break;
   case GL_FLOAT_MAT3:
      *rows = 3;
      *cols = 3;
      break;
   case GL_FLOAT_MAT3x2:
      *rows = 2;
      *cols = 3;
      break;
   case GL_FLOAT_MAT3x4:
      *rows = 4;
      *cols = 3;
      break;
   case GL_FLOAT_MAT4:
      *rows = 4;
      *cols = 4;
      break;
   case GL_FLOAT_MAT4x2:
      *rows = 2;
      *cols = 4;
      break;
   case GL_FLOAT_MAT4x3:
      *rows = 3;
      *cols = 4;
      break;
   default:
      *rows = *cols = 0;
   }
}


/**
 * Determine the number of rows and columns occupied by a uniform
 * according to its datatype.  For non-matrix types (such as GL_FLOAT_VEC4),
 * the number of rows = 1 and cols = number of elements in the vector.
 */
static void
get_uniform_rows_cols(const struct gl_program_parameter *p,
                      GLint *rows, GLint *cols)
{
   get_matrix_dims(p->DataType, rows, cols);
   if (*rows == 0 && *cols == 0) {
      /* not a matrix type, probably a float or vector */
      if (p->Size <= 4) {
         *rows = 1;
         *cols = p->Size;
      }
      else {
         *rows = p->Size / 4 + 1;
         if (p->Size % 4 == 0)
            *cols = 4;
         else
            *cols = p->Size % 4;
      }
   }
}


/**
 * Helper for get_uniform[fi]v() functions.
 * Given a shader program name and uniform location, return a pointer
 * to the shader program and return the program parameter position.
 */
static void
lookup_uniform_parameter(GLcontext *ctx, GLuint program, GLint location,
                         struct gl_program **progOut, GLint *paramPosOut)
{
   struct gl_shader_program *shProg
      = _mesa_lookup_shader_program_err(ctx, program, "glGetUniform[if]v");
   struct gl_program *prog = NULL;
   GLint progPos = -1;

   /* if shProg is NULL, we'll have already recorded an error */

   if (shProg) {
      if (!shProg->Uniforms ||
          location < 0 ||
          location >= (GLint) shProg->Uniforms->NumUniforms) {
         _mesa_error(ctx, GL_INVALID_OPERATION,  "glGetUniformfv(location)");
      }
      else {
         /* OK, find the gl_program and program parameter location */
         progPos = shProg->Uniforms->Uniforms[location].VertPos;
         if (progPos >= 0) {
            prog = &shProg->VertexProgram->Base;
         }
         else {
            progPos = shProg->Uniforms->Uniforms[location].FragPos;
            if (progPos >= 0) {
               prog = &shProg->FragmentProgram->Base;
            }
         }
      }
   }

   *progOut = prog;
   *paramPosOut = progPos;
}


/**
 * GLGL uniform arrays and structs require special handling.
 *
 * The GL_ARB_shader_objects spec says that if you use
 * glGetUniformLocation to get the location of an array, you CANNOT
 * access other elements of the array by adding an offset to the
 * returned location.  For example, you must call
 * glGetUniformLocation("foo[16]") if you want to set the 16th element
 * of the array with glUniform().
 *
 * HOWEVER, some other OpenGL drivers allow accessing array elements
 * by adding an offset to the returned array location.  And some apps
 * seem to depend on that behaviour.
 *
 * Mesa's gl_uniform_list doesn't directly support this since each
 * entry in the list describes one uniform variable, not one uniform
 * element.  We could insert dummy entries in the list for each array
 * element after [0] but that causes complications elsewhere.
 *
 * We solve this problem by encoding two values in the location that's
 * returned by glGetUniformLocation():
 *  a) index into gl_uniform_list::Uniforms[] for the uniform
 *  b) an array/field offset (0 for simple types)
 *
 * These two values are encoded in the high and low halves of a GLint.
 * By putting the uniform number in the high part and the offset in the
 * low part, we can support the unofficial ability to index into arrays
 * by adding offsets to the location value.
 */
static void
merge_location_offset(GLint *location, GLint offset)
{
   *location = (*location << 16) | offset;
}


/**
 * Separate the uniform location and parameter offset.  See above.
 */
static void
split_location_offset(GLint *location, GLint *offset)
{
   *offset = *location & 0xffff;
   *location = *location >> 16;
}



/**
 * Called via ctx->Driver.GetUniformfv().
 */
static void
_mesa_get_uniformfv(GLcontext *ctx, GLuint program, GLint location,
                    GLfloat *params)
{
   struct gl_program *prog;
   GLint paramPos;
   GLint offset;

   split_location_offset(&location, &offset);

   lookup_uniform_parameter(ctx, program, location, &prog, &paramPos);

   if (prog) {
      const struct gl_program_parameter *p =
         &prog->Parameters->Parameters[paramPos];
      GLint rows, cols, i, j, k;

      get_uniform_rows_cols(p, &rows, &cols);

      k = 0;
      for (i = 0; i < rows; i++) {
         for (j = 0; j < cols; j++ ) {
            params[k++] = prog->Parameters->ParameterValues[paramPos+i][j];
         }
      }
   }
}


/**
 * Called via ctx->Driver.GetUniformiv().
 * \sa _mesa_get_uniformfv, only difference is a cast.
 */
static void
_mesa_get_uniformiv(GLcontext *ctx, GLuint program, GLint location,
                    GLint *params)
{
   struct gl_program *prog;
   GLint paramPos;
   GLint offset;

   split_location_offset(&location, &offset);

   lookup_uniform_parameter(ctx, program, location, &prog, &paramPos);

   if (prog) {
      const struct gl_program_parameter *p =
         &prog->Parameters->Parameters[paramPos];
      GLint rows, cols, i, j, k;

      get_uniform_rows_cols(p, &rows, &cols);

      k = 0;
      for (i = 0; i < rows; i++) {
         for (j = 0; j < cols; j++ ) {
            params[k++] = (GLint) prog->Parameters->ParameterValues[paramPos+i][j];
         }
      }
   }
}


/**
 * Called via ctx->Driver.GetUniformLocation().
 *
 * The return value will encode two values, the uniform location and an
 * offset (used for arrays, structs).
 */
static GLint
_mesa_get_uniform_location(GLcontext *ctx, GLuint program, const GLchar *name)
{
   GLint offset = 0, location = -1;

   struct gl_shader_program *shProg =
      _mesa_lookup_shader_program_err(ctx, program, "glGetUniformLocation");

   if (!shProg)
      return -1;

   if (shProg->LinkStatus == GL_FALSE) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glGetUniformfv(program)");
      return -1;
   }

   /* XXX we should return -1 if the uniform was declared, but not
    * actually used.
    */

   /* XXX we need to be able to parse uniform names for structs and arrays
    * such as:
    *   mymatrix[1]
    *   mystruct.field1
    */

   {
      /* handle 1-dimension arrays here... */
      char *c = strchr(name, '[');
      if (c) {
         /* truncate name at [ */
         const GLint len = c - name;
         GLchar *newName = malloc(len + 1);
         if (!newName)
            return -1; /* out of mem */
         memcpy(newName, name, len);
         newName[len] = 0;

         location = _mesa_lookup_uniform(shProg->Uniforms, newName);
         if (location >= 0) {
            const GLint element = atoi(c + 1);
            if (element > 0) {
               /* get type of the uniform array element */
               struct gl_program_parameter *p;
               p = get_uniform_parameter(shProg, location);
               if (p) {
                  GLint rows, cols;
                  get_matrix_dims(p->DataType, &rows, &cols);
                  if (rows < 1)
                     rows = 1;
                  offset = element * rows;
               }
            }
         }

         free(newName);
      }
   }

   if (location < 0) {
      location = _mesa_lookup_uniform(shProg->Uniforms, name);
   }

   if (location >= 0) {
      merge_location_offset(&location, offset);
   }

   return location;
}


/**
 * Check if the type given by userType is allowed to set a uniform of the
 * target type.  Generally, equivalence is required, but setting Boolean
 * uniforms can be done with glUniformiv or glUniformfv.
 */
static GLboolean
compatible_types(GLenum userType, GLenum targetType)
{
   if (userType == targetType)
      return GL_TRUE;

   if (targetType == GL_BOOL && (userType == GL_FLOAT ||
                                 userType == GL_UNSIGNED_INT ||
                                 userType == GL_INT))
      return GL_TRUE;

   if (targetType == GL_BOOL_VEC2 && (userType == GL_FLOAT_VEC2 ||
                                      userType == GL_UNSIGNED_INT_VEC2 ||
                                      userType == GL_INT_VEC2))
      return GL_TRUE;

   if (targetType == GL_BOOL_VEC3 && (userType == GL_FLOAT_VEC3 ||
                                      userType == GL_UNSIGNED_INT_VEC3 ||
                                      userType == GL_INT_VEC3))
      return GL_TRUE;

   if (targetType == GL_BOOL_VEC4 && (userType == GL_FLOAT_VEC4 ||
                                      userType == GL_UNSIGNED_INT_VEC4 ||
                                      userType == GL_INT_VEC4))
      return GL_TRUE;

   if (is_sampler_type(targetType) && userType == GL_INT)
      return GL_TRUE;

   return GL_FALSE;
}


/**
 * Set the value of a program's uniform variable.
 * \param program  the program whose uniform to update
 * \param index  the index of the program parameter for the uniform
 * \param offset  additional parameter slot offset (for arrays)
 * \param type  the incoming datatype of 'values'
 * \param count  the number of uniforms to set
 * \param elems  number of elements per uniform (1, 2, 3 or 4)
 * \param values  the new values, of datatype 'type'
 */
static void
set_program_uniform(GLcontext *ctx, struct gl_program *program,
                    GLint index, GLint offset,
                    GLenum type, GLsizei count, GLint elems,
                    const void *values)
{
   const struct gl_program_parameter *param =
      &program->Parameters->Parameters[index];

   assert(offset >= 0);
   assert(elems >= 1);
   assert(elems <= 4);

   if (!compatible_types(type, param->DataType)) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glUniform(type mismatch)");
      return;
   }

   if (index + offset > (GLint) program->Parameters->Size) {
      /* out of bounds! */
      return;
   }

   if (param->Type == PROGRAM_SAMPLER) {
      /* This controls which texture unit which is used by a sampler */
      GLboolean changed = GL_FALSE;
      GLint i;

      /* this should have been caught by the compatible_types() check */
      ASSERT(type == GL_INT);

      /* loop over number of samplers to change */
      for (i = 0; i < count; i++) {
         GLuint sampler =
            (GLuint) program->Parameters->ParameterValues[index + offset + i][0];
         GLuint texUnit = ((GLuint *) values)[i];

         /* check that the sampler (tex unit index) is legal */
         if (texUnit >= ctx->Const.MaxTextureImageUnits) {
            _mesa_error(ctx, GL_INVALID_VALUE,
                        "glUniform1(invalid sampler/tex unit index for '%s')",
                        param->Name);
            return;
         }

         /* This maps a sampler to a texture unit: */
         if (sampler < MAX_SAMPLERS) {
#if 0
            printf("Set program %p sampler %d '%s' to unit %u\n",
		   program, sampler, param->Name, texUnit);
#endif
            if (program->SamplerUnits[sampler] != texUnit) {
               program->SamplerUnits[sampler] = texUnit;
               changed = GL_TRUE;
            }
         }
      }

      if (changed) {
         /* When a sampler's value changes it usually requires rewriting
          * a GPU program's TEX instructions since there may not be a
          * sampler->texture lookup table.  We signal this with the
          * ProgramStringNotify() callback.
          */
         FLUSH_VERTICES(ctx, _NEW_TEXTURE | _NEW_PROGRAM);
         _mesa_update_shader_textures_used(program);
         /* Do we need to care about the return value here?
          * This should not be the first time the driver was notified of
          * this program.
          */
         (void) ctx->Driver.ProgramStringNotify(ctx, program->Target, program);
      }
   }
   else {
      /* ordinary uniform variable */
      const GLboolean isUniformBool = is_boolean_type(param->DataType);
      const GLenum basicType = base_uniform_type(type);
      const GLint slots = (param->Size + 3) / 4;
      const GLint typeSize = _mesa_sizeof_glsl_type(param->DataType);
      GLsizei k, i;

      if ((GLint) param->Size > typeSize) {
         /* an array */
         /* we'll ignore extra data below */
      }
      else {
         /* non-array: count must be at most one; count == 0 is handled by the loop below */
         if (count > 1) {
            _mesa_error(ctx, GL_INVALID_OPERATION,
                        "glUniform(uniform '%s' is not an array)",
                        param->Name);
            return;
         }
      }

      /* loop over number of array elements */
      for (k = 0; k < count; k++) {
         GLfloat *uniformVal;

         if (offset + k >= slots) {
            /* Extra array data is ignored */
            break;
         }

         /* uniformVal (the destination) is always float[4] */
         uniformVal = program->Parameters->ParameterValues[index + offset + k];

         if (basicType == GL_INT) {
            /* convert user's ints to floats */
            const GLint *iValues = ((const GLint *) values) + k * elems;
            for (i = 0; i < elems; i++) {
               uniformVal[i] = (GLfloat) iValues[i];
            }
         }
         else if (basicType == GL_UNSIGNED_INT) {
            /* convert user's uints to floats */
            const GLuint *iValues = ((const GLuint *) values) + k * elems;
            for (i = 0; i < elems; i++) {
               uniformVal[i] = (GLfloat) iValues[i];
            }
         }
         else {
            const GLfloat *fValues = ((const GLfloat *) values) + k * elems;
            assert(basicType == GL_FLOAT);
            for (i = 0; i < elems; i++) {
               uniformVal[i] = fValues[i];
            }
         }

         /* if the uniform is bool-valued, convert to 1.0 or 0.0 */
         if (isUniformBool) {
            for (i = 0; i < elems; i++) {
               uniformVal[i] = uniformVal[i] ? 1.0f : 0.0f;
            }
         }
      }
   }
}


/**
 * Called via ctx->Driver.Uniform().
 */
static void
_mesa_uniform(GLcontext *ctx, GLint location, GLsizei count,
              const GLvoid *values, GLenum type)
{
   struct gl_shader_program *shProg = ctx->Shader.CurrentProgram;
   struct gl_uniform *uniform;
   GLint elems, offset;

   if (!shProg || !shProg->LinkStatus) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glUniform(program not linked)");
      return;
   }

   if (location == -1)
      return;   /* The standard specifies this as a no-op */

   if (location < -1) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glUniform(location=%d)",
                  location);
      return;
   }

   split_location_offset(&location, &offset);

   if (location < 0 || location >= (GLint) shProg->Uniforms->NumUniforms) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glUniform(location=%d)", location);
      return;
   }

   if (count < 0) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glUniform(count < 0)");
      return;
   }

   elems = _mesa_sizeof_glsl_type(type);

   FLUSH_VERTICES(ctx, _NEW_PROGRAM_CONSTANTS);

   uniform = &shProg->Uniforms->Uniforms[location];

   if (ctx->Shader.Flags & GLSL_UNIFORMS) {
      const GLenum basicType = base_uniform_type(type);
      GLint i;
      printf("Mesa: set program %u uniform %s (loc %d) to: ",
	     shProg->Name, uniform->Name, location);
      if (basicType == GL_INT) {
         const GLint *v = (const GLint *) values;
         for (i = 0; i < count * elems; i++) {
            printf("%d ", v[i]);
         }
      }
      else if (basicType == GL_UNSIGNED_INT) {
         const GLuint *v = (const GLuint *) values;
         for (i = 0; i < count * elems; i++) {
            printf("%u ", v[i]);
         }
      }
      else {
         const GLfloat *v = (const GLfloat *) values;
         assert(basicType == GL_FLOAT);
         for (i = 0; i < count * elems; i++) {
            printf("%g ", v[i]);
         }
      }
      printf("\n");
   }

   /* A uniform var may be used by both a vertex shader and a fragment
    * shader.  We may need to update one or both shader's uniform here:
    */
   if (shProg->VertexProgram) {
      /* convert uniform location to program parameter index */
      GLint index = uniform->VertPos;
      if (index >= 0) {
         set_program_uniform(ctx, &shProg->VertexProgram->Base,
                             index, offset, type, count, elems, values);
      }
   }

   if (shProg->FragmentProgram) {
      /* convert uniform location to program parameter index */
      GLint index = uniform->FragPos;
      if (index >= 0) {
         set_program_uniform(ctx, &shProg->FragmentProgram->Base,
                             index, offset, type, count, elems, values);
      }
   }

   uniform->Initialized = GL_TRUE;
}


/**
 * Set a matrix-valued program parameter.
 */
static void
set_program_uniform_matrix(GLcontext *ctx, struct gl_program *program,
                           GLuint index, GLuint offset,
                           GLuint count, GLuint rows, GLuint cols,
                           GLboolean transpose, const GLfloat *values)
{
   GLuint mat, row, col;
   GLuint src = 0;
   const struct gl_program_parameter * param = &program->Parameters->Parameters[index];
   const GLuint slots = (param->Size + 3) / 4;
   const GLint typeSize = _mesa_sizeof_glsl_type(param->DataType);
   GLint nr, nc;

   /* check that the number of rows, columns is correct */
   get_matrix_dims(param->DataType, &nr, &nc);
   if (rows != nr || cols != nc) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
                  "glUniformMatrix(matrix size mismatch)");
      return;
   }

   if ((GLint) param->Size <= typeSize) {
      /* non-array: count must be at most one; count == 0 is handled by the loop below */
      if (count > 1) {
         _mesa_error(ctx, GL_INVALID_OPERATION,
                     "glUniformMatrix(uniform is not an array)");
         return;
      }
   }

   /*
    * Note: the _columns_ of a matrix are stored in program registers, not
    * the rows.  So, the loops below look a little funny.
    * XXX could optimize this a bit...
    */

   /* loop over matrices */
   for (mat = 0; mat < count; mat++) {

      /* each matrix: */
      for (col = 0; col < cols; col++) {
         GLfloat *v;
         if (offset >= slots) {
            /* Ignore writes beyond the end of (the used part of) an array */
            return;
         }
         v = program->Parameters->ParameterValues[index + offset];
         for (row = 0; row < rows; row++) {
            if (transpose) {
               v[row] = values[src + row * cols + col];
            }
            else {
               v[row] = values[src + col * rows + row];
            }
         }

         offset++;
      }

      src += rows * cols;  /* next matrix */
   }
}


/**
 * Called by ctx->Driver.UniformMatrix().
 * Note: cols=2, rows=4  ==>  array[2] of vec4
 */
static void
_mesa_uniform_matrix(GLcontext *ctx, GLint cols, GLint rows,
                     GLint location, GLsizei count,
                     GLboolean transpose, const GLfloat *values)
{
   struct gl_shader_program *shProg = ctx->Shader.CurrentProgram;
   struct gl_uniform *uniform;
   GLint offset;

   if (!shProg || !shProg->LinkStatus) {
      _mesa_error(ctx, GL_INVALID_OPERATION,
         "glUniformMatrix(program not linked)");
      return;
   }

   if (location == -1)
      return;   /* The standard specifies this as a no-op */

   if (location < -1) {
      _mesa_error(ctx, GL_INVALID_OPERATION, "glUniformMatrix(location)");
      return;
   }

   split_location_offset(&location, &offset);

   if (location < 0 || location >= (GLint) shProg->Uniforms->NumUniforms) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glUniformMatrix(location)");
      return;
   }
   if (values == NULL) {
      _mesa_error(ctx, GL_INVALID_VALUE, "glUniformMatrix");
      return;
   }

   FLUSH_VERTICES(ctx, _NEW_PROGRAM_CONSTANTS);

   uniform = &shProg->Uniforms->Uniforms[location];

   if (shProg->VertexProgram) {
      /* convert uniform location to program parameter index */
      GLint index = uniform->VertPos;
      if (index >= 0) {
         set_program_uniform_matrix(ctx, &shProg->VertexProgram->Base,
                                    index, offset,
                                    count, rows, cols, transpose, values);
      }
   }

   if (shProg->FragmentProgram) {
      /* convert uniform location to program parameter index */
      GLint index = uniform->FragPos;
      if (index >= 0) {
         set_program_uniform_matrix(ctx, &shProg->FragmentProgram->Base,
                                    index, offset,
                                    count, rows, cols, transpose, values);
      }
   }

   uniform->Initialized = GL_TRUE;
}



void
_mesa_init_uniform_functions(struct dd_function_table *driver)
{
   driver->GetActiveUniform = _mesa_get_active_uniform;
   driver->GetUniformfv = _mesa_get_uniformfv;
   driver->GetUniformiv = _mesa_get_uniformiv;
   driver->GetUniformLocation = _mesa_get_uniform_location;
   driver->Uniform = _mesa_uniform;
   driver->UniformMatrix = _mesa_uniform_matrix;
}