gpu/command_buffer/common/gles2_cmd_utils.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 // This file is here so other GLES2 related files can have a common set of
   6 // includes where appropriate.
   7
   8 #ifndef GPU_COMMAND_BUFFER_COMMON_GLES2_CMD_UTILS_H_
   9 #define GPU_COMMAND_BUFFER_COMMON_GLES2_CMD_UTILS_H_
  10
  11 #include <stdint.h>
  12
  13 #include <limits>
  14 #include <string>
  15 #include <vector>
  16
  17 #include "base/numerics/safe_math.h"
  18 #include "gpu/command_buffer/common/gles2_utils_export.h"
  19
  20 namespace gpu {
  21 namespace gles2 {
  22
  23 // Does a multiply and checks for overflow.  If the multiply did not overflow
  24 // returns true.
  25
  26 // Multiplies 2 32 bit unsigned numbers checking for overflow.
  27 // If there was no overflow returns true.
  28 inline bool SafeMultiplyUint32(uint32_t a, uint32_t b, uint32_t* dst) {
  29   DCHECK(dst);
  30   base::CheckedNumeric<uint32_t> checked = a;
  31   checked *= b;
  32   *dst = checked.ValueOrDefault(0);
  33   return checked.IsValid();
  34 }
  35
  36 // Does an add checking for overflow.  If there was no overflow returns true.
  37 inline bool SafeAddUint32(uint32_t a, uint32_t b, uint32_t* dst) {
  38   DCHECK(dst);
  39   base::CheckedNumeric<uint32_t> checked = a;
  40   checked += b;
  41   *dst = checked.ValueOrDefault(0);
  42   return checked.IsValid();
  43 }
  44
  45 // Does an add checking for overflow.  If there was no overflow returns true.
  46 inline bool SafeAddInt32(int32_t a, int32_t b, int32_t* dst) {
  47   DCHECK(dst);
  48   base::CheckedNumeric<int32_t> checked = a;
  49   checked += b;
  50   *dst = checked.ValueOrDefault(0);
  51   return checked.IsValid();
  52 }
  53
  54 // Utilties for GLES2 support.
  55 class GLES2_UTILS_EXPORT GLES2Util {
  56  public:
  57   static const int kNumFaces = 6;
  58
  59   // Bits returned by GetChannelsForFormat
  60   enum ChannelBits {
  61     kRed = 0x1,
  62     kGreen = 0x2,
  63     kBlue = 0x4,
  64     kAlpha = 0x8,
  65     kDepth = 0x10000,
  66     kStencil = 0x20000,
  67
  68     kRGB = kRed | kGreen | kBlue,
  69     kRGBA = kRGB | kAlpha
  70   };
  71
  72   struct EnumToString {
  73     uint32_t value;
  74     const char* name;
  75   };
  76
  77   GLES2Util()
  78       : num_compressed_texture_formats_(0),
  79         num_shader_binary_formats_(0) {
  80   }
  81
  82   int num_compressed_texture_formats() const {
  83     return num_compressed_texture_formats_;
  84   }
  85
  86   void set_num_compressed_texture_formats(int num_compressed_texture_formats) {
  87     num_compressed_texture_formats_ = num_compressed_texture_formats;
  88   }
  89
  90   int num_shader_binary_formats() const {
  91     return num_shader_binary_formats_;
  92   }
  93
  94   void set_num_shader_binary_formats(int num_shader_binary_formats) {
  95     num_shader_binary_formats_ = num_shader_binary_formats;
  96   }
  97
  98   // Gets the number of values a particular id will return when a glGet
  99   // function is called. If 0 is returned the id is invalid.
 100   int GLGetNumValuesReturned(int id) const;
 101
 102   // Computes the size of a single group of elements from a format and type pair
 103   static uint32_t ComputeImageGroupSize(int format, int type);
 104
 105   // Computes the size of an image row including alignment padding
 106   static bool ComputeImagePaddedRowSize(
 107       int width, int format, int type, int unpack_alignment,
 108       uint32_t* padded_row_size);
 109
 110   // Computes the size of image data for TexImage2D and TexSubImage2D.
 111   // Optionally the unpadded and padded row sizes can be returned. If height < 2
 112   // then the padded_row_size will be the same as the unpadded_row_size since
 113   // padding is not necessary.
 114   static bool ComputeImageDataSizes(
 115       int width, int height, int depth, int format, int type,
 116       int unpack_alignment, uint32_t* size, uint32_t* unpadded_row_size,
 117       uint32_t* padded_row_size);
 118
 119   static size_t RenderbufferBytesPerPixel(int format);
 120
 121   // Return the element's number of bytes.
 122   // For example, GL_FLOAT_MAT3 returns sizeof(GLfloat).
 123   static uint32_t GetElementSizeForUniformType(int type);
 124   // Return the number of elements.
 125   // For example, GL_FLOAT_MAT3 returns 9.
 126   static uint32_t GetElementCountForUniformType(int type);
 127
 128   static size_t GetGLTypeSizeForTexturesAndBuffers(uint32_t type);
 129
 130   static size_t GetGLTypeSizeForPathCoordType(uint32_t type);
 131
 132   static uint32_t GLErrorToErrorBit(uint32_t gl_error);
 133
 134   static uint32_t GLErrorBitToGLError(uint32_t error_bit);
 135
 136   static uint32_t IndexToGLFaceTarget(int index);
 137
 138   static size_t GLTargetToFaceIndex(uint32_t target);
 139
 140   static uint32_t GetPreferredGLReadPixelsFormat(uint32_t internal_format);
 141
 142   static uint32_t GetPreferredGLReadPixelsType(
 143       uint32_t internal_format, uint32_t texture_type);
 144
 145   // Returns a bitmask for the channels the given format supports.
 146   // See ChannelBits.
 147   static uint32_t GetChannelsForFormat(int format);
 148
 149   // Returns a bitmask for the channels the given attachment type needs.
 150   static uint32_t GetChannelsNeededForAttachmentType(
 151       int type, uint32_t max_color_attachments);
 152
 153   // Return true if value is neither a power of two nor zero.
 154   static bool IsNPOT(uint32_t value) {
 155     return (value & (value - 1)) != 0;
 156   }
 157
 158   // Return true if value is a power of two or zero.
 159   static bool IsPOT(uint32_t value) {
 160     return (value & (value - 1)) == 0;
 161   }
 162
 163   static std::string GetStringEnum(uint32_t value);
 164   static std::string GetStringBool(uint32_t value);
 165   static std::string GetStringError(uint32_t value);
 166
 167   // Parses a uniform name.
 168   //   array_pos: the position of the last '[' character in name.
 169   //   element_index: the index of the array element specifed in the name.
 170   //   getting_array: True if name refers to array.
 171   // returns true of parsing was successful. Returing true does NOT mean
 172   // it's a valid uniform name. On the otherhand, returning false does mean
 173   // it's an invalid uniform name.
 174   static bool ParseUniformName(
 175       const std::string& name,
 176       size_t* array_pos,
 177       int* element_index,
 178       bool* getting_array);
 179
 180   static size_t CalcClearBufferivDataCount(int buffer);
 181   static size_t CalcClearBufferfvDataCount(int buffer);
 182
 183   static void MapUint64ToTwoUint32(
 184       uint64_t v64, uint32_t* v32_0, uint32_t* v32_1);
 185   static uint64_t MapTwoUint32ToUint64(uint32_t v32_0, uint32_t v32_1);
 186
 187   static uint32_t MapBufferTargetToBindingEnum(uint32_t target);
 188
 189   #include "../common/gles2_cmd_utils_autogen.h"
 190
 191  private:
 192   static std::string GetQualifiedEnumString(
 193       const EnumToString* table, size_t count, uint32_t value);
 194
 195   static const EnumToString* const enum_to_string_table_;
 196   static const size_t enum_to_string_table_len_;
 197
 198   int num_compressed_texture_formats_;
 199   int num_shader_binary_formats_;
 200 };
 201
 202 struct GLES2_UTILS_EXPORT ContextCreationAttribHelper {
 203   ContextCreationAttribHelper();
 204
 205   void Serialize(std::vector<int32_t>* attribs) const;
 206   bool Parse(const std::vector<int32_t>& attribs);
 207
 208   // -1 if invalid or unspecified.
 209   int32_t alpha_size;
 210   int32_t blue_size;
 211   int32_t green_size;
 212   int32_t red_size;
 213   int32_t depth_size;
 214   int32_t stencil_size;
 215   int32_t samples;
 216   int32_t sample_buffers;
 217   bool buffer_preserved;
 218   bool bind_generates_resource;
 219   bool fail_if_major_perf_caveat;
 220   bool lose_context_when_out_of_memory;
 221   // 0 if not a WebGL context.
 222   unsigned webgl_version;
 223 };
 224
 225 }  // namespace gles2
 226 }  // namespace gpu
 227
 228 #endif  // GPU_COMMAND_BUFFER_COMMON_GLES2_CMD_UTILS_H_
 229