[Mesa-dev] [PATCH 03/27] mesa: Add decoding functions for GL_COMPRESSED_RGB8_ETC2

Ian Romanick idr at freedesktop.org
Tue Nov 6 15:16:33 PST 2012


On 10/19/2012 04:28 PM, Anuj Phogat wrote:
> Signed-off-by: Anuj Phogat <anuj.phogat at gmail.com>
> ---
>   src/mesa/main/texcompress_etc.c |  460 ++++++++++++++++++++++++++++++++++++++-
>   src/mesa/main/texcompress_etc.h |   15 +-
>   2 files changed, 466 insertions(+), 9 deletions(-)
>
> diff --git a/src/mesa/main/texcompress_etc.c b/src/mesa/main/texcompress_etc.c
> index c645f52..cf8b687 100644
> --- a/src/mesa/main/texcompress_etc.c
> +++ b/src/mesa/main/texcompress_etc.c
> @@ -23,6 +23,8 @@
>
>   /**
>    * \file texcompress_etc.c
> + * Supported ETC2 texture formats are:
> + * GL_COMPRESSED_RGB8_ETC2
>    * GL_OES_compressed_ETC1_RGB8_texture support.
>    */
>
> @@ -34,14 +36,25 @@
>   #include "macros.h"
>   #include "swrast/s_context.h"
>
> -GLboolean
> -_mesa_texstore_etc1_rgb8(TEXSTORE_PARAMS)
> -{
> -   /* GL_ETC1_RGB8_OES is only valid in glCompressedTexImage2D */
> -   ASSERT(0);
> +#define true 1
> +#define false 0
>
> -   return GL_FALSE;
> -}
> +struct etc2_block {
> +   int flipped;
> +   int distance;
> +   uint32_t pixel_indices;
> +   const int *modifier_tables[2];
> +   GLboolean is_ind_mode;
> +   GLboolean is_diff_mode;
> +   GLboolean is_t_mode;
> +   GLboolean is_h_mode;
> +   GLboolean is_planar_mode;

Use bool, true, and false from stdbool.h.

> +   GLubyte base_colors[3][3];
> +   GLubyte paint_colors[4][3];
> +};
> +
> +static const int etc2_distance_table[8] = {
> +   3, 6, 11, 16, 23, 32, 41, 64 };
>
>   /* define etc1_parse_block and etc. */
>   #define UINT8_TYPE GLubyte
> @@ -50,6 +63,15 @@ _mesa_texstore_etc1_rgb8(TEXSTORE_PARAMS)
>   #undef TAG
>   #undef UINT8_TYPE
>
> +GLboolean
> +_mesa_texstore_etc1_rgb8(TEXSTORE_PARAMS)
> +{
> +   /* GL_ETC1_RGB8_OES is only valid in glCompressedTexImage2D */
> +   ASSERT(0);
> +
> +   return GL_FALSE;
> +}
> +
>   void
>   _mesa_fetch_texel_2d_f_etc1_rgb8(const struct swrast_texture_image *texImage,
>                                    GLint i, GLint j, GLint k, GLfloat *texel)
> @@ -101,3 +123,427 @@ _mesa_etc1_unpack_rgba8888(uint8_t *dst_row,
>                           src_row, src_stride,
>                           src_width, src_height);
>   }
> +
> +static GLubyte
> +etc2_base_color1_t_mode(const GLubyte *in, GLuint index)
> +{
> +   GLubyte R1a = 0, x = 0;
> +   /* base col 1 = extend_4to8bits( (R1a << 2) | R1b, G1, B1) */
> +   switch(index) {
> +   case 0:
> +      R1a = (in[0] >> 3) & 0x3;
> +      x = ((R1a << 2) | (in[0] & 0x3));
> +      break;
> +   case 1:
> +      x = ((in[1] >> 4) & 0xf);
> +      break;
> +   case 2:
> +      x = (in[1] & 0xf);
> +      break;
> +   default:
> +      /* invalid index */
> +      break;
> +   }
> +   return ((x << 4) | (x & 0xf));
> +}
> +
> +static GLubyte
> +etc2_base_color2_t_mode(const GLubyte *in, GLuint index)
> +{
> +   GLubyte x = 0;
> +   /*extend 4to8bits(R2, G2, B2)*/
> +   switch(index) {
> +   case 0:
> +      x = ((in[2] >> 4) & 0xf );
> +      break;
> +   case 1:
> +      x = (in[2] & 0xf);
> +      break;
> +   case 2:
> +      x = ((in[3] >> 4) & 0xf);
> +      break;
> +   default:
> +      /* invalid index */
> +      break;
> +   }
> +   return ((x << 4) | (x & 0xf));
> +}
> +
> +static GLubyte
> +etc2_base_color1_h_mode(const GLubyte *in, GLuint index)
> +{
> +   GLubyte x = 0;
> +   /* base col 1 = extend 4to8bits(R1, (G1a << 1) | G1b, (B1a << 3) | B1b) */
> +   switch(index) {
> +   case 0:
> +      x = ((in[0] >> 3) & 0xf);
> +      break;
> +   case 1:
> +      x = (((in[0] & 0x7) << 1) | ((in[1] >> 4) & 0x1));
> +      break;
> +   case 2:
> +      x = ((in[1] & 0x8) |
> +           (((in[1] & 0x3) << 1) | ((in[2] >> 7) & 0x1)));
> +      break;
> +   default:
> +      /* invalid index */
> +      break;
> +   }
> +   return ((x << 4) | (x & 0xf));
> + }
> +
> +static GLubyte
> +etc2_base_color2_h_mode(const GLubyte *in, GLuint index)
> +{
> +   GLubyte x = 0;
> +   /* base col 2 = extend 4to8bits(R2, G2, B2) */
> +   switch(index) {
> +   case 0:
> +      x = ((in[2] >> 3) & 0xf );
> +      break;
> +   case 1:
> +      x = (((in[2] & 0x7) << 1) | ((in[3] >> 7) & 0x1));
> +      break;
> +   case 2:
> +      x = ((in[3] >> 3) & 0xf);
> +      break;
> +   default:
> +      /* invalid index */
> +      break;
> +   }
> +   return ((x << 4) | (x & 0xf));
> + }
> +
> +static GLubyte
> +etc2_base_color_o_planar(const GLubyte *in, GLuint index)
> +{
> +   GLuint tmp;
> +   switch(index) {
> +   case 0:
> +      tmp = ((in[0] >> 1) & 0x3f); /* RO */
> +      return ((tmp << 2) | (tmp >> 4));
> +   case 1:
> +      tmp = (((in[0] & 0x1) << 6) | /* GO1 */
> +             ((in[1] >> 1) & 0x3f)); /* GO2 */
> +      return ((tmp << 1) | (tmp >> 6));
> +   case 2:
> +      tmp = (((in[1] & 0x1) << 5) | /* BO1 */
> +             (in[2] & 0x18) | /* BO2 */
> +	     (((in[2] & 0x3) << 1) | ((in[3] >> 7) & 0x1))); /* BO3 */
> +      return ((tmp << 2) | (tmp >> 4));
> +    default:
> +      /* invalid index */
> +      return 0;
> +   }
> +}
> +
> + static GLubyte
> +etc2_base_color_h_planar(const GLubyte *in, GLuint index)
> +{
> +   GLuint tmp;
> +   switch(index) {
> +   case 0:
> +      tmp = (((in[3] & 0x7c) >> 1) | /* RH1 */
> +             (in[3] & 0x1));         /* RH2 */
> +      return ((tmp << 2) | (tmp >> 4));
> +   case 1:
> +      tmp = (in[4] >> 1) & 0x7f; /* GH */
> +      return ((tmp << 1) | (tmp >> 6));
> +   case 2:
> +      tmp = (((in[4] & 0x1) << 5) |
> +             ((in[5] >> 3) & 0x1f)); /* BH */
> +      return ((tmp << 2) | (tmp >> 4));
> +   default:
> +      /* invalid index */
> +      return 0;
> +   }
> +}
> +
> +static GLubyte
> +etc2_base_color_v_planar(const GLubyte *in, GLuint index)
> +{
> +   GLuint tmp;
> +   switch(index) {
> +   case 0:
> +      tmp = (((in[5] & 0x7) << 0x3) |
> +             ((in[6] >> 5) & 0x7)); /* RV */
> +      return ((tmp << 2) | (tmp >> 4));
> +   case 1:
> +      tmp = (((in[6] & 0x1f) << 2) |
> +             ((in[7] >> 6) & 0x3)); /* GV */
> +      return ((tmp << 1) | (tmp >> 6));
> +   case 2:
> +      tmp = in[7] & 0x3f; /* BV */
> +      return ((tmp << 2) | (tmp >> 4));
> +   default:
> +      /* invalid index */
> +      return 0;
> +   }
> +}
> +
> +static GLubyte
> +etc2_clamp(int color)
> +{
> +   /* CLAMP(color, 0, 255) */
> +   return (GLubyte) ((color < 0) ? 0 : ((color > 255) ? 255 : color));
> +}

Just use Mesa's CLAMP macro.

> +
> +static void
> +etc2_parse_block(struct etc2_block *block, const GLubyte *src)
> +{
> +   unsigned i;
> +   GLboolean diffbit = src[3] & 0x2;
> +   static const int lookup[8] = { 0, 1, 2, 3, -4, -3, -2, -1 };
> +
> +   const int R_plus_dR = (src[0] >> 3) + lookup[src[0] & 0x7];
> +   const int G_plus_dG = (src[1] >> 3) + lookup[src[1] & 0x7];
> +   const int B_plus_dB = (src[2] >> 3) + lookup[src[2] & 0x7];
> +
> +   /* Reset the mode flags */
> +   block->is_ind_mode = false;
> +   block->is_diff_mode = false;
> +   block->is_t_mode = false;
> +   block->is_h_mode = false;
> +   block->is_planar_mode = false;
> +
> +   if (!diffbit) {
> +      /* individual mode */
> +      block->is_ind_mode = true;
> +
> +      for (i = 0; i < 3; i++) {
> +         /* Texture decode algorithm is same for individual mode in etc1
> +          * & etc2.
> +          */
> +         block->base_colors[0][i] = etc1_base_color_ind_hi(src[i]);
> +         block->base_colors[1][i] = etc1_base_color_ind_lo(src[i]);
> +      }
> +   }
> +   else if (R_plus_dR < 0 || R_plus_dR > 31){
> +      /* T mode */
> +      block->is_t_mode = true;
> +
> +      for(i = 0; i < 3; i++) {
> +         block->base_colors[0][i] = etc2_base_color1_t_mode(src, i);
> +         block->base_colors[1][i] = etc2_base_color2_t_mode(src, i);
> +      }
> +      /* pick distance */
> +      block->distance =
> +         etc2_distance_table[(((src[3] >> 2) & 0x3) << 1) |
> +	                     (src[3] & 0x1)];
> +
> +      for (i = 0; i < 3; i++) {
> +         block->paint_colors[0][i] = etc2_clamp(block->base_colors[0][i]);
> +         block->paint_colors[1][i] = etc2_clamp(block->base_colors[1][i] +
> +                                                block->distance);
> +         block->paint_colors[2][i] = etc2_clamp(block->base_colors[1][i]);
> +         block->paint_colors[3][i] = etc2_clamp(block->base_colors[1][i] -
> +                                                block->distance);
> +      }
> +   }
> +   else if (G_plus_dG < 0 || G_plus_dG > 31){
> +      /* H mode */
> +      block->is_h_mode = true;
> +      int base_color_1_value, base_color_2_value;
> +
> +      for(i = 0; i < 3; i++) {
> +         block->base_colors[0][i] = etc2_base_color1_h_mode(src, i);
> +         block->base_colors[1][i] = etc2_base_color2_h_mode(src, i);
> +      }
> +
> +      base_color_1_value = (block->base_colors[0][0] << 16) +
> +                           (block->base_colors[0][1] << 8) +
> +			   block->base_colors[0][2];
> +      base_color_2_value = (block->base_colors[1][0] << 16) +
> +                           (block->base_colors[1][1] << 8) +
> +			   block->base_colors[1][2];
> +      /* pick distance */
> +      block->distance =
> +         etc2_distance_table[(src[3] & 0x4) |
> +	                     ((src[3] & 0x1) << 1) |
> +			     (base_color_1_value >= base_color_2_value)];
> +
> +      for (i = 0; i < 3; i++) {
> +         block->paint_colors[0][i] = etc2_clamp(block->base_colors[0][i] +
> +                                                block->distance);
> +         block->paint_colors[1][i] = etc2_clamp(block->base_colors[0][i] -
> +                                                block->distance);
> +         block->paint_colors[2][i] = etc2_clamp(block->base_colors[1][i] +
> +                                                block->distance);
> +         block->paint_colors[3][i] = etc2_clamp(block->base_colors[1][i] -
> +                                                block->distance);
> +      }
> +   }
> +   else if (B_plus_dB < 0 || B_plus_dB > 31){
> +      /* Planar mode */
> +      block->is_planar_mode = true;
> +
> +      for (i = 0; i < 3; i++) {
> +         block->base_colors[0][i] = etc2_base_color_o_planar(src, i);
> +         block->base_colors[1][i] = etc2_base_color_h_planar(src, i);
> +         block->base_colors[2][i] = etc2_base_color_v_planar(src, i);
> +      }
> +   }
> +   else if (diffbit) {
> +      /* differential mode */
> +      block->is_diff_mode = true;
> +
> +      for (i = 0; i < 3; i++) {
> +         /* Texture decode algorithm is same for differential mode in etc1
> +          * & etc2.
> +          */
> +         block->base_colors[0][i] = etc1_base_color_diff_hi(src[i]);
> +         block->base_colors[1][i] = etc1_base_color_diff_lo(src[i]);
> +     }
> +   }
> +
> +   if(block->is_ind_mode || block->is_diff_mode) {
> +      /* pick modifier tables. same for etc1 & etc2 textures */
> +      block->modifier_tables[0] = etc1_modifier_tables[(src[3] >> 5) & 0x7];
> +      block->modifier_tables[1] = etc1_modifier_tables[(src[3] >> 2) & 0x7];
> +      block->flipped = (src[3] & 0x1);
> +   }
> +
> +   block->pixel_indices =
> +      (src[4] << 24) | (src[5] << 16) | (src[6] << 8) | src[7];
> +}
> +
> +static void
> +etc2_fetch_texel(const struct etc2_block *block,
> +      int x, int y, GLubyte *dst)
> +{
> +   const GLubyte *base_color;
> +   int modifier, bit, idx, blk;
> +
> +   /* get pixel index */
> +   bit = y + x * 4;
> +   idx = ((block->pixel_indices >> (15 + bit)) & 0x2) |
> +         ((block->pixel_indices >>      (bit)) & 0x1);
> +
> +   if (block->is_ind_mode || block->is_diff_mode) {
> +      /* Use pixel index and subblock to get the modifier */
> +      blk = (block->flipped) ? (y >= 2) : (x >= 2);
> +      base_color = block->base_colors[blk];
> +      modifier = block->modifier_tables[blk][idx];
> +
> +      dst[0] = etc2_clamp(base_color[0] + modifier);
> +      dst[1] = etc2_clamp(base_color[1] + modifier);
> +      dst[2] = etc2_clamp(base_color[2] + modifier);
> +   }
> +   else if (block->is_t_mode || block->is_h_mode) {
> +      /* Use pixel index to pick one of the paint colors */
> +      dst[0] = block->paint_colors[idx][0];
> +      dst[1] = block->paint_colors[idx][1];
> +      dst[2] = block->paint_colors[idx][2];
> +   }
> +   else if (block->is_planar_mode) {
> +      /* {R(x, y) = clamp255((x × (RH − RO) + y × (RV − RO) + 4 × RO + 2) >> 2)
> +       * {G(x, y) = clamp255((x × (GH − GO) + y × (GV − GO) + 4 × GO + 2) >> 2)
> +       * {B(x, y) = clamp255((x × (BH − BO) + y × (BV − BO) + 4 × BO + 2) >> 2)
> +       */
> +      int red, green, blue;
> +      red = (x * (block->base_colors[1][0] - block->base_colors[0][0]) +
> +             y * (block->base_colors[2][0] - block->base_colors[0][0]) +
> +             4 * block->base_colors[0][0] + 2) >> 2;
> +
> +      green = (x * (block->base_colors[1][1] - block->base_colors[0][1]) +
> +               y * (block->base_colors[2][1] - block->base_colors[0][1]) +
> +               4 * block->base_colors[0][1] + 2) >> 2;
> +
> +      blue = (x * (block->base_colors[1][2] - block->base_colors[0][2]) +
> +              y * (block->base_colors[2][2] - block->base_colors[0][2]) +
> +              4 * block->base_colors[0][2] + 2) >> 2;
> +
> +      dst[0] = etc2_clamp(red);
> +      dst[1] = etc2_clamp(green);
> +      dst[2] = etc2_clamp(blue);
> +  }
> +}
> +
> +static void
> +etc2_unpack_rgb8(uint8_t *dst_row,
> +                 unsigned dst_stride,
> +                 const uint8_t *src_row,
> +                 unsigned src_stride,
> +                 unsigned width,
> +                 unsigned height)
> +{
> +   const unsigned bw = 4, bh = 4, bs = 8, comps = 4;
> +   struct etc2_block block;
> +   unsigned x, y, i, j;
> +
> +   for (y = 0; y < height; y += bh) {
> +      const uint8_t *src = src_row;
> +
> +      for (x = 0; x < width; x+= bw) {
> +         etc2_parse_block(&block, src);
> +
> +         for (j = 0; j < bh; j++) {
> +            uint8_t *dst = dst_row + (y + j) * dst_stride + x * comps;
> +            for (i = 0; i < bw; i++) {
> +               etc2_fetch_texel(&block, i, j, dst);
> +               dst[3] = 255;
> +               dst += comps;
> +            }
> +         }
> +
> +         src += bs;
> +      }
> +
> +      src_row += src_stride;
> +   }
> +}
> +
> +/* ETC2 texture formats are valid in glCompressedTexImage2D and
> + * glCompressedTexSubImage2D functions */
> +GLboolean
> +_mesa_texstore_etc2_rgb8(TEXSTORE_PARAMS)
> +{
> +   ASSERT(0);
> +
> +   return GL_FALSE;
> +}
> +
> +void
> +_mesa_fetch_texel_2d_f_etc2_rgb8(const struct swrast_texture_image *texImage,
> +                                 GLint i, GLint j, GLint k, GLfloat *texel)
> +{
> +   struct etc2_block block;
> +   GLubyte dst[3];
> +   const GLubyte *src;
> +
> +   src = (const GLubyte *) texImage->Map +
> +      (((texImage->RowStride + 3) / 4) * (j / 4) + (i / 4)) * 8;
> +
> +   etc2_parse_block(&block, src);
> +   etc2_fetch_texel(&block, i % 4, j % 4, dst);
> +
> +   texel[RCOMP] = UBYTE_TO_FLOAT(dst[0]);
> +   texel[GCOMP] = UBYTE_TO_FLOAT(dst[1]);
> +   texel[BCOMP] = UBYTE_TO_FLOAT(dst[2]);
> +   texel[ACOMP] = 1.0f;
> +}
> +
> +
> +/**
> + * Decode texture data in format `MESA_FORMAT_ETC2_RGB8`
> + *
> + * The size of the source data must be a multiple of the ETC2 block size
> + * even if the texture image's dimensions are not aligned to 4.
> + *
> + * \param src_width in pixels
> + * \param src_height in pixels
> + * \param dst_stride in bytes
> + */
> +
> +void
> +_mesa_unpack_etc2_format(uint8_t *dst_row,
> +                         unsigned dst_stride,
> +                         const uint8_t *src_row,
> +                         unsigned src_stride,
> +                         unsigned src_width,
> +                         unsigned src_height)
> +{
> +   etc2_unpack_rgb8(dst_row, dst_stride,
> +                    src_row, src_stride,
> +                    src_width, src_height);
> +}
> diff --git a/src/mesa/main/texcompress_etc.h b/src/mesa/main/texcompress_etc.h
> index 411e154..8c6a40d 100644
> --- a/src/mesa/main/texcompress_etc.h
> +++ b/src/mesa/main/texcompress_etc.h
> @@ -34,10 +34,15 @@ struct swrast_texture_image;
>   GLboolean
>   _mesa_texstore_etc1_rgb8(TEXSTORE_PARAMS);
>
> +GLboolean
> +_mesa_texstore_etc2_rgb8(TEXSTORE_PARAMS);
> +
>   void
>   _mesa_fetch_texel_2d_f_etc1_rgb8(const struct swrast_texture_image *texImage,
>                                    GLint i, GLint j, GLint k, GLfloat *texel);
> -
> +void
> +_mesa_fetch_texel_2d_f_etc2_rgb8(const struct swrast_texture_image *texImage,
> +                                 GLint i, GLint j, GLint k, GLfloat *texel);
>   void
>   _mesa_etc1_unpack_rgba8888(uint8_t *dst_row,
>                              unsigned dst_stride,
> @@ -45,5 +50,11 @@ _mesa_etc1_unpack_rgba8888(uint8_t *dst_row,
>                              unsigned src_stride,
>                              unsigned src_width,
>                              unsigned src_height);
> -
> +void
> +_mesa_unpack_etc2_format(uint8_t *dst_row,
> +                         unsigned dst_stride,
> +                         const uint8_t *src_row,
> +                         unsigned src_stride,
> +                         unsigned src_width,
> +                         unsigned src_height);
>   #endif
>
>
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev
>



More information about the mesa-dev mailing list