mesa: add new signed rgba texture format

This is a (partial) backport of the signed texture format support in OGL 3.1.
Since it wasn't promoted from an existing extension roll our own.

1 files changed, 100 insertions, 11 deletions

diff --git a/src/mesa/main/mipmap.c b/src/mesa/main/mipmap.c
index 4a79430c34d..7001211a131 100644
--- a/src/mesa/main/mipmap.c
+++ b/src/mesa/main/mipmap.c
@@ -86,6 +86,21 @@ bytes_per_pixel(GLenum datatype, GLuint comps)
                                 rowD[j][e], rowD[k][e]); \
    } while(0)
 
+#define FILTER_SUM_3D_SIGNED(Aj, Ak, Bj, Bk, Cj, Ck, Dj, Dk) \
+   (Aj + Ak \
+    + Bj + Bk \
+    + Cj + Ck \
+    + Dj + Dk \
+    + 4) / 8
+
+#define FILTER_3D_SIGNED(e) \
+   do { \
+      dst[i][e] = FILTER_SUM_3D_SIGNED(rowA[j][e], rowA[k][e], \
+                                       rowB[j][e], rowB[k][e], \
+                                       rowC[j][e], rowC[k][e], \
+                                       rowD[j][e], rowD[k][e]); \
+   } while(0)
+
 #define FILTER_F_3D(e) \
    do { \
       dst[i][e] = (rowA[j][e] + rowA[k][e] \
@@ -180,6 +195,53 @@ do_row(GLenum datatype, GLuint comps, GLint srcWidth,
       }
    }
 
+   if (datatype == GL_BYTE && comps == 4) {
+      GLuint i, j, k;
+      const GLbyte(*rowA)[4] = (const GLbyte(*)[4]) srcRowA;
+      const GLbyte(*rowB)[4] = (const GLbyte(*)[4]) srcRowB;
+      GLbyte(*dst)[4] = (GLbyte(*)[4]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
+         dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
+         dst[i][3] = (rowA[j][3] + rowA[k][3] + rowB[j][3] + rowB[k][3]) / 4;
+      }
+   }
+   else if (datatype == GL_BYTE && comps == 3) {
+      GLuint i, j, k;
+      const GLbyte(*rowA)[3] = (const GLbyte(*)[3]) srcRowA;
+      const GLbyte(*rowB)[3] = (const GLbyte(*)[3]) srcRowB;
+      GLbyte(*dst)[3] = (GLbyte(*)[3]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
+         dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
+      }
+   }
+   else if (datatype == GL_BYTE && comps == 2) {
+      GLuint i, j, k;
+      const GLbyte(*rowA)[2] = (const GLbyte(*)[2]) srcRowA;
+      const GLbyte(*rowB)[2] = (const GLbyte(*)[2]) srcRowB;
+      GLbyte(*dst)[2] = (GLbyte(*)[2]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
+      }
+   }
+   else if (datatype == GL_BYTE && comps == 1) {
+      GLuint i, j, k;
+      const GLbyte *rowA = (const GLbyte *) srcRowA;
+      const GLbyte *rowB = (const GLbyte *) srcRowB;
+      GLbyte *dst = (GLbyte *) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) / 4;
+      }
+   }
+
    else if (datatype == GL_UNSIGNED_SHORT && comps == 4) {
       GLuint i, j, k;
       const GLushort(*rowA)[4] = (const GLushort(*)[4]) srcRowA;
@@ -470,17 +532,6 @@ do_row(GLenum datatype, GLuint comps, GLint srcWidth,
          dst[i] = (blue << 5) | (green << 2) | red;
       }
    }
-   else if (datatype == GL_BYTE && comps == 2) {
-      GLuint i, j, k;
-      const GLbyte(*rowA)[2] = (const GLbyte(*)[2]) srcRowA;
-      const GLbyte(*rowB)[2] = (const GLbyte(*)[2]) srcRowB;
-      GLbyte(*dst)[2] = (GLbyte(*)[2]) dstRow;
-      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-           i++, j += colStride, k += colStride) {
-         dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) >> 2;
-         dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) >> 2;
-      }
-   }
    else {
       _mesa_problem(NULL, "bad format in do_row()");
    }
@@ -555,6 +606,44 @@ do_row_3D(GLenum datatype, GLuint comps, GLint srcWidth,
          FILTER_3D(0);
       }
    }
+   if ((datatype == GL_BYTE) && (comps == 4)) {
+      DECLARE_ROW_POINTERS(GLbyte, 4);
+
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         FILTER_3D_SIGNED(0);
+         FILTER_3D_SIGNED(1);
+         FILTER_3D_SIGNED(2);
+         FILTER_3D_SIGNED(3);
+      }
+   }
+   else if ((datatype == GL_BYTE) && (comps == 3)) {
+      DECLARE_ROW_POINTERS(GLbyte, 3);
+
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         FILTER_3D_SIGNED(0);
+         FILTER_3D_SIGNED(1);
+         FILTER_3D_SIGNED(2);
+      }
+   }
+   else if ((datatype == GL_BYTE) && (comps == 2)) {
+      DECLARE_ROW_POINTERS(GLbyte, 2);
+
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         FILTER_3D_SIGNED(0);
+         FILTER_3D_SIGNED(1);
+       }
+   }
+   else if ((datatype == GL_BYTE) && (comps == 1)) {
+      DECLARE_ROW_POINTERS(GLbyte, 1);
+
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         FILTER_3D_SIGNED(0);
+      }
+   }
    else if ((datatype == GL_UNSIGNED_SHORT) && (comps == 4)) {
       DECLARE_ROW_POINTERS(GLushort, 4);