mesa: reimplement IROUND(), add F_TO_I()

[mesa.git] / src / mesa / main / readpix.c

diff --git a/src/mesa/main/readpix.c b/src/mesa/main/readpix.c
index 0f429ab2242c1dc5827f0c8782d1ad5d7061d179..1381110495f70ff3c877404b9114d34381402a31 100644 (file)
--- a/src/mesa/main/readpix.c
+++ b/src/mesa/main/readpix.c
@@ -208,6 +208,11 @@ read_stencil_pixels( struct gl_context *ctx,
    ctx->Driver.UnmapRenderbuffer(ctx, rb);
 }
 
+
+/**
+ * Try to do glReadPixels of RGBA data using a simple memcpy or swizzle.
+ * \return GL_TRUE if successful, GL_FALSE otherwise (use the slow path)
+ */
 static GLboolean
 fast_read_rgba_pixels_memcpy( struct gl_context *ctx,
                              GLint x, GLint y,
@@ -220,9 +225,33 @@ fast_read_rgba_pixels_memcpy( struct gl_context *ctx,
    struct gl_renderbuffer *rb = ctx->ReadBuffer->_ColorReadBuffer;
    GLubyte *dst, *map;
    int dstStride, stride, j, texelBytes;
+   GLboolean swizzle_rb = GL_FALSE, copy_xrgb = GL_FALSE;
+
+   /* XXX we could check for other swizzle/special cases here as needed */
+   if (rb->Format == MESA_FORMAT_RGBA8888_REV &&
+       format == GL_BGRA &&
+       type == GL_UNSIGNED_INT_8_8_8_8_REV &&
+       !ctx->Pack.SwapBytes) {
+      swizzle_rb = GL_TRUE;
+   }
+   else if (rb->Format == MESA_FORMAT_XRGB8888 &&
+       format == GL_BGRA &&
+       type == GL_UNSIGNED_INT_8_8_8_8_REV &&
+       !ctx->Pack.SwapBytes) {
+      copy_xrgb = GL_TRUE;
+   }
+   else if (!_mesa_format_matches_format_and_type(rb->Format, format, type,
+                                                  ctx->Pack.SwapBytes))
+      return GL_FALSE;
+
+   /* If the format is unsigned normalized then we can ignore clamping
+    * because the values are already in the range [0,1] so it won't
+    * have any effect anyway.
+    */
+   if (_mesa_get_format_datatype(rb->Format) == GL_UNSIGNED_NORMALIZED)
+      transferOps &= ~IMAGE_CLAMP_BIT;
 
-   if (!_mesa_format_matches_format_and_type(rb->Format, format, type,
-                                             ctx->Pack.SwapBytes))
+   if (transferOps)
       return GL_FALSE;
 
    dstStride = _mesa_image_row_stride(packing, width, format, type);
@@ -237,10 +266,39 @@ fast_read_rgba_pixels_memcpy( struct gl_context *ctx,
    }
 
    texelBytes = _mesa_get_format_bytes(rb->Format);
-   for (j = 0; j < height; j++) {
-      memcpy(dst, map, width * texelBytes);
-      dst += dstStride;
-      map += stride;
+
+   if (swizzle_rb) {
+      /* swap R/B */
+      for (j = 0; j < height; j++) {
+         int i;
+         for (i = 0; i < width; i++) {
+            GLuint *dst4 = (GLuint *) dst, *map4 = (GLuint *) map;
+            GLuint pixel = map4[i];
+            dst4[i] = (pixel & 0xff00ff00)
+                   | ((pixel & 0x00ff0000) >> 16)
+                   | ((pixel & 0x000000ff) << 16);
+         }
+         dst += dstStride;
+         map += stride;
+      }
+   } else if (copy_xrgb) {
+      /* convert xrgb -> argb */
+      for (j = 0; j < height; j++) {
+         GLuint *dst4 = (GLuint *) dst, *map4 = (GLuint *) map;
+         int i;
+         for (i = 0; i < width; i++) {
+            dst4[i] = map4[i] | 0xff000000;  /* set A=0xff */
+         }
+         dst += dstStride;
+         map += stride;
+      }
+   } else {
+      /* just memcpy */
+      for (j = 0; j < height; j++) {
+         memcpy(dst, map, width * texelBytes);
+         dst += dstStride;
+         map += stride;
+      }
    }
 
    ctx->Driver.UnmapRenderbuffer(ctx, rb);
@@ -281,10 +339,14 @@ slow_read_rgba_pixels( struct gl_context *ctx,
    for (j = 0; j < height; j++) {
       if (_mesa_is_integer_format(format)) {
         _mesa_unpack_uint_rgba_row(rbFormat, width, map, (GLuint (*)[4]) rgba);
+         _mesa_rebase_rgba_uint(width, (GLuint (*)[4]) rgba,
+                                rb->_BaseFormat);
         _mesa_pack_rgba_span_int(ctx, width, (GLuint (*)[4]) rgba, format,
                                   type, dst);
       } else {
         _mesa_unpack_rgba_row(rbFormat, width, map, (GLfloat (*)[4]) rgba);
+         _mesa_rebase_rgba_float(width, (GLfloat (*)[4]) rgba,
+                                 rb->_BaseFormat);
         _mesa_pack_rgba_span_float(ctx, width, (GLfloat (*)[4]) rgba, format,
                                     type, dst, packing, transferOps);
       }
@@ -320,13 +382,11 @@ read_rgba_pixels( struct gl_context *ctx,
       transferOps |= IMAGE_CLAMP_BIT;
    }
 
-   if (!transferOps) {
-      /* Try the optimized paths first. */
-      if (fast_read_rgba_pixels_memcpy(ctx, x, y, width, height,
-                                      format, type, pixels, packing,
-                                      transferOps)) {
-        return;
-      }
+   /* Try the optimized paths first. */
+   if (fast_read_rgba_pixels_memcpy(ctx, x, y, width, height,
+                                    format, type, pixels, packing,
+                                    transferOps)) {
+      return;
    }
 
    slow_read_rgba_pixels(ctx, x, y, width, height,
@@ -641,6 +701,12 @@ _mesa_ReadnPixelsARB( GLint x, GLint y, GLsizei width, GLsizei height,
       return;
    }
 
+   if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
+      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
+                  "glReadPixels(incomplete framebuffer)" );
+      return;
+   }
+
    /* Check that the destination format and source buffer are both
     * integer-valued or both non-integer-valued.
     */
@@ -655,12 +721,6 @@ _mesa_ReadnPixelsARB( GLint x, GLint y, GLsizei width, GLsizei height,
       }
    }
 
-   if (ctx->ReadBuffer->_Status != GL_FRAMEBUFFER_COMPLETE_EXT) {
-      _mesa_error(ctx, GL_INVALID_FRAMEBUFFER_OPERATION_EXT,
-                  "glReadPixels(incomplete framebuffer)" );
-      return;
-   }
-
    if (ctx->ReadBuffer->Name != 0 && ctx->ReadBuffer->Visual.samples > 0) {
       _mesa_error(ctx, GL_INVALID_OPERATION, "glReadPixels(multisample FBO)");
       return;