+static BOOL gen_nv12_read(struct wined3d_shader_buffer *buffer, GLenum textype,
+ char *luminance)
+{
+ const char *tex;
+ static const float nv12_coef[]
+ = {2.0f / 3.0f, 1.0f / 3.0f, 1.0f, 1.0f};
+
+ switch (textype)
+ {
+ case GL_TEXTURE_2D:
+ tex = "2D";
+ break;
+ case GL_TEXTURE_RECTANGLE_ARB:
+ tex = "RECT";
+ break;
+ default:
+ FIXME("Implement nv12 correction for non-2d, non-rect textures\n");
+ return FALSE;
+ }
+
+ /* NV12 surfaces contain a WxH sized luminance plane, followed by a (W/2)x(H/2)
+ * sized plane where each component is an UV pair. So the effective
+ * bitdepth is 12 bits per pixel If the whole texture is interpreted as luminance
+ * data it looks approximately like this:
+ *
+ * +----------------------------------+----
+ * | |
+ * | |
+ * | |
+ * | |
+ * | | 2
+ * | LUMINANCE | -
+ * | | 3
+ * | |
+ * | |
+ * | |
+ * | |
+ * +----------------------------------+----
+ * |UVUVUVUVUVUVUVUVUVUVUVUVUVUVUVUVUV|
+ * |UVUVUVUVUVUVUVUVUVUVUVUVUVUVUVUVUV|
+ * | | 1
+ * | | -
+ * | | 3
+ * | |
+ * | |
+ * +----------------------------------+----
+ *
+ * When reading from rectangle textures, keep in mind that the input y coordinates
+ * go from 0 to d3d_height, whereas the opengl texture height is 1.5 * d3d_height. */
+
+ shader_addline(buffer, "PARAM nv12_coef = ");
+ shader_arb_append_imm_vec4(buffer, nv12_coef);
+ shader_addline(buffer, ";\n");
+
+ shader_addline(buffer, "MOV texcrd, fragment.texcoord[0];\n");
+ /* We only have half the number of chroma pixels. */
+ shader_addline(buffer, "MUL texcrd.x, texcrd.x, coef.y;\n");
+
+ if (textype == GL_TEXTURE_2D)
+ {
+ shader_addline(buffer, "RCP chroma.w, size.x;\n");
+ shader_addline(buffer, "RCP chroma.z, size.y;\n");
+
+ shader_addline(buffer, "MAD texcrd.y, texcrd.y, nv12_coef.y, nv12_coef.x;\n");
+
+ /* We must not allow filtering horizontally, this would mix U and V.
+ * Vertical filtering is ok. However, bear in mind that the pixel center is at
+ * 0.5, so add 0.5. */
+
+ /* Convert to non-normalized coordinates so we can find the
+ * individual pixel. */
+ shader_addline(buffer, "MUL texcrd.x, texcrd.x, size.x;\n");
+ shader_addline(buffer, "FLR texcrd.x, texcrd.x;\n");
+ /* Multiply by 2 since chroma components are stored in UV pixel pairs,
+ * add 0.5 to hit the center of the pixel. */
+ shader_addline(buffer, "MAD texcrd.x, texcrd.x, coef.z, coef.y;\n");
+
+ /* Convert back to normalized coordinates. */
+ shader_addline(buffer, "MUL texcrd.x, texcrd.x, chroma.w;\n");
+
+ /* Clamp, keep the half pixel origin in mind. */
+ shader_addline(buffer, "MAD temp.y, coef.y, chroma.z, nv12_coef.x;\n");
+ shader_addline(buffer, "MAX texcrd.y, temp.y, texcrd.y;\n");
+ shader_addline(buffer, "MAD temp.y, -coef.y, chroma.z, nv12_coef.z;\n");
+ shader_addline(buffer, "MIN texcrd.y, temp.y, texcrd.y;\n");
+ }
+ else
+ {
+ /* Read from [size - size+size/2] */
+ shader_addline(buffer, "MAD texcrd.y, texcrd.y, coef.y, size.y;\n");
+
+ shader_addline(buffer, "FLR texcrd.x, texcrd.x;\n");
+ /* Multiply by 2 since chroma components are stored in UV pixel pairs,
+ * add 0.5 to hit the center of the pixel. */
+ shader_addline(buffer, "MAD texcrd.x, texcrd.x, coef.z, coef.y;\n");
+
+ /* Clamp */
+ shader_addline(buffer, "MAD temp.y, size.y, coef.y, size.y;\n");
+ shader_addline(buffer, "ADD temp.y, temp.y, -coef.y;\n");
+ shader_addline(buffer, "MIN texcrd.y, temp.y, texcrd.y;\n");
+ shader_addline(buffer, "ADD temp.y, size.y, coef.y;\n");
+ shader_addline(buffer, "MAX texcrd.y, temp.y, texcrd.y;\n");
+ }
+ /* Read the texture, put the result into the output register. */
+ shader_addline(buffer, "TEX temp, texcrd, texture[0], %s;\n", tex);
+ shader_addline(buffer, "MOV chroma.y, temp.w;\n");
+
+ if (textype == GL_TEXTURE_2D)
+ {
+ /* Add 1/size.x */
+ shader_addline(buffer, "ADD texcrd.x, texcrd.x, chroma.w;\n");
+ }
+ else
+ {
+ /* Add 1 */
+ shader_addline(buffer, "ADD texcrd.x, texcrd.x, coef.x;\n");
+ }
+ shader_addline(buffer, "TEX temp, texcrd, texture[0], %s;\n", tex);
+ shader_addline(buffer, "MOV chroma.x, temp.w;\n");
+
+ /* Sample the luminance value. It is in the top 2/3rd of the texture, so scale the y coordinate.
+ * Clamp the y coordinate to prevent the chroma values from bleeding into the sampled luminance
+ * values due to filtering. */
+ shader_addline(buffer, "MOV texcrd, fragment.texcoord[0];\n");
+ if (textype == GL_TEXTURE_2D)
+ {
+ /* Multiply the y coordinate by 2/3 and clamp it */
+ shader_addline(buffer, "MUL texcrd.y, texcrd.y, nv12_coef.x;\n");
+ shader_addline(buffer, "MAD temp.y, -coef.y, chroma.w, nv12_coef.x;\n");
+ shader_addline(buffer, "MIN texcrd.y, temp.y, texcrd.y;\n");
+ shader_addline(buffer, "TEX luminance, texcrd, texture[0], %s;\n", tex);
+ }
+ else
+ {
+ /* Reading from texture_rectangles is pretty straightforward, just use the unmodified
+ * texture coordinate. It is still a good idea to clamp it though, since the opengl texture
+ * is bigger
+ */
+ shader_addline(buffer, "ADD temp.x, size.y, -coef.y;\n");
+ shader_addline(buffer, "MIN texcrd.y, texcrd.y, size.x;\n");
+ shader_addline(buffer, "TEX luminance, texcrd, texture[0], %s;\n", tex);
+ }
+ *luminance = 'a';
+
+ return TRUE;
+}
+
+/* Context activation is done by the caller. */
projects / reactos.git / commitdiff