Add pure luminance and alpha textures

There should be a difference between these two, but for now we lack a
test case. At the moment they both act as alpha textures.

src/gc_gl.c

@@ -1458,6 +1458,14 @@ void glTexImage2D(GLenum target, GLint level, GLint internalFormat, GLsizei widt
     } else if (internalFormat == GL_LUMINANCE_ALPHA) {
         bytesperpixelinternal = 2;
         gx_format = GX_TF_IA8;
+    } else if (internalFormat == GL_LUMINANCE) {
+        bytesperpixelinternal = 1;
+        gx_format = GX_TF_I8;
+    } else if (internalFormat == GL_ALPHA) {
+        bytesperpixelinternal = 1;
+        /* GX_TF_A8 is not supported by Dolphin and if not properly handed by a
+         * real Wii either. */
+        gx_format = GX_TF_I8;
     } else {
         gx_format = GX_TF_CMPR;
     }
@@ -1534,7 +1542,9 @@ void glTexImage2D(GLenum target, GLint level, GLint internalFormat, GLsizei widt
     // Inconditionally convert to 565 all inputs without alpha channel
     // Alpha inputs may be stripped if the user specifies an alpha-free internal format
     if (bytesperpixelinternal > 0) {
-        unsigned char *tempbuf = malloc(width * height * bytesperpixelinternal);
+        /* Add pixels on each direction so that the scrambling functions can
+         * read whole 4x4 (or 8x4) tiles without bound checking */
+        unsigned char *tempbuf = malloc((width + 7) * (height + 3) * bytesperpixelinternal);
         if (!tempbuf) {
             warning("Failed to allocate memory for texture (%d)", errno);
             set_error(GL_OUT_OF_MEMORY);
@@ -1557,10 +1567,13 @@ void glTexImage2D(GLenum target, GLint level, GLint internalFormat, GLsizei widt
             } else if (internalFormat == GL_LUMINANCE_ALPHA) {
                 _ogx_conv_luminance_alpha_to_ia8(data, type, tempbuf, width, height);
             }
+        } else if (format == GL_ALPHA || format == GL_LUMINANCE) {
+            _ogx_conv_intensity_to_i8(data, type, tempbuf, width, height);
         }
 
         // Swap R<->B if necessary
-        if (needswap && internalFormat != GL_LUMINANCE_ALPHA) {
+        if (needswap && bytesperpixelinternal > 1 &&
+            internalFormat != GL_LUMINANCE_ALPHA) {
             if (bytesperpixelinternal == 4)
                 _ogx_swap_rgba(tempbuf, width * height);
             else
@@ -1575,8 +1588,10 @@ void glTexImage2D(GLenum target, GLint level, GLint internalFormat, GLsizei widt
         // Finally write to the dest. buffer scrambling the data
         if (bytesperpixelinternal == 4) {
             _ogx_scramble_4b(tempbuf, dst_addr, width, height);
-        } else {
+        } else if (bytesperpixelinternal == 2) {
             _ogx_scramble_2b((unsigned short *)tempbuf, dst_addr, width, height);
+        } else if (bytesperpixelinternal == 1) {
+            _ogx_scramble_1b(tempbuf, dst_addr, width, height);
         }
         free(tempbuf);
 

src/pixels.c

@@ -35,6 +35,7 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "debug.h"
 #include <math.h>
 #include <string.h>
+#include <sys/param.h>
 
 #define FLOAT_TO_BYTE(f) ((GLbyte)(f * 255.0) & 0xff)
 
@@ -164,6 +165,32 @@ void _ogx_conv_rgba_to_rgba32(const void *data, GLenum type,
     }
 }
 
+static void conv_intensityf_to_i8(const float *src, void *dst, int numpixels)
+{
+    uint32_t *out = dst;
+    while (numpixels--) {
+        *out++ = FLOAT_TO_BYTE(src[0]);
+        src++;
+    }
+}
+
+void _ogx_conv_intensity_to_i8(const void *data, GLenum type,
+                               void *dest, int width, int height)
+{
+    int numpixels = width * height;
+    switch (type) {
+    case GL_BYTE:
+    case GL_UNSIGNED_BYTE:
+        memcpy(dest, data, numpixels);
+        break;
+    case GL_FLOAT:
+        conv_intensityf_to_i8(data, dest, numpixels);
+        break;
+    default:
+        warning("Unsupported texture format %d", type);
+    }
+}
+
 static void conv_laf_to_ia8(const float *src, void *dst, int numpixels)
 {
     uint16_t *out = dst;
@@ -206,6 +233,23 @@ void _ogx_conv_rgba_to_luminance_alpha(unsigned char *src, void *dst,
 }
 
 // 4x4 tile scrambling
+/* 1b texel scrambling */
+void _ogx_scramble_1b(void *src, void *dst, int width, int height)
+{
+    uint64_t *s = src;
+    uint64_t *p = dst;
+
+    int width_blocks = (width + 7) / 8;
+    for (int y = 0; y < height; y += 4) {
+        int rows = MIN(height - y, 4);
+        for (int x = 0; x < width_blocks; x++) {
+            for (int row = 0; row < rows; row++) {
+                *p++ = s[(y + row) * width_blocks + x];
+            }
+        }
+    }
+}
+
 // 2b texel scrambling
 void _ogx_scramble_2b(unsigned short *src, void *dst,
                       const unsigned int width, const unsigned int height)

src/pixels.h

@@ -47,6 +47,9 @@ void _ogx_conv_luminance_alpha_to_ia8(const void *data, GLenum type,
                                       void *dest, int width, int height);
 void _ogx_conv_rgba_to_luminance_alpha(unsigned char *src, void *dst,
                                        const unsigned int width, const unsigned int height);
+void _ogx_conv_intensity_to_i8(const void *data, GLenum type,
+                               void *dest, int width, int height);
+void _ogx_scramble_1b(void *src, void *dst, int width, int height);
 void _ogx_scramble_2b(unsigned short *src, void *dst,
                       const unsigned int width, const unsigned int height);
 void _ogx_scramble_4b(unsigned char *src, void *dst,