/**
* Write a span of stencil values to the stencil buffer. This function
* applies the stencil write mask when needed.
* Used for glDraw/CopyPixels
* Input: n - how many pixels
* x, y - location of first pixel
* stencil - the array of stencil values
*/
void
_swrast_write_stencil_span(struct gl_context *ctx, GLint n, GLint x, GLint y,
const GLubyte stencil[] )
{
SWcontext *swrast = SWRAST_CONTEXT(ctx);
struct gl_framebuffer *fb = ctx->DrawBuffer;
struct gl_renderbuffer *rb = fb->Attachment[BUFFER_STENCIL].Renderbuffer;
const GLuint stencilMax = (1 << fb->Visual.stencilBits) - 1;
const GLuint stencilMask = ctx->Stencil.WriteMask[0];
GLubyte *stencilBuf;
if (y < 0 || y >= (GLint) rb->Height ||
x + n <= 0 || x >= (GLint) rb->Width) {
/* span is completely outside framebuffer */
return; /* undefined values OK */
}
if (x < 0) {
GLint dx = -x;
x = 0;
n -= dx;
stencil += dx;
}
if (x + n > (GLint) rb->Width) {
GLint dx = x + n - rb->Width;
n -= dx;
}
if (n <= 0) {
return;
}
stencilBuf = _swrast_pixel_address(rb, x, y);
if ((stencilMask & stencilMax) != stencilMax) {
/* need to apply writemask */
GLubyte *destVals = swrast->stencil_temp.buf1;
GLubyte *newVals = swrast->stencil_temp.buf2;
GLint i;
_mesa_unpack_ubyte_stencil_row(rb->Format, n, stencilBuf, destVals);
for (i = 0; i < n; i++) {
newVals[i]
= (stencil[i] & stencilMask) | (destVals[i] & ~stencilMask);
}
_mesa_pack_ubyte_stencil_row(rb->Format, n, newVals, stencilBuf);
}
else {
_mesa_pack_ubyte_stencil_row(rb->Format, n, stencil, stencilBuf);
}
}
/**
* Compute/return the offset of the stencil value in a pixel.
* For example, if the format is Z24+S8, the position of the stencil bits
* within the 4-byte pixel will be either 0 or 3.
*/
static GLint
get_stencil_offset(gl_format format)
{
const GLubyte one = 1;
GLubyte pixel[MAX_PIXEL_BYTES];
GLint bpp = _mesa_get_format_bytes(format);
GLint i;
assert(_mesa_get_format_bits(format, GL_STENCIL_BITS) == 8);
memset(pixel, 0, sizeof(pixel));
_mesa_pack_ubyte_stencil_row(format, 1, &one, pixel);
for (i = 0; i < bpp; i++) {
if (pixel[i])
return i;
}
_mesa_problem(NULL, "get_stencil_offset() failed\n");
return 0;
}
/**
* Blit color, depth or stencil with GL_NEAREST filtering.
*/
static void
blit_nearest(struct gl_context *ctx,
GLint srcX0, GLint srcY0, GLint srcX1, GLint srcY1,
GLint dstX0, GLint dstY0, GLint dstX1, GLint dstY1,
GLbitfield buffer)
{
struct gl_renderbuffer *readRb, *drawRb;
const GLint srcWidth = ABS(srcX1 - srcX0);
const GLint dstWidth = ABS(dstX1 - dstX0);
const GLint srcHeight = ABS(srcY1 - srcY0);
const GLint dstHeight = ABS(dstY1 - dstY0);
const GLint srcXpos = MIN2(srcX0, srcX1);
const GLint srcYpos = MIN2(srcY0, srcY1);
const GLint dstXpos = MIN2(dstX0, dstX1);
const GLint dstYpos = MIN2(dstY0, dstY1);
const GLboolean invertX = (srcX1 < srcX0) ^ (dstX1 < dstX0);
const GLboolean invertY = (srcY1 < srcY0) ^ (dstY1 < dstY0);
enum mode {
DIRECT,
UNPACK_RGBA_FLOAT,
UNPACK_Z_FLOAT,
UNPACK_Z_INT,
UNPACK_S,
} mode;
GLubyte *srcMap, *dstMap;
GLint srcRowStride, dstRowStride;
GLint dstRow;
GLint pixelSize;
GLvoid *srcBuffer, *dstBuffer;
GLint prevY = -1;
typedef void (*resample_func)(GLint srcWidth, GLint dstWidth,
const GLvoid *srcBuffer, GLvoid *dstBuffer,
GLboolean flip);
resample_func resampleRow;
switch (buffer) {
case GL_COLOR_BUFFER_BIT:
readRb = ctx->ReadBuffer->_ColorReadBuffer;
drawRb = ctx->DrawBuffer->_ColorDrawBuffers[0];
if (readRb->Format == drawRb->Format) {
mode = DIRECT;
pixelSize = _mesa_get_format_bytes(readRb->Format);
} else {
mode = UNPACK_RGBA_FLOAT;
pixelSize = 16;
}
break;
case GL_DEPTH_BUFFER_BIT:
readRb = ctx->ReadBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
drawRb = ctx->DrawBuffer->Attachment[BUFFER_DEPTH].Renderbuffer;
/* Note that for depth/stencil, the formats of src/dst must match. By
* using the core helpers for pack/unpack, we avoid needing to handle
* masking for things like DEPTH copies of Z24S8.
*/
if (readRb->Format == MESA_FORMAT_Z32_FLOAT ||
readRb->Format == MESA_FORMAT_Z32_FLOAT_X24S8) {
mode = UNPACK_Z_FLOAT;
} else {
mode = UNPACK_Z_INT;
}
pixelSize = 4;
break;
case GL_STENCIL_BUFFER_BIT:
readRb = ctx->ReadBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
drawRb = ctx->DrawBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
mode = UNPACK_S;
pixelSize = 1;
break;
default:
_mesa_problem(ctx, "unexpected buffer in blit_nearest()");
return;
}
/* choose row resampler */
switch (pixelSize) {
case 1:
resampleRow = resample_row_1;
break;
case 2:
resampleRow = resample_row_2;
break;
case 4:
resampleRow = resample_row_4;
break;
case 8:
resampleRow = resample_row_8;
break;
case 16:
resampleRow = resample_row_16;
break;
default:
_mesa_problem(ctx, "unexpected pixel size (%d) in blit_nearest",
pixelSize);
return;
}
if (readRb == drawRb) {
/* map whole buffer for read/write */
/* XXX we could be clever and just map the union region of the
* source and dest rects.
*/
GLubyte *map;
GLint rowStride;
GLint formatSize = _mesa_get_format_bytes(readRb->Format);
ctx->Driver.MapRenderbuffer(ctx, readRb, 0, 0,
readRb->Width, readRb->Height,
GL_MAP_READ_BIT | GL_MAP_WRITE_BIT,
&map, &rowStride);
if (!map) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFramebuffer");
return;
}
srcMap = map + srcYpos * rowStride + srcXpos * formatSize;
dstMap = map + dstYpos * rowStride + dstXpos * formatSize;
/* this handles overlapping copies */
if (srcY0 < dstY0) {
/* copy in reverse (top->down) order */
srcMap += rowStride * (readRb->Height - 1);
dstMap += rowStride * (readRb->Height - 1);
srcRowStride = -rowStride;
dstRowStride = -rowStride;
}
else {
/* copy in normal (bottom->up) order */
srcRowStride = rowStride;
dstRowStride = rowStride;
}
}
else {
/* different src/dst buffers */
ctx->Driver.MapRenderbuffer(ctx, readRb,
srcXpos, srcYpos,
srcWidth, srcHeight,
GL_MAP_READ_BIT, &srcMap, &srcRowStride);
if (!srcMap) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFramebuffer");
return;
}
ctx->Driver.MapRenderbuffer(ctx, drawRb,
dstXpos, dstYpos,
dstWidth, dstHeight,
GL_MAP_WRITE_BIT, &dstMap, &dstRowStride);
if (!dstMap) {
ctx->Driver.UnmapRenderbuffer(ctx, readRb);
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFramebuffer");
return;
}
}
/* allocate the src/dst row buffers */
srcBuffer = malloc(pixelSize * srcWidth);
if (!srcBuffer) {
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBufferEXT");
return;
}
dstBuffer = malloc(pixelSize * dstWidth);
if (!dstBuffer) {
free(srcBuffer);
_mesa_error(ctx, GL_OUT_OF_MEMORY, "glBlitFrameBufferEXT");
return;
}
for (dstRow = 0; dstRow < dstHeight; dstRow++) {
GLint srcRow = (dstRow * srcHeight) / dstHeight;
GLubyte *dstRowStart = dstMap + dstRowStride * dstRow;
ASSERT(srcRow >= 0);
ASSERT(srcRow < srcHeight);
if (invertY) {
srcRow = srcHeight - 1 - srcRow;
}
/* get pixel row from source and resample to match dest width */
if (prevY != srcRow) {
GLubyte *srcRowStart = srcMap + srcRowStride * srcRow;
switch (mode) {
case DIRECT:
memcpy(srcBuffer, srcRowStart, pixelSize * srcWidth);
break;
case UNPACK_RGBA_FLOAT:
_mesa_unpack_rgba_row(readRb->Format, srcWidth, srcRowStart,
srcBuffer);
break;
case UNPACK_Z_FLOAT:
_mesa_unpack_float_z_row(readRb->Format, srcWidth, srcRowStart,
srcBuffer);
break;
case UNPACK_Z_INT:
_mesa_unpack_uint_z_row(readRb->Format, srcWidth, srcRowStart,
srcBuffer);
break;
case UNPACK_S:
_mesa_unpack_ubyte_stencil_row(readRb->Format, srcWidth,
srcRowStart, srcBuffer);
break;
}
(*resampleRow)(srcWidth, dstWidth, srcBuffer, dstBuffer, invertX);
prevY = srcRow;
}
/* store pixel row in destination */
switch (mode) {
case DIRECT:
memcpy(dstRowStart, dstBuffer, pixelSize * srcWidth);
break;
case UNPACK_RGBA_FLOAT:
_mesa_pack_float_rgba_row(drawRb->Format, dstWidth, dstBuffer,
dstRowStart);
break;
case UNPACK_Z_FLOAT:
_mesa_pack_float_z_row(drawRb->Format, dstWidth, dstBuffer,
dstRowStart);
break;
case UNPACK_Z_INT:
_mesa_pack_uint_z_row(drawRb->Format, dstWidth, dstBuffer,
dstRowStart);
break;
case UNPACK_S:
_mesa_pack_ubyte_stencil_row(drawRb->Format, dstWidth, dstBuffer,
dstRowStart);
break;
}
}
free(srcBuffer);
free(dstBuffer);
ctx->Driver.UnmapRenderbuffer(ctx, readRb);
if (drawRb != readRb) {
ctx->Driver.UnmapRenderbuffer(ctx, drawRb);
}
}
