/* Function: al_clear_to_color
*/
void al_clear_to_color(ALLEGRO_COLOR color)
{
ALLEGRO_BITMAP *target = al_get_target_bitmap();
ASSERT(target);
if (al_get_bitmap_flags(target) & ALLEGRO_MEMORY_BITMAP ||
_al_pixel_format_is_compressed(al_get_bitmap_format(target))) {
_al_clear_bitmap_by_locking(target, &color);
}
else {
ALLEGRO_DISPLAY *display = _al_get_bitmap_display(target);
ASSERT(display);
ASSERT(display->vt);
display->vt->clear(display, &color);
}
}
bool _al_opengl_set_blender(ALLEGRO_DISPLAY *ogl_disp)
{
int op, src_color, dst_color, op_alpha, src_alpha, dst_alpha;
ALLEGRO_COLOR const_color;
const int blend_modes[10] = {
GL_ZERO, GL_ONE, GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA,
GL_SRC_COLOR, GL_DST_COLOR, GL_ONE_MINUS_SRC_COLOR,
GL_ONE_MINUS_DST_COLOR,
#if defined(ALLEGRO_CFG_OPENGLES2) || !defined(ALLEGRO_CFG_OPENGLES)
GL_CONSTANT_COLOR, GL_ONE_MINUS_CONSTANT_COLOR
#else
GL_ONE, GL_ONE
#endif
};
const int blend_equations[3] = {
GL_FUNC_ADD, GL_FUNC_SUBTRACT, GL_FUNC_REVERSE_SUBTRACT
};
(void)ogl_disp;
al_get_separate_blender(&op, &src_color, &dst_color,
&op_alpha, &src_alpha, &dst_alpha);
const_color = al_get_blend_color();
/* glBlendFuncSeparate was only included with OpenGL 1.4 */
#if !defined ALLEGRO_CFG_OPENGLES
if (ogl_disp->ogl_extras->ogl_info.version >= _ALLEGRO_OPENGL_VERSION_1_4) {
#else
/* FIXME: At this time (09/2014) there are a lot of Android phones that
* don't support glBlendFuncSeparate even though they claim OpenGL ES 2.0
* support. Rather than not work on 20-25% of phones, we just don't support
* separate blending on Android for now.
*/
#ifdef ALLEGRO_ANDROID
if (false) {
#else
if (ogl_disp->ogl_extras->ogl_info.version >= _ALLEGRO_OPENGL_VERSION_2_0) {
#endif
#endif
glEnable(GL_BLEND);
#if defined(ALLEGRO_CFG_OPENGLES2) || !defined(ALLEGRO_CFG_OPENGLES)
#ifndef ALLEGRO_ANDROID_HACK_X86_64
glBlendColor(const_color.r, const_color.g, const_color.b, const_color.a);
#endif
#endif
glBlendFuncSeparate(blend_modes[src_color], blend_modes[dst_color],
blend_modes[src_alpha], blend_modes[dst_alpha]);
if (ogl_disp->ogl_extras->ogl_info.version >= _ALLEGRO_OPENGL_VERSION_2_0) {
glBlendEquationSeparate(
blend_equations[op],
blend_equations[op_alpha]);
}
else {
glBlendEquation(blend_equations[op]);
}
}
else {
if (src_color == src_alpha && dst_color == dst_alpha) {
glEnable(GL_BLEND);
#if defined(ALLEGRO_CFG_OPENGLES2) || !defined(ALLEGRO_CFG_OPENGLES)
#ifndef ALLEGRO_ANDROID_HACK_X86_64
glBlendColor(const_color.r, const_color.g, const_color.b, const_color.a);
#endif
#endif
glBlendFunc(blend_modes[src_color], blend_modes[dst_color]);
}
else {
ALLEGRO_ERROR("Blender unsupported with this OpenGL version (%d %d %d %d %d %d)\n",
op, src_color, dst_color, op_alpha, src_alpha, dst_alpha);
return false;
}
}
return true;
}
/* These functions make drawing calls use shaders or the fixed pipeline
* based on what the user has set up. FIXME: OpenGL only right now.
*/
static void vert_ptr_on(ALLEGRO_DISPLAY *display, int n, GLint t, int stride, void *v)
{
/* Only use this shader stuff with GLES2+ or equivalent */
if (display->flags & ALLEGRO_PROGRAMMABLE_PIPELINE) {
#ifdef ALLEGRO_CFG_OPENGL_PROGRAMMABLE_PIPELINE
if (display->ogl_extras->varlocs.pos_loc >= 0) {
glVertexAttribPointer(display->ogl_extras->varlocs.pos_loc, n, t, false, stride, v);
glEnableVertexAttribArray(display->ogl_extras->varlocs.pos_loc);
}
#endif
}
else {
glEnableClientState(GL_VERTEX_ARRAY);
glVertexPointer(n, t, stride, v);
}
}
static void vert_ptr_off(ALLEGRO_DISPLAY *display)
{
if (display->flags & ALLEGRO_PROGRAMMABLE_PIPELINE) {
#ifdef ALLEGRO_CFG_OPENGL_PROGRAMMABLE_PIPELINE
if (display->ogl_extras->varlocs.pos_loc >= 0) {
glDisableVertexAttribArray(display->ogl_extras->varlocs.pos_loc);
}
#endif
}
else {
glDisableClientState(GL_VERTEX_ARRAY);
}
}
static void color_ptr_on(ALLEGRO_DISPLAY *display, int n, GLint t, int stride, void *v)
{
if (display->flags & ALLEGRO_PROGRAMMABLE_PIPELINE) {
#ifdef ALLEGRO_CFG_OPENGL_PROGRAMMABLE_PIPELINE
if (display->ogl_extras->varlocs.color_loc >= 0) {
glVertexAttribPointer(display->ogl_extras->varlocs.color_loc, n, t, false, stride, v);
glEnableVertexAttribArray(display->ogl_extras->varlocs.color_loc);
}
#endif
}
else {
glEnableClientState(GL_COLOR_ARRAY);
glColorPointer(n, t, stride, v);
}
}
static void color_ptr_off(ALLEGRO_DISPLAY *display)
{
if (display->flags & ALLEGRO_PROGRAMMABLE_PIPELINE) {
#ifdef ALLEGRO_CFG_OPENGL_PROGRAMMABLE_PIPELINE
if (display->ogl_extras->varlocs.color_loc >= 0) {
glDisableVertexAttribArray(display->ogl_extras->varlocs.color_loc);
}
#endif
}
else {
glDisableClientState(GL_COLOR_ARRAY);
}
}
static void tex_ptr_on(ALLEGRO_DISPLAY *display, int n, GLint t, int stride, void *v)
{
if (display->flags & ALLEGRO_PROGRAMMABLE_PIPELINE) {
#ifdef ALLEGRO_CFG_OPENGL_PROGRAMMABLE_PIPELINE
if (display->ogl_extras->varlocs.texcoord_loc >= 0) {
glVertexAttribPointer(display->ogl_extras->varlocs.texcoord_loc, n, t, false, stride, v);
glEnableVertexAttribArray(display->ogl_extras->varlocs.texcoord_loc);
}
#endif
}
else {
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glTexCoordPointer(n, t, stride, v);
}
}
static void tex_ptr_off(ALLEGRO_DISPLAY *display)
{
if (display->flags & ALLEGRO_PROGRAMMABLE_PIPELINE) {
#ifdef ALLEGRO_CFG_OPENGL_PROGRAMMABLE_PIPELINE
if (display->ogl_extras->varlocs.texcoord_loc >= 0) {
glDisableVertexAttribArray(display->ogl_extras->varlocs.texcoord_loc);
}
#endif
}
else {
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}
}
/* There's a very nasty bug in Android 2.1 that makes glClear cause
* screen flicker (appears to me it's swapping buffers.) Work around
* by drawing two triangles instead on that OS.
*/
static void ogl_clear_android_2_1_workaround(ALLEGRO_DISPLAY *d,
float r, float g, float b, float a)
{
GLfloat v[8] = {
0, d->h,
0, 0,
d->w, d->h,
d->w, 0
};
GLfloat c[16] = {
r, g, b, a,
r, g, b, a,
r, g, b, a,
r, g, b, a
};
ALLEGRO_TRANSFORM bak1, bak2, t;
al_copy_transform(&bak1, al_get_current_projection_transform());
al_copy_transform(&bak2, al_get_current_transform());
al_identity_transform(&t);
al_orthographic_transform(&t, 0, 0, -1, d->w, d->h, 1);
al_use_projection_transform(&t);
al_identity_transform(&t);
al_use_transform(&t);
_al_opengl_set_blender(d);
vert_ptr_on(d, 2, GL_FLOAT, 2*sizeof(float), v);
color_ptr_on(d, 4, GL_FLOAT, 4*sizeof(float), c);
if (!(d->flags & ALLEGRO_PROGRAMMABLE_PIPELINE)) {
glDisableClientState(GL_NORMAL_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}
glDisable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, 0);
glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
vert_ptr_off(d);
color_ptr_off(d);
al_use_projection_transform(&bak1);
al_use_transform(&bak2);
}
static void ogl_clear(ALLEGRO_DISPLAY *d, ALLEGRO_COLOR *color)
{
ALLEGRO_DISPLAY *ogl_disp = (void *)d;
ALLEGRO_BITMAP *target = al_get_target_bitmap();
ALLEGRO_BITMAP_EXTRA_OPENGL *ogl_target;
float r, g, b, a;
if (target->parent)
target = target->parent;
ogl_target = target->extra;
if ((!ogl_target->is_backbuffer &&
ogl_disp->ogl_extras->opengl_target != target)
|| target->locked)
{
_al_clear_bitmap_by_locking(target, color);
return;
}
al_unmap_rgba_f(*color, &r, &g, &b, &a);
if (ogl_target->is_backbuffer && IS_ANDROID_AND(_al_android_is_os_2_1())) {
ogl_clear_android_2_1_workaround(d, r, g, b, a);
return;
}
glClearColor(r, g, b, a);
glClear(GL_COLOR_BUFFER_BIT);
}
